SM Batteries


karkauai
 

Hi Amel Cousins,
I know this has been discussed before, but I’m not having any luck searching the site.

I want to replace my current 8 group 27 hybrid batteries (between cranking and deep cycle characteristics) with deep cycle higher AHr batteries. They are only 90 AHr for a total of 360AHr at 24v.I’ve found Crown 130A hrs group 31’s. My battery compartment (very early SM2K) will only hold 8 group 31’s + 1 cranking battery. That would give me a total of 520 A hrs. Does anyone have experience with these?

I know others have used 6v deep cycle batteries. How many can you fit in your battery compartment? Total A-Hrs? Do you have pics of the installation?

I want to stay with lead acid wet cells on the advice of others who say finding AGMs or GelCells may be difficult in remote places (heading for the S Pacific next Spring).

Any/all advice or experience greatly appreciated.
Kent
SM 243
Kristy
St Michaels, MD


Alan Leslie
 

Hi Kent,

We have the bigger battery compartment with 12 x 6V 220Ah AGM batteries with a battery balancing system on each bank to ensure even charging.
I chose AGM because:
No acid spills/fumes
No maintenance (topping up)
High charge acceptance rate 
Low self discharge rate
Previous good experience
We have a 12v 105Ah AGM as a start battery as well.

We cruise in the South Pacific...I wouldn't use that as a basis for choosing what type of battery to have. If you need a new battery of any sort you are unlikely to find the exact same model that you have...even in New Zealand where you can get almost everything. And if your batteries start to fail, the whole lot should be replaced.

My twopenny worth

Cheers
Alan
Elyse SM437 ....Levuka, Fiji


Miles
 

Hi Kent,

 

I am using 8 group 31 deep cycle batteries from NAPA.  I don’t know who that real manufacturer is but they have worked well now for the last three years and they are cheap enough to replace when they start to age.  For starting, I use a NAPA group 31 truck starting battery.  It spins the engine.

In Europe, I had a set of calcium batteries.  They were very good for more than 4 years.  If left alone for 4 months, they didn’t discharge.  They don’t seem to be available in the US.  I have not looked in the Caribbean.  

 

Regards,

 

Miles s/y Ladybug, sm 216 , Le Marin, Martinique


karkauai
 

Thank you all for your replies. I will look into these various options and let you know what I decide.
Kent


greatketch@...
 

Kent,

Just to throw a bit of extra information on the pile, here is my update for our batteries.


They aren't for everybody, but they seem to be doing what we asked of them above and beyond the standard choices.

Bill Kinney
SM160, Harmonie
Cape Eleuthera, Bahamas


karkauai
 

Here I am again, singing the same tune...
In 2018 I bought 8 Crown "deep cycle" group 31s. They were great for about a year, then slowly began to deteriorate.  With 520 AHr and fully solar charged by early afternoon, when new I was waking up to 25.4-25.6v after about 50AHr use overnight.  This slowly deteriorated until I was running the generator before bed to avoid dropping voltage below 24.7.  I nursed them along until July 21 and bought 8 NAPA (Penn)105 AHr group 31s.  They have already failed, after working great initially, in just 5 months.

I charge at 28.5v Abs, 27v Float, and equalize at 31v (on recommendation of Crown engineer).  I have a 105A Magnum  charger/inverter, and 850W solar in 3 pairs, each pair with it's own Victron MPPP controller, and a 60 A alternator using a Balmar external regulator.

My first 3 sets of similar hybrid batteries didn't start to deteriorate until they were 30-36 months old.  This started after I installed solar.  Watching the voltages and solar output closely shows them acting as they are set to act.  Measuring amperage at the primary 25v cable from battery studs to switch, I don't find any excess current flowing with switches on or off.  All batteries measure within 0.1v after disconnecting for 6 hours. All cells have SG 1.019 +/- .001, which does not improve after 6 hrs equalizing at 31v.  All read within .2v of each other after load testing, which shows them barely in the "fair" range.  It doesn't seem to be a matter of one bad battery or cell, or unequal charging...they are all deteriorating at the same rate.

Soooo...
I need new batteries again, and am thinking about AGM golf cart batteries.  So far they are all 11.5" height, and my very early SM2000 has only 10.5" battery box height. I'm also only able to install 8+1 group31 batteries, limiting my total AHr capacity.

I'd like to make the switch to LiFePO4, but insurance is proving to be a problem.  I had hoped by the time my current batteries failed I'd be able to find insurance...alas, they've gone belly up after only a few months.

I'd love to hear any thoughts about my current ( no pun intended) problem, 6v AGMs that will fit my space, Lithium conversion insurance availability (I'm US flagged, but could register elsewhere, I guess). 
--
Kent & Iris
KRISTY
SM243


 

Kent, Doesn't this explain the furling and outhaul motors not working properly?

Batteries are like anchors, there are lots of opinions and most opinions are based on limited comparative experience.

This is what I tell my clients and it is totally my opinion:
The best house battery buy is the basic DEKA Marine Master Deep Cycle DC31DT battery which will last 2 years, maybe 3. At $107 each (Lowes in the US) it seems like a bargain regardless of which battery you compare it to. Sure there are better batteries that will last longer, but none will cost you less per month. There are so many disappointments that have been reported by Amel owners, it is hard to choose something else. But when you buy these DEKAs and they fail in 2 years, remember that was the expectation. 

And don't forget about the DEKA 12-Volt 1000-Amp Marine Start Battery.

This is what 8 DC31DT batteries and 1 DEKA 12-Volt 1000-Amp Marine Start Battery will cost you at Lowes. 

Don't forget to check the water in these batteries. They will not last if you allow them to charge and discharge with low water.

67774066-f4dd-4bf7-9da3-bba60d865215.png




CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Sun, Dec 12, 2021 at 11:36 AM karkauai via groups.io <karkauai=yahoo.com@groups.io> wrote:
Here I am again, singing the same tune...
In 2018 I bought 8 Crown "deep cycle" group 31s. They were great for about a year, then slowly began to deteriorate.  With 520 AHr and fully solar charged by early afternoon, when new I was waking up to 25.4-25.6v after about 50AHr use overnight.  This slowly deteriorated until I was running the generator before bed to avoid dropping voltage below 24.7.  I nursed them along until July 21 and bought 8 NAPA (Penn)105 AHr group 31s.  They have already failed, after working great initially, in just 5 months.

I charge at 28.5v Abs, 27v Float, and equalize at 31v (on recommendation of Crown engineer).  I have a 105A Magnum  charger/inverter, and 850W solar in 3 pairs, each pair with it's own Victron MPPP controller, and a 60 A alternator using a Balmar external regulator.

My first 3 sets of similar hybrid batteries didn't start to deteriorate until they were 30-36 months old.  This started after I installed solar.  Watching the voltages and solar output closely shows them acting as they are set to act.  Measuring amperage at the primary 25v cable from battery studs to switch, I don't find any excess current flowing with switches on or off.  All batteries measure within 0.1v after disconnecting for 6 hours. All cells have SG 1.019 +/- .001, which does not improve after 6 hrs equalizing at 31v.  All read within .2v of each other after load testing, which shows them barely in the "fair" range.  It doesn't seem to be a matter of one bad battery or cell, or unequal charging...they are all deteriorating at the same rate.

Soooo...
I need new batteries again, and am thinking about AGM golf cart batteries.  So far they are all 11.5" height, and my very early SM2000 has only 10.5" battery box height. I'm also only able to install 8+1 group31 batteries, limiting my total AHr capacity.

I'd like to make the switch to LiFePO4, but insurance is proving to be a problem.  I had hoped by the time my current batteries failed I'd be able to find insurance...alas, they've gone belly up after only a few months.

I'd love to hear any thoughts about my current ( no pun intended) problem, 6v AGMs that will fit my space, Lithium conversion insurance availability (I'm US flagged, but could register elsewhere, I guess). 
--
Kent & Iris
KRISTY
SM243


Nick Newington
 

I am going to throw this one out there to the community. it is just an idea...

Has anyone tried a hybrid AGM and Lithium battery bank?

I am thinking it to be 75% AGM and 25% Lithium. All connected together as one bank….I know…..just hear me out…..it is unorthodox and only an idea….up for debate...

Both battery types can be charged at  14v….then when the charge source is turned off

AGM's will drop to about 13.2v, immediately. This is the float voltage for AGM’s.

Lithium will also drop to 13.2v but maintain that voltage until say 20% capacity remains. This is part of the Lithium chemistry.

In a typical cycle, the AGM’s will be kept at float by the Lithium. So only the Lithium part will be used, but there will still be the AGM that can start to share the load after the Lithium bank has been 80% depleted. So in effect one is cycling only the Lithium part…given that Lithium can be cycled many more times than AGM’s this should be cost effective.

In Practice… imagine 8 AGM batteries of 12v 100AH  giving 400AH at 24v.  Normally this would be a typical bank. Cycle down to 75% each night. Thus consuming 100A. 

Now add two Lithiums of also 100AH 12v giving 100AH at 24v. You now have a 500AH bank….

If you still use 100A then the first 80 will come from the Lithiums or until their voltage drops below 13.2v and then the remaining demand will be supplied from the whole bank. in fact as the lithium voltage drops the AGM’s will take over and start to prop up the Lithiums…so that they do not get depleted too low.

When it comes to charging the Lithiums are more efficient and will accept fast charge, and the AGM’s will trickle full all day if there is sufficient solar….

The end result is that for the cost of only two Lithiums you have in effect a very long lasting bank. The AGM’s only cycle a few percent each day but on occasion they can be as required. They are there as reserve and barely cycle thus will last for a long time maybe more than a decade…

If one was to do this one would have to be very careful connecting the Lithiums… the AGM bank would need to be charged to float 13.2v. The Lithiums would need to be discharged to the same voltage 13.2v so when you connect them together there is no current flow between the batteries. It would be dangerous to connect them with say Lithiums at 13.8v and the AGM’s at 12.5v as it would arc at the moment of contact.

Now shout me down and tell my why this is not a good idea….

Remember the objective is to get the best AH for the lowest cost….

Merry Christmas

Nick

S/Y Amelia
AML 54-019

Stored ashore in Leros






On 12 Dec 2021, at 22:17, CW Bill Rouse <brouse@...> wrote:

Kent, Doesn't this explain the furling and outhaul motors not working properly?

Batteries are like anchors, there are lots of opinions and most opinions are based on limited comparative experience.

This is what I tell my clients and it is totally my opinion:
The best house battery buy is the basic DEKA Marine Master Deep Cycle DC31DT battery which will last 2 years, maybe 3. At $107 each (Lowes in the US) it seems like a bargain regardless of which battery you compare it to. Sure there are better batteries that will last longer, but none will cost you less per month. There are so many disappointments that have been reported by Amel owners, it is hard to choose something else. But when you buy these DEKAs and they fail in 2 years, remember that was the expectation. 

And don't forget about the DEKA 12-Volt 1000-Amp Marine Start Battery.

This is what 8 DC31DT batteries and 1 DEKA 12-Volt 1000-Amp Marine Start Battery will cost you at Lowes. 

Don't forget to check the water in these batteries. They will not last if you allow them to charge and discharge with low water.

<67774066-f4dd-4bf7-9da3-bba60d865215.png>




CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
  
View My Training Calendar

On Sun, Dec 12, 2021 at 11:36 AM karkauai via groups.io <karkauai=yahoo.com@groups.io> wrote:
Here I am again, singing the same tune...
In 2018 I bought 8 Crown "deep cycle" group 31s. They were great for about a year, then slowly began to deteriorate.  With 520 AHr and fully solar charged by early afternoon, when new I was waking up to 25.4-25.6v after about 50AHr use overnight.  This slowly deteriorated until I was running the generator before bed to avoid dropping voltage below 24.7.  I nursed them along until July 21 and bought 8 NAPA (Penn)105 AHr group 31s.  They have already failed, after working great initially, in just 5 months.

I charge at 28.5v Abs, 27v Float, and equalize at 31v (on recommendation of Crown engineer).  I have a 105A Magnum  charger/inverter, and 850W solar in 3 pairs, each pair with it's own Victron MPPP controller, and a 60 A alternator using a Balmar external regulator.

My first 3 sets of similar hybrid batteries didn't start to deteriorate until they were 30-36 months old.  This started after I installed solar.  Watching the voltages and solar output closely shows them acting as they are set to act.  Measuring amperage at the primary 25v cable from battery studs to switch, I don't find any excess current flowing with switches on or off.  All batteries measure within 0.1v after disconnecting for 6 hours. All cells have SG 1.019 +/- .001, which does not improve after 6 hrs equalizing at 31v.  All read within .2v of each other after load testing, which shows them barely in the "fair" range.  It doesn't seem to be a matter of one bad battery or cell, or unequal charging...they are all deteriorating at the same rate.

Soooo...
I need new batteries again, and am thinking about AGM golf cart batteries.  So far they are all 11.5" height, and my very early SM2000 has only 10.5" battery box height. I'm also only able to install 8+1 group31 batteries, limiting my total AHr capacity.

I'd like to make the switch to LiFePO4, but insurance is proving to be a problem.  I had hoped by the time my current batteries failed I'd be able to find insurance...alas, they've gone belly up after only a few months.

I'd love to hear any thoughts about my current ( no pun intended) problem, 6v AGMs that will fit my space, Lithium conversion insurance availability (I'm US flagged, but could register elsewhere, I guess). 
-- 
Kent & Iris
KRISTY
SM243




 

Nick,

Interesting but consider charging that mixed bank.

I wonder how you can have mixed batteries and turn off charging to those in the mix that become fully charged and still charge the others in need of charging. I think it will cause the overcharging of some in the mixed bank and will melt them down.

Bill


CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Mon, Dec 13, 2021 at 10:25 AM Nick Newington via groups.io <ngtnewington=aol.com@groups.io> wrote:
I am going to throw this one out there to the community. it is just an idea...

Has anyone tried a hybrid AGM and Lithium battery bank?

I am thinking it to be 75% AGM and 25% Lithium. All connected together as one bank….I know…..just hear me out…..it is unorthodox and only an idea….up for debate...

Both battery types can be charged at  14v….then when the charge source is turned off

AGM's will drop to about 13.2v, immediately. This is the float voltage for AGM’s.

Lithium will also drop to 13.2v but maintain that voltage until say 20% capacity remains. This is part of the Lithium chemistry.

In a typical cycle, the AGM’s will be kept at float by the Lithium. So only the Lithium part will be used, but there will still be the AGM that can start to share the load after the Lithium bank has been 80% depleted. So in effect one is cycling only the Lithium part…given that Lithium can be cycled many more times than AGM’s this should be cost effective.

In Practice… imagine 8 AGM batteries of 12v 100AH  giving 400AH at 24v.  Normally this would be a typical bank. Cycle down to 75% each night. Thus consuming 100A. 

Now add two Lithiums of also 100AH 12v giving 100AH at 24v. You now have a 500AH bank….

If you still use 100A then the first 80 will come from the Lithiums or until their voltage drops below 13.2v and then the remaining demand will be supplied from the whole bank. in fact as the lithium voltage drops the AGM’s will take over and start to prop up the Lithiums…so that they do not get depleted too low.

When it comes to charging the Lithiums are more efficient and will accept fast charge, and the AGM’s will trickle full all day if there is sufficient solar….

The end result is that for the cost of only two Lithiums you have in effect a very long lasting bank. The AGM’s only cycle a few percent each day but on occasion they can be as required. They are there as reserve and barely cycle thus will last for a long time maybe more than a decade…

If one was to do this one would have to be very careful connecting the Lithiums… the AGM bank would need to be charged to float 13.2v. The Lithiums would need to be discharged to the same voltage 13.2v so when you connect them together there is no current flow between the batteries. It would be dangerous to connect them with say Lithiums at 13.8v and the AGM’s at 12.5v as it would arc at the moment of contact.

Now shout me down and tell my why this is not a good idea….

Remember the objective is to get the best AH for the lowest cost….

Merry Christmas

Nick

S/Y Amelia
AML 54-019

Stored ashore in Leros






On 12 Dec 2021, at 22:17, CW Bill Rouse <brouse@...> wrote:

Kent, Doesn't this explain the furling and outhaul motors not working properly?

Batteries are like anchors, there are lots of opinions and most opinions are based on limited comparative experience.

This is what I tell my clients and it is totally my opinion:
The best house battery buy is the basic DEKA Marine Master Deep Cycle DC31DT battery which will last 2 years, maybe 3. At $107 each (Lowes in the US) it seems like a bargain regardless of which battery you compare it to. Sure there are better batteries that will last longer, but none will cost you less per month. There are so many disappointments that have been reported by Amel owners, it is hard to choose something else. But when you buy these DEKAs and they fail in 2 years, remember that was the expectation. 

And don't forget about the DEKA 12-Volt 1000-Amp Marine Start Battery.

This is what 8 DC31DT batteries and 1 DEKA 12-Volt 1000-Amp Marine Start Battery will cost you at Lowes. 

Don't forget to check the water in these batteries. They will not last if you allow them to charge and discharge with low water.

<67774066-f4dd-4bf7-9da3-bba60d865215.png>




CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
  
View My Training Calendar

On Sun, Dec 12, 2021 at 11:36 AM karkauai via groups.io <karkauai=yahoo.com@groups.io> wrote:
Here I am again, singing the same tune...
In 2018 I bought 8 Crown "deep cycle" group 31s. They were great for about a year, then slowly began to deteriorate.  With 520 AHr and fully solar charged by early afternoon, when new I was waking up to 25.4-25.6v after about 50AHr use overnight.  This slowly deteriorated until I was running the generator before bed to avoid dropping voltage below 24.7.  I nursed them along until July 21 and bought 8 NAPA (Penn)105 AHr group 31s.  They have already failed, after working great initially, in just 5 months.

I charge at 28.5v Abs, 27v Float, and equalize at 31v (on recommendation of Crown engineer).  I have a 105A Magnum  charger/inverter, and 850W solar in 3 pairs, each pair with it's own Victron MPPP controller, and a 60 A alternator using a Balmar external regulator.

My first 3 sets of similar hybrid batteries didn't start to deteriorate until they were 30-36 months old.  This started after I installed solar.  Watching the voltages and solar output closely shows them acting as they are set to act.  Measuring amperage at the primary 25v cable from battery studs to switch, I don't find any excess current flowing with switches on or off.  All batteries measure within 0.1v after disconnecting for 6 hours. All cells have SG 1.019 +/- .001, which does not improve after 6 hrs equalizing at 31v.  All read within .2v of each other after load testing, which shows them barely in the "fair" range.  It doesn't seem to be a matter of one bad battery or cell, or unequal charging...they are all deteriorating at the same rate.

Soooo...
I need new batteries again, and am thinking about AGM golf cart batteries.  So far they are all 11.5" height, and my very early SM2000 has only 10.5" battery box height. I'm also only able to install 8+1 group31 batteries, limiting my total AHr capacity.

I'd like to make the switch to LiFePO4, but insurance is proving to be a problem.  I had hoped by the time my current batteries failed I'd be able to find insurance...alas, they've gone belly up after only a few months.

I'd love to hear any thoughts about my current ( no pun intended) problem, 6v AGMs that will fit my space, Lithium conversion insurance availability (I'm US flagged, but could register elsewhere, I guess). 
-- 
Kent & Iris
KRISTY
SM243




Mohammad Shirloo
 

HI Nick;

 

I like your out of the box thinking.

 

We think about batteries in very simplified terms. Voltage, current, charge and discharge rates, etc. However, batteries are more complex and one of the reasons they have not been able to be reduced to simple performance, maintenance and reliability that we can all count on, if a certain set of procedures are implemented. There are chemical reactions in play that are kept in check by the many control systems we employ. Sometimes even these safety items are insufficient to prevent unforeseen reactions.

 

I think the variables and potential downsides that get thrown in by combining such different chemistries, far outweigh any potential gain.

 

Happy Sailing;

 

 

Mohammad and Aty

B&B Kokomo

AMEL 54 #099

 

From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of Nick Newington via groups.io
Sent: Monday, December 13, 2021 8:25 AM
To: main@amelyachtowners.groups.io
Subject: Re: [AmelYachtOwners] SM Batteries

 

I am going to throw this one out there to the community. it is just an idea...

 

Has anyone tried a hybrid AGM and Lithium battery bank?

 

I am thinking it to be 75% AGM and 25% Lithium. All connected together as one bank….I know…..just hear me out…..it is unorthodox and only an idea….up for debate...

 

Both battery types can be charged at  14v….then when the charge source is turned off

 

AGM's will drop to about 13.2v, immediately. This is the float voltage for AGM’s.

 

Lithium will also drop to 13.2v but maintain that voltage until say 20% capacity remains. This is part of the Lithium chemistry.

 

In a typical cycle, the AGM’s will be kept at float by the Lithium. So only the Lithium part will be used, but there will still be the AGM that can start to share the load after the Lithium bank has been 80% depleted. So in effect one is cycling only the Lithium part…given that Lithium can be cycled many more times than AGM’s this should be cost effective.

 

In Practice… imagine 8 AGM batteries of 12v 100AH  giving 400AH at 24v.  Normally this would be a typical bank. Cycle down to 75% each night. Thus consuming 100A. 

 

Now add two Lithiums of also 100AH 12v giving 100AH at 24v. You now have a 500AH bank….

 

If you still use 100A then the first 80 will come from the Lithiums or until their voltage drops below 13.2v and then the remaining demand will be supplied from the whole bank. in fact as the lithium voltage drops the AGM’s will take over and start to prop up the Lithiums…so that they do not get depleted too low.

 

When it comes to charging the Lithiums are more efficient and will accept fast charge, and the AGM’s will trickle full all day if there is sufficient solar….

 

The end result is that for the cost of only two Lithiums you have in effect a very long lasting bank. The AGM’s only cycle a few percent each day but on occasion they can be as required. They are there as reserve and barely cycle thus will last for a long time maybe more than a decade…

 

If one was to do this one would have to be very careful connecting the Lithiums… the AGM bank would need to be charged to float 13.2v. The Lithiums would need to be discharged to the same voltage 13.2v so when you connect them together there is no current flow between the batteries. It would be dangerous to connect them with say Lithiums at 13.8v and the AGM’s at 12.5v as it would arc at the moment of contact.

 

Now shout me down and tell my why this is not a good idea….

 

Remember the objective is to get the best AH for the lowest cost….

 

Merry Christmas

 

Nick

 

S/Y Amelia

AML 54-019

 

Stored ashore in Leros

 

 

 

 

 



On 12 Dec 2021, at 22:17, CW Bill Rouse <brouse@...> wrote:

 

Kent, Doesn't this explain the furling and outhaul motors not working properly?

 

Batteries are like anchors, there are lots of opinions and most opinions are based on limited comparative experience.

 

This is what I tell my clients and it is totally my opinion:

The best house battery buy is the basic DEKA Marine Master Deep Cycle DC31DT battery which will last 2 years, maybe 3. At $107 each (Lowes in the US) it seems like a bargain regardless of which battery you compare it to. Sure there are better batteries that will last longer, but none will cost you less per month. There are so many disappointments that have been reported by Amel owners, it is hard to choose something else. But when you buy these DEKAs and they fail in 2 years, remember that was the expectation. 

 

And don't forget about the DEKA 12-Volt 1000-Amp Marine Start Battery.

 

This is what 8 DC31DT batteries and 1 DEKA 12-Volt 1000-Amp Marine Start Battery will cost you at Lowes. 

 

Don't forget to check the water in these batteries. They will not last if you allow them to charge and discharge with low water.

 

<67774066-f4dd-4bf7-9da3-bba60d865215.png>

 

 



CW Bill Rouse Amel Owners Yacht School

Address: 720 Winnie, Galveston Island, Texas 77550 

  

 

View My Training Calendar

 

On Sun, Dec 12, 2021 at 11:36 AM karkauai via groups.io <karkauai=yahoo.com@groups.io> wrote:

Here I am again, singing the same tune...
In 2018 I bought 8 Crown "deep cycle" group 31s. They were great for about a year, then slowly began to deteriorate.  With 520 AHr and fully solar charged by early afternoon, when new I was waking up to 25.4-25.6v after about 50AHr use overnight.  This slowly deteriorated until I was running the generator before bed to avoid dropping voltage below 24.7.  I nursed them along until July 21 and bought 8 NAPA (Penn)105 AHr group 31s.  They have already failed, after working great initially, in just 5 months.

I charge at 28.5v Abs, 27v Float, and equalize at 31v (on recommendation of Crown engineer).  I have a 105A Magnum  charger/inverter, and 850W solar in 3 pairs, each pair with it's own Victron MPPP controller, and a 60 A alternator using a Balmar external regulator.

My first 3 sets of similar hybrid batteries didn't start to deteriorate until they were 30-36 months old.  This started after I installed solar.  Watching the voltages and solar output closely shows them acting as they are set to act.  Measuring amperage at the primary 25v cable from battery studs to switch, I don't find any excess current flowing with switches on or off.  All batteries measure within 0.1v after disconnecting for 6 hours. All cells have SG 1.019 +/- .001, which does not improve after 6 hrs equalizing at 31v.  All read within .2v of each other after load testing, which shows them barely in the "fair" range.  It doesn't seem to be a matter of one bad battery or cell, or unequal charging...they are all deteriorating at the same rate.

Soooo...
I need new batteries again, and am thinking about AGM golf cart batteries.  So far they are all 11.5" height, and my very early SM2000 has only 10.5" battery box height. I'm also only able to install 8+1 group31 batteries, limiting my total AHr capacity.

I'd like to make the switch to LiFePO4, but insurance is proving to be a problem.  I had hoped by the time my current batteries failed I'd be able to find insurance...alas, they've gone belly up after only a few months.

I'd love to hear any thoughts about my current ( no pun intended) problem, 6v AGMs that will fit my space, Lithium conversion insurance availability (I'm US flagged, but could register elsewhere, I guess). 
-- 
Kent & Iris

KRISTY

SM243

 

 

 


Stefan Jeukendrup
 

Hi Nick,

That certainl has big advantages.
More people out there thinking along the same line.
Food for further reading:

https://batterybalance.com/

https://www.taoperf.com/category/tao-bms/

https://www.zwerfcat.nl/en/open-hybrid-bms.html

But it is still complex and every time I look at it new limitations/possiblities/safety aspects appear..
So not there yet with the "right" design for  a 24V 500A 600Ah custom hybrid? BMS  for a liveonboard cruising yacht.



Stefan Jeukendrup
sv Malaka Queen
SM2k #348 @ Newry Norther Ireland






Op 13 dec. 2021 16:25 schreef "Nick Newington via groups.io" <ngtnewington@...>:

I am going to throw this one out there to the community. it is just an idea...

Has anyone tried a hybrid AGM and Lithium battery bank?

I am thinking it to be 75% AGM and 25% Lithium. All connected together as one bank….I know…..just hear me out…..it is unorthodox and only an idea….up for debate...

Both battery types can be charged at  14v….then when the charge source is turned off

AGM's will drop to about 13.2v, immediately. This is the float voltage for AGM’s.

Lithium will also drop to 13.2v but maintain that voltage until say 20% capacity remains. This is part of the Lithium chemistry.

In a typical cycle, the AGM’s will be kept at float by the Lithium. So only the Lithium part will be used, but there will still be the AGM that can start to share the load after the Lithium bank has been 80% depleted. So in effect one is cycling only the Lithium part…given that Lithium can be cycled many more times than AGM’s this should be cost effective.

In Practice… imagine 8 AGM batteries of 12v 100AH  giving 400AH at 24v.  Normally this would be a typical bank. Cycle down to 75% each night. Thus consuming 100A. 

Now add two Lithiums of also 100AH 12v giving 100AH at 24v. You now have a 500AH bank….

If you still use 100A then the first 80 will come from the Lithiums or until their voltage drops below 13.2v and then the remaining demand will be supplied from the whole bank. in fact as the lithium voltage drops the AGM’s will take over and start to prop up the Lithiums…so that they do not get depleted too low.

When it comes to charging the Lithiums are more efficient and will accept fast charge, and the AGM’s will trickle full all day if there is sufficient solar….

The end result is that for the cost of only two Lithiums you have in effect a very long lasting bank. The AGM’s only cycle a few percent each day but on occasion they can be as required. They are there as reserve and barely cycle thus will last for a long time maybe more than a decade…

If one was to do this one would have to be very careful connecting the Lithiums… the AGM bank would need to be charged to float 13.2v. The Lithiums would need to be discharged to the same voltage 13.2v so when you connect them together there is no current flow between the batteries. It would be dangerous to connect them with say Lithiums at 13.8v and the AGM’s at 12.5v as it would arc at the moment of contact.

Now shout me down and tell my why this is not a good idea….

Remember the objective is to get the best AH for the lowest cost….

Merry Christmas

Nick

S/Y Amelia
AML 54-019

Stored ashore in Leros






On 12 Dec 2021, at 22:17, CW Bill Rouse <brouse@...> wrote:

Kent, Doesn't this explain the furling and outhaul motors not working properly?

Batteries are like anchors, there are lots of opinions and most opinions are based on limited comparative experience.

This is what I tell my clients and it is totally my opinion:
The best house battery buy is the basic DEKA Marine Master Deep Cycle DC31DT battery which will last 2 years, maybe 3. At $107 each (Lowes in the US) it seems like a bargain regardless of which battery you compare it to. Sure there are better batteries that will last longer, but none will cost you less per month. There are so many disappointments that have been reported by Amel owners, it is hard to choose something else. But when you buy these DEKAs and they fail in 2 years, remember that was the expectation. 

And don't forget about the DEKA 12-Volt 1000-Amp Marine Start Battery.

This is what 8 DC31DT batteries and 1 DEKA 12-Volt 1000-Amp Marine Start Battery will cost you at Lowes. 

Don't forget to check the water in these batteries. They will not last if you allow them to charge and discharge with low water.

<67774066-f4dd-4bf7-9da3-bba60d865215.png>




CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
  
View My Training Calendar

On Sun, Dec 12, 2021 at 11:36 AM karkauai via groups.io <karkauai=yahoo.com@groups.io> wrote:
Here I am again, singing the same tune...
In 2018 I bought 8 Crown "deep cycle" group 31s. They were great for about a year, then slowly began to deteriorate.  With 520 AHr and fully solar charged by early afternoon, when new I was waking up to 25.4-25.6v after about 50AHr use overnight.  This slowly deteriorated until I was running the generator before bed to avoid dropping voltage below 24.7.  I nursed them along until July 21 and bought 8 NAPA (Penn)105 AHr group 31s.  They have already failed, after working great initially, in just 5 months.

I charge at 28.5v Abs, 27v Float, and equalize at 31v (on recommendation of Crown engineer).  I have a 105A Magnum  charger/inverter, and 850W solar in 3 pairs, each pair with it's own Victron MPPP controller, and a 60 A alternator using a Balmar external regulator.

My first 3 sets of similar hybrid batteries didn't start to deteriorate until they were 30-36 months old.  This started after I installed solar.  Watching the voltages and solar output closely shows them acting as they are set to act.  Measuring amperage at the primary 25v cable from battery studs to switch, I don't find any excess current flowing with switches on or off.  All batteries measure within 0.1v after disconnecting for 6 hours. All cells have SG 1.019 +/- .001, which does not improve after 6 hrs equalizing at 31v.  All read within .2v of each other after load testing, which shows them barely in the "fair" range.  It doesn't seem to be a matter of one bad battery or cell, or unequal charging...they are all deteriorating at the same rate.

Soooo...
I need new batteries again, and am thinking about AGM golf cart batteries.  So far they are all 11.5" height, and my very early SM2000 has only 10.5" battery box height. I'm also only able to install 8+1 group31 batteries, limiting my total AHr capacity.

I'd like to make the switch to LiFePO4, but insurance is proving to be a problem.  I had hoped by the time my current batteries failed I'd be able to find insurance...alas, they've gone belly up after only a few months.

I'd love to hear any thoughts about my current ( no pun intended) problem, 6v AGMs that will fit my space, Lithium conversion insurance availability (I'm US flagged, but could register elsewhere, I guess). 
-- 
Kent & Iris
KRISTY
SM243





Marty Crighton
 

Nick,
When we were looking for solar panels in Grenada two months ago we ran into a Solar installation specialist who was experimenting with this idea you on his boat. He said he had built a hybrid bank and been using it on his boat for over 3 months. His bank was 12 volts. He admitted 3 months wasn't long enough to project long term reliability, but said he was realizing all the traits you lay out and was confident it was going to be an installation option he was going to be able to recommend to customers once he had enough data.  
Respectfully,
Marty

SV Nada, SM327
Puerto Rico


On Mon, Dec 13, 2021, 12:25 Nick Newington via groups.io <ngtnewington=aol.com@groups.io> wrote:
I am going to throw this one out there to the community. it is just an idea...

Has anyone tried a hybrid AGM and Lithium battery bank?

I am thinking it to be 75% AGM and 25% Lithium. All connected together as one bank….I know…..just hear me out…..it is unorthodox and only an idea….up for debate...

Both battery types can be charged at  14v….then when the charge source is turned off

AGM's will drop to about 13.2v, immediately. This is the float voltage for AGM’s.

Lithium will also drop to 13.2v but maintain that voltage until say 20% capacity remains. This is part of the Lithium chemistry.

In a typical cycle, the AGM’s will be kept at float by the Lithium. So only the Lithium part will be used, but there will still be the AGM that can start to share the load after the Lithium bank has been 80% depleted. So in effect one is cycling only the Lithium part…given that Lithium can be cycled many more times than AGM’s this should be cost effective.

In Practice… imagine 8 AGM batteries of 12v 100AH  giving 400AH at 24v.  Normally this would be a typical bank. Cycle down to 75% each night. Thus consuming 100A. 

Now add two Lithiums of also 100AH 12v giving 100AH at 24v. You now have a 500AH bank….

If you still use 100A then the first 80 will come from the Lithiums or until their voltage drops below 13.2v and then the remaining demand will be supplied from the whole bank. in fact as the lithium voltage drops the AGM’s will take over and start to prop up the Lithiums…so that they do not get depleted too low.

When it comes to charging the Lithiums are more efficient and will accept fast charge, and the AGM’s will trickle full all day if there is sufficient solar….

The end result is that for the cost of only two Lithiums you have in effect a very long lasting bank. The AGM’s only cycle a few percent each day but on occasion they can be as required. They are there as reserve and barely cycle thus will last for a long time maybe more than a decade…

If one was to do this one would have to be very careful connecting the Lithiums… the AGM bank would need to be charged to float 13.2v. The Lithiums would need to be discharged to the same voltage 13.2v so when you connect them together there is no current flow between the batteries. It would be dangerous to connect them with say Lithiums at 13.8v and the AGM’s at 12.5v as it would arc at the moment of contact.

Now shout me down and tell my why this is not a good idea….

Remember the objective is to get the best AH for the lowest cost….

Merry Christmas

Nick

S/Y Amelia
AML 54-019

Stored ashore in Leros






On 12 Dec 2021, at 22:17, CW Bill Rouse <brouse@...> wrote:

Kent, Doesn't this explain the furling and outhaul motors not working properly?

Batteries are like anchors, there are lots of opinions and most opinions are based on limited comparative experience.

This is what I tell my clients and it is totally my opinion:
The best house battery buy is the basic DEKA Marine Master Deep Cycle DC31DT battery which will last 2 years, maybe 3. At $107 each (Lowes in the US) it seems like a bargain regardless of which battery you compare it to. Sure there are better batteries that will last longer, but none will cost you less per month. There are so many disappointments that have been reported by Amel owners, it is hard to choose something else. But when you buy these DEKAs and they fail in 2 years, remember that was the expectation. 

And don't forget about the DEKA 12-Volt 1000-Amp Marine Start Battery.

This is what 8 DC31DT batteries and 1 DEKA 12-Volt 1000-Amp Marine Start Battery will cost you at Lowes. 

Don't forget to check the water in these batteries. They will not last if you allow them to charge and discharge with low water.

<67774066-f4dd-4bf7-9da3-bba60d865215.png>




CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
  
View My Training Calendar

On Sun, Dec 12, 2021 at 11:36 AM karkauai via groups.io <karkauai=yahoo.com@groups.io> wrote:
Here I am again, singing the same tune...
In 2018 I bought 8 Crown "deep cycle" group 31s. They were great for about a year, then slowly began to deteriorate.  With 520 AHr and fully solar charged by early afternoon, when new I was waking up to 25.4-25.6v after about 50AHr use overnight.  This slowly deteriorated until I was running the generator before bed to avoid dropping voltage below 24.7.  I nursed them along until July 21 and bought 8 NAPA (Penn)105 AHr group 31s.  They have already failed, after working great initially, in just 5 months.

I charge at 28.5v Abs, 27v Float, and equalize at 31v (on recommendation of Crown engineer).  I have a 105A Magnum  charger/inverter, and 850W solar in 3 pairs, each pair with it's own Victron MPPP controller, and a 60 A alternator using a Balmar external regulator.

My first 3 sets of similar hybrid batteries didn't start to deteriorate until they were 30-36 months old.  This started after I installed solar.  Watching the voltages and solar output closely shows them acting as they are set to act.  Measuring amperage at the primary 25v cable from battery studs to switch, I don't find any excess current flowing with switches on or off.  All batteries measure within 0.1v after disconnecting for 6 hours. All cells have SG 1.019 +/- .001, which does not improve after 6 hrs equalizing at 31v.  All read within .2v of each other after load testing, which shows them barely in the "fair" range.  It doesn't seem to be a matter of one bad battery or cell, or unequal charging...they are all deteriorating at the same rate.

Soooo...
I need new batteries again, and am thinking about AGM golf cart batteries.  So far they are all 11.5" height, and my very early SM2000 has only 10.5" battery box height. I'm also only able to install 8+1 group31 batteries, limiting my total AHr capacity.

I'd like to make the switch to LiFePO4, but insurance is proving to be a problem.  I had hoped by the time my current batteries failed I'd be able to find insurance...alas, they've gone belly up after only a few months.

I'd love to hear any thoughts about my current ( no pun intended) problem, 6v AGMs that will fit my space, Lithium conversion insurance availability (I'm US flagged, but could register elsewhere, I guess). 
-- 
Kent & Iris
KRISTY
SM243




--
Marty and Angela Crighton
Future Amel Owners
Pyeongtaek, South Korea


Jérémy
 

If you're interesting in this subject, you should check this very interesting video about mixing Lead / Lithium batteries : https://www.youtube.com/watch?v=XAOhT2HwKWM

Yet, I think it adds complexity, and I'm worry how it would perform in a long time range.


Jérémy
SM#121
Le 13/12/2021 à 17:25, Nick Newington via groups.io a écrit :

I am going to throw this one out there to the community. it is just an idea...

Has anyone tried a hybrid AGM and Lithium battery bank?

I am thinking it to be 75% AGM and 25% Lithium. All connected together as one bank….I know…..just hear me out…..it is unorthodox and only an idea….up for debate...

Both battery types can be charged at  14v….then when the charge source is turned off

AGM's will drop to about 13.2v, immediately. This is the float voltage for AGM’s.

Lithium will also drop to 13.2v but maintain that voltage until say 20% capacity remains. This is part of the Lithium chemistry.

In a typical cycle, the AGM’s will be kept at float by the Lithium. So only the Lithium part will be used, but there will still be the AGM that can start to share the load after the Lithium bank has been 80% depleted. So in effect one is cycling only the Lithium part…given that Lithium can be cycled many more times than AGM’s this should be cost effective.

In Practice… imagine 8 AGM batteries of 12v 100AH  giving 400AH at 24v.  Normally this would be a typical bank. Cycle down to 75% each night. Thus consuming 100A. 

Now add two Lithiums of also 100AH 12v giving 100AH at 24v. You now have a 500AH bank….

If you still use 100A then the first 80 will come from the Lithiums or until their voltage drops below 13.2v and then the remaining demand will be supplied from the whole bank. in fact as the lithium voltage drops the AGM’s will take over and start to prop up the Lithiums…so that they do not get depleted too low.

When it comes to charging the Lithiums are more efficient and will accept fast charge, and the AGM’s will trickle full all day if there is sufficient solar….

The end result is that for the cost of only two Lithiums you have in effect a very long lasting bank. The AGM’s only cycle a few percent each day but on occasion they can be as required. They are there as reserve and barely cycle thus will last for a long time maybe more than a decade…

If one was to do this one would have to be very careful connecting the Lithiums… the AGM bank would need to be charged to float 13.2v. The Lithiums would need to be discharged to the same voltage 13.2v so when you connect them together there is no current flow between the batteries. It would be dangerous to connect them with say Lithiums at 13.8v and the AGM’s at 12.5v as it would arc at the moment of contact.

Now shout me down and tell my why this is not a good idea….

Remember the objective is to get the best AH for the lowest cost….

Merry Christmas

Nick

S/Y Amelia
AML 54-019

Stored ashore in Leros






On 12 Dec 2021, at 22:17, CW Bill Rouse <brouse@...> wrote:

Kent, Doesn't this explain the furling and outhaul motors not working properly?

Batteries are like anchors, there are lots of opinions and most opinions are based on limited comparative experience.

This is what I tell my clients and it is totally my opinion:
The best house battery buy is the basic DEKA Marine Master Deep Cycle DC31DT battery which will last 2 years, maybe 3. At $107 each (Lowes in the US) it seems like a bargain regardless of which battery you compare it to. Sure there are better batteries that will last longer, but none will cost you less per month. There are so many disappointments that have been reported by Amel owners, it is hard to choose something else. But when you buy these DEKAs and they fail in 2 years, remember that was the expectation. 

And don't forget about the DEKA 12-Volt 1000-Amp Marine Start Battery.

This is what 8 DC31DT batteries and 1 DEKA 12-Volt 1000-Amp Marine Start Battery will cost you at Lowes. 

Don't forget to check the water in these batteries. They will not last if you allow them to charge and discharge with low water.

<67774066-f4dd-4bf7-9da3-bba60d865215.png>




CW Bill Rouse Amel Owners Yacht School

Address: 720 Winnie, Galveston Island, Texas 77550 
  

View My Training Calendar

On Sun, Dec 12, 2021 at 11:36 AM karkauai via groups.io <karkauai=yahoo.com@groups.io> wrote:
Here I am again, singing the same tune...
In 2018 I bought 8 Crown "deep cycle" group 31s. They were great for about a year, then slowly began to deteriorate.  With 520 AHr and fully solar charged by early afternoon, when new I was waking up to 25.4-25.6v after about 50AHr use overnight.  This slowly deteriorated until I was running the generator before bed to avoid dropping voltage below 24.7.  I nursed them along until July 21 and bought 8 NAPA (Penn)105 AHr group 31s.  They have already failed, after working great initially, in just 5 months.

I charge at 28.5v Abs, 27v Float, and equalize at 31v (on recommendation of Crown engineer).  I have a 105A Magnum  charger/inverter, and 850W solar in 3 pairs, each pair with it's own Victron MPPP controller, and a 60 A alternator using a Balmar external regulator.

My first 3 sets of similar hybrid batteries didn't start to deteriorate until they were 30-36 months old.  This started after I installed solar.  Watching the voltages and solar output closely shows them acting as they are set to act.  Measuring amperage at the primary 25v cable from battery studs to switch, I don't find any excess current flowing with switches on or off.  All batteries measure within 0.1v after disconnecting for 6 hours. All cells have SG 1.019 +/- .001, which does not improve after 6 hrs equalizing at 31v.  All read within .2v of each other after load testing, which shows them barely in the "fair" range.  It doesn't seem to be a matter of one bad battery or cell, or unequal charging...they are all deteriorating at the same rate.

Soooo...
I need new batteries again, and am thinking about AGM golf cart batteries.  So far they are all 11.5" height, and my very early SM2000 has only 10.5" battery box height. I'm also only able to install 8+1 group31 batteries, limiting my total AHr capacity.

I'd like to make the switch to LiFePO4, but insurance is proving to be a problem.  I had hoped by the time my current batteries failed I'd be able to find insurance...alas, they've gone belly up after only a few months.

I'd love to hear any thoughts about my current ( no pun intended) problem, 6v AGMs that will fit my space, Lithium conversion insurance availability (I'm US flagged, but could register elsewhere, I guess). 
-- 
Kent & Iris
KRISTY
SM243




--
SM #121 Nausicaä
Nantes, France


Arno Luijten
 

Hi Nick,

Before starting this experiment, bear in mind that Lithium batteries have dropped in price quite a bit lately. BattleBorn Lithium can be bought at 700 dollar for 12V/100Ah. On Amazon you'll find even much lower prices (down to approx $350). Some are badly build others are quite good build. Plenty of Youtubes around about these batteries.

Also keep in mind that most Lithium drop in replacements are only good for 100A discharge. So if you only have 2 units (12 or 24 V?) your bowthruster will push them into safety shutdown leaving the AGMs to pick up the slack. But if you go full Lithium you spread the load across all batteries and 4 units of 24 volt (so 8*12 or 4 * 24) will keep the system happy.

Cheers,

Arno Luijten
SV Luna


Nick Newington
 

Hi Jeremy, Arno


I just watched the video… very interesting.. sounds quite promising.

My problem with Lithium is that my current AGM bank is in perfect condition…also I leave the boat hauled out of the water for probably 60% of the time. With AGM I just leave them and the solar bank keeps them full….actually I think I may only change my solar panels from 2 X 256W to 2 X 375W. As we do not quite break even…. probably need an hour a day charging at least in October/early November when there is less sun in the Med. The new panels I am looking at are only 5cm longer and 1.5cm wider…so pretty much the same size but 50% more output….then I also have plans to sail to colder climes and worry that Lithium could be problematic….

I was just thinking, that Lithium will actually marry in just as the video linked below describes…For now I am not proposing to do anything, just thinking it through and consulting the oracle!

Sort of belt and braces philosophy. Maybe the hybrid solution is actually better, not just less expensive……I do not know…



Nick

Amelia

AML54-019
Leros



On 13 Dec 2021, at 18:07, Jérémy <jeremy@...> wrote:

If you're interesting in this subject, you should check this very interesting video about mixing Lead / Lithium batteries : https://www.youtube.com/watch?v=XAOhT2HwKWM

Yet, I think it adds complexity, and I'm worry how it would perform in a long time range.


Jérémy
SM#121
Le 13/12/2021 à 17:25, Nick Newington via groups.io a écrit :
I am going to throw this one out there to the community. it is just an idea...

Has anyone tried a hybrid AGM and Lithium battery bank?

I am thinking it to be 75% AGM and 25% Lithium. All connected together as one bank….I know…..just hear me out…..it is unorthodox and only an idea….up for debate...

Both battery types can be charged at  14v….then when the charge source is turned off

AGM's will drop to about 13.2v, immediately. This is the float voltage for AGM’s.

Lithium will also drop to 13.2v but maintain that voltage until say 20% capacity remains. This is part of the Lithium chemistry.

In a typical cycle, the AGM’s will be kept at float by the Lithium. So only the Lithium part will be used, but there will still be the AGM that can start to share the load after the Lithium bank has been 80% depleted. So in effect one is cycling only the Lithium part…given that Lithium can be cycled many more times than AGM’s this should be cost effective.

In Practice… imagine 8 AGM batteries of 12v 100AH  giving 400AH at 24v.  Normally this would be a typical bank. Cycle down to 75% each night. Thus consuming 100A. 

Now add two Lithiums of also 100AH 12v giving 100AH at 24v. You now have a 500AH bank….

If you still use 100A then the first 80 will come from the Lithiums or until their voltage drops below 13.2v and then the remaining demand will be supplied from the whole bank. in fact as the lithium voltage drops the AGM’s will take over and start to prop up the Lithiums…so that they do not get depleted too low.

When it comes to charging the Lithiums are more efficient and will accept fast charge, and the AGM’s will trickle full all day if there is sufficient solar….

The end result is that for the cost of only two Lithiums you have in effect a very long lasting bank. The AGM’s only cycle a few percent each day but on occasion they can be as required. They are there as reserve and barely cycle thus will last for a long time maybe more than a decade…

If one was to do this one would have to be very careful connecting the Lithiums… the AGM bank would need to be charged to float 13.2v. The Lithiums would need to be discharged to the same voltage 13.2v so when you connect them together there is no current flow between the batteries. It would be dangerous to connect them with say Lithiums at 13.8v and the AGM’s at 12.5v as it would arc at the moment of contact.

Now shout me down and tell my why this is not a good idea….

Remember the objective is to get the best AH for the lowest cost….

Merry Christmas

Nick

S/Y Amelia
AML 54-019

Stored ashore in Leros






On 12 Dec 2021, at 22:17, CW Bill Rouse <brouse@...> wrote:

Kent, Doesn't this explain the furling and outhaul motors not working properly?

Batteries are like anchors, there are lots of opinions and most opinions are based on limited comparative experience.

This is what I tell my clients and it is totally my opinion:
The best house battery buy is the basic DEKA Marine Master Deep Cycle DC31DT battery which will last 2 years, maybe 3. At $107 each (Lowes in the US) it seems like a bargain regardless of which battery you compare it to. Sure there are better batteries that will last longer, but none will cost you less per month. There are so many disappointments that have been reported by Amel owners, it is hard to choose something else. But when you buy these DEKAs and they fail in 2 years, remember that was the expectation. 

And don't forget about the DEKA 12-Volt 1000-Amp Marine Start Battery.

This is what 8 DC31DT batteries and 1 DEKA 12-Volt 1000-Amp Marine Start Battery will cost you at Lowes. 

Don't forget to check the water in these batteries. They will not last if you allow them to charge and discharge with low water.

<67774066-f4dd-4bf7-9da3-bba60d865215.png>




CW Bill Rouse Amel Owners Yacht School

Address: 720 Winnie, Galveston Island, Texas 77550 
  

View My Training Calendar

On Sun, Dec 12, 2021 at 11:36 AM karkauai via groups.io <karkauai=yahoo.com@groups.io> wrote:
Here I am again, singing the same tune...
In 2018 I bought 8 Crown "deep cycle" group 31s. They were great for about a year, then slowly began to deteriorate.  With 520 AHr and fully solar charged by early afternoon, when new I was waking up to 25.4-25.6v after about 50AHr use overnight.  This slowly deteriorated until I was running the generator before bed to avoid dropping voltage below 24.7.  I nursed them along until July 21 and bought 8 NAPA (Penn)105 AHr group 31s.  They have already failed, after working great initially, in just 5 months.

I charge at 28.5v Abs, 27v Float, and equalize at 31v (on recommendation of Crown engineer).  I have a 105A Magnum  charger/inverter, and 850W solar in 3 pairs, each pair with it's own Victron MPPP controller, and a 60 A alternator using a Balmar external regulator.

My first 3 sets of similar hybrid batteries didn't start to deteriorate until they were 30-36 months old.  This started after I installed solar.  Watching the voltages and solar output closely shows them acting as they are set to act.  Measuring amperage at the primary 25v cable from battery studs to switch, I don't find any excess current flowing with switches on or off.  All batteries measure within 0.1v after disconnecting for 6 hours. All cells have SG 1.019 +/- .001, which does not improve after 6 hrs equalizing at 31v.  All read within .2v of each other after load testing, which shows them barely in the "fair" range.  It doesn't seem to be a matter of one bad battery or cell, or unequal charging...they are all deteriorating at the same rate.

Soooo...
I need new batteries again, and am thinking about AGM golf cart batteries.  So far they are all 11.5" height, and my very early SM2000 has only 10.5" battery box height. I'm also only able to install 8+1 group31 batteries, limiting my total AHr capacity.

I'd like to make the switch to LiFePO4, but insurance is proving to be a problem.  I had hoped by the time my current batteries failed I'd be able to find insurance...alas, they've gone belly up after only a few months.

I'd love to hear any thoughts about my current ( no pun intended) problem, 6v AGMs that will fit my space, Lithium conversion insurance availability (I'm US flagged, but could register elsewhere, I guess). 
-- 
Kent & Iris
KRISTY
SM243




--
SM #121 Nausicaä
Nantes, France


karkauai
 


--Hi Bill,
The NAPA 8231Ns are the same battery EPenn sells as your DEKA DC31DTs.

I have tried furling with the generator while checking the voltage at the output of the controlling solenoids.  There is no significant voltage drop, with or without the generator/charger running.  I fully expected to see a significant drop, but it's not there.


Kent & Iris
KRISTY
SM243


Dean Gillies
 

Nick,
Yes. In 2020 I designed a directly connected AGM+LFP hybrid system almost exactly as you describe and proceeded to build a 12V version at home during Covid. I tested it thoroughly for 9 months.

Earlier this year, I installed the full 24V version on Stella and it has been running successfully for 6 months. I am extremely happy with the results.    

My design tilts the balance in favour of LFP capacity, using 115Ah of AGM and 540Ah of LFP.  This is simply because lithium likes to be cycled and lead likes to be floated.  In normal cruising, my AGM component is almost always on float at 100% SOC and my LFP component is almost always cycling between 30% and 90%.SOC. 

So why bother with the AGM's at all ?

1. If my BMS decides to disconnect my LFP component for any of the myriad reasons that can happen, then the AGM takes over the load seamlessly. The lights stay on, the instruments keep running and the coffee machine is still available (for a wee while anyway!).

2. If my alternator inhibit system was to fail while motoring and the LFP's were disconnected due to overcharging, the AGM batteries are still online and prevent any over-voltage damage to the 24V system components.

3. When laid up for long periods I can take the LFP component offline (at ~60%SOC) and simply operate the AGM in float either from the mains charger or shallow cycling from solar. I'm home again in Australia and Stella is in Spain so this is what I did before I left her.

Please feel free to email me if you want to talk turkey about the detailed design.
My battery box now likes the attached pics.

Cheers, Dean
SV STELLA 
A54-154

 



Martin Birkhoff
 

Hello Bill, 

sorry for my late response but I would like to add a different aspect to the discussion.

I'm sorry, but I have to disagree about your opinion concerning household batteries. If the batteries you name last 2 bi 3 years, they are not a convincing choice. According to my research they have a capacity of 225 Ah at 12 V for 107 USD. Currently an AGM Varta 115 Ah / 12 V costs about 280 € at SVB, Germany.
Looking at a battery bank of 600 - 700 Ah at 12 V, you can buy 3 Deka (675 Ah) or 6 Varta (690 Ah). The price difference is 321 USD to 1,580 €. But: the AGMs will last at least 6 to 7 years. So, arithmetically, this comes out to approximately the same amount of money. Against this background, there is no reason to buy classic lead-acid batteries. Another thing to consider: Such batteries are not designed for the characteristics on board a sailing boat, even if they are heavy-duty or deep-cycle batteries or whatever they may be called. 

From our personal experience: We started our circumnavigation 2004 to 2009 with gel batteries. After 7 years (!) of use, we had to replace them in Chile in early 2008 if my memory is correct. Since we couldn't get adequate batteries, we bought heavy-duty lead-acid batteries (maintenance-free). It soon became apparent that they were not suitable for the consumption or discharge characteristics on board a sailing boat on a long voyage and broke down after a few months. About nine months later (still in 2008) we bought AGM batteries of comparable capacity in Peru. These were on board our boat until 2020!  

To be honest, I never understood the reason why Amel still provided lead-acid batteries for the 54. This was not state of the art even 15 years ago. In addition, from my personal point of view as an environmental engineer, it is not a good idea to use batteries that have to be disposed of every two to three years. The goal should rather be to strive for the most sustainable use possible. In addition, there is what happens to the disposed lead-acid batteries in many countries. We have had extremely questionable experiences with this.

I ask for your understanding, but I simply have to put this up for discussion.
 
Best regards 

Martin
SY Mago del Sur - 54#40
currently Marina di Ragusa
 


Dean Gillies
 

Kent,
I haven't seen the spec sheets for your batteries, but... is it possible that your ABS voltage is a little low?

Solar is notorious for gradually undercharging lead batteries.  You might think your lead bank is fully charged by mid-day, but mostly that's not true.  Lead batteries have an incredibly long tail in the charging cycle and 8 hours of sun often isn't enough to give them a complete charge. 
 
Why does your battery monitor tell you they are fully charged?  
Usually the monitor uses a voltage threshold and a tail current to determine when 100% SOC is reached.  

If you are charging at a lower (Abs) voltage then the current will also be lower, and the monitor will declare 100% SOC sooner than the battery needs. If you were to then increase the voltage to say 29.4V then the current would increase and it would take much longer for the monitor to declare 100% SOC.  (The tail is very flat). So using a 28.5V (Abs) level may be declaring 100% earlier than it should be.  This problem will compound in quite a short time ... the battery charge acceptance rate will diminish, resulting in the tail current threshold happening incrementally sooner.  The batteries seem fully charged, according to the monitor, but in fact they are just losing capacity.

Didn't intend this post to be so long!  Bottom line, is your 28.5V Abs voltage the same as recommended by the battery manufacturer? (For example my AGM's specify 28.8V - 29.8V, so I use ABS 29.4V for cyclic use)

Cheers, Dean
SV STELLA
A54-154   


 

Martin,

Maybe you missed that the DKEA Size 31 Marine Master Batteries are $107 USD or 95 euro.

Additionally, it seems that the risk of ruining batteries by overcharging, etc., and other reasons is significant among Amel owners.


CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Mon, Dec 13, 2021 at 3:08 PM Martin Birkhoff <mbirkhoff@...> wrote:
Hello Bill, 

sorry for my late response but I would like to add a different aspect to the discussion.

I'm sorry, but I have to disagree about your opinion concerning household batteries. If the batteries you name last 2 bi 3 years, they are not a convincing choice. According to my research they have a capacity of 225 Ah at 12 V for 107 USD. Currently an AGM Varta 115 Ah / 12 V costs about 280 € at SVB, Germany.
Looking at a battery bank of 600 - 700 Ah at 12 V, you can buy 3 Deka (675 Ah) or 6 Varta (690 Ah). The price difference is 321 USD to 1,580 €. But: the AGMs will last at least 6 to 7 years. So, arithmetically, this comes out to approximately the same amount of money. Against this background, there is no reason to buy classic lead-acid batteries. Another thing to consider: Such batteries are not designed for the characteristics on board a sailing boat, even if they are heavy-duty or deep-cycle batteries or whatever they may be called. 

From our personal experience: We started our circumnavigation 2004 to 2009 with gel batteries. After 7 years (!) of use, we had to replace them in Chile in early 2008 if my memory is correct. Since we couldn't get adequate batteries, we bought heavy-duty lead-acid batteries (maintenance-free). It soon became apparent that they were not suitable for the consumption or discharge characteristics on board a sailing boat on a long voyage and broke down after a few months. About nine months later (still in 2008) we bought AGM batteries of comparable capacity in Peru. These were on board our boat until 2020!  

To be honest, I never understood the reason why Amel still provided lead-acid batteries for the 54. This was not state of the art even 15 years ago. In addition, from my personal point of view as an environmental engineer, it is not a good idea to use batteries that have to be disposed of every two to three years. The goal should rather be to strive for the most sustainable use possible. In addition, there is what happens to the disposed lead-acid batteries in many countries. We have had extremely questionable experiences with this.

I ask for your understanding, but I simply have to put this up for discussion.
 
Best regards 

Martin
SY Mago del Sur - 54#40
currently Marina di Ragusa