How much Solar?


Billy Newport
 

I dont know if this has been addressed before but besides an answer of as much as possible, what are peoples experiences? 
My 55 currently has 750W (2 × 375w LG) on the davitts. I am debating bumping this to 3 panels.

I dont have lithium and dont intend to do that ub
Neil my new GELs die, hopefully in 4 or 5 years.

I suspect 750W will be enough in a sunny location at anchor to avoid running the generator most days. Our boat drops from 100% to 70% overnight or about 200aH. So, at anchor, I figure just under 400aH a day or about 5kw. I dont know if that's high or now. Our boat is pretty stock as fitted.
If I'm moving then I will need to run the genset no matter what because of radar, auto pilot etc, I suspect. 
I'd appreciate other people's experience with Amels.

Billy
Amel 55#56


Mark McGovern
 

Billy,

This thread has some great "real world" solar data in it: https://amelyachtowners.groups.io/g/main/topic/32721714  

Pay particular attention to the posts by Scott from Tengah (Amel 54) and Porter of Ibis (also an Amel 54).

To summarize, Tengah has 960 Watts of solar and was able to average ~5400 Wh/day into it's house bank over the course of a month.  Note, Tengah has an LiFePo4 battery bank.  Ibis has a similar size solar array at 945 Watts but it has an AGM battery bank.  Porter doesn't give an exact amount of Wh/day put into his house bank but looking at the image he posted of his solar data, it appears to be less than half the amount that Tengah is able to put in.  The difference is mainly due to the significantly reduced charge acceptance rate of Lead Acid vs LFP batteries at higher SOCs.

So while adding a third solar panel will help, it won't likely eliminate the need for you to run the generator every day.  At least not until you change out your batteries from lead acid to something with a much higher charge acceptance rate at high states of charge.

--
Mark McGovern
SM #440 Cara
Deale, MD USA


Karen Smith
 

Billy,

Our usage is pretty consistent, an average of between 200 and 250 W while at anchor, and 325W or a bit more when underway.  This is with two chest freezers, and the front opening galley fridge which are the big usage hogs.  This is separate from the power needed for the water maker or laundry.  We have a smaller battery bank of 464 Amp-hrs, and the typical consumption we see over night is MUCH less than what you are seeing.  Typically, our SOC drops about 15 to 18% overnight, significantly less than 100 Amp-hrs.  Our typical overall usage while at anchor for 24 hours is about 180 to 200 Amp-hrs with about half this amount being supplied by our panels.  All those numbers shift a bit depending on weather and temperature.

Our solar panels rate out at about 630W, and we typically run the generator every other day.

Bill Kinney
SM160, Harmonie
Charleston, SC, USA


michael winand
 

We have 3 345w lg panels. In a good summer day we can see 7kw. Max watts peaks at 1150w to 1200w.
This is with Firefly batteries.  If they top off the batteries early in the morning I will switch on the water heater or 1 air-conditioning unit. 
We are very pleased with the solar system, genset hours are reduced by 70%.
Michael, Nebo sm251 


On Tue, 2 Feb 2021 at 1:49 am, Billy Newport
<billy@...> wrote:
I dont know if this has been addressed before but besides an answer of as much as possible, what are peoples experiences? 
My 55 currently has 750W (2 × 375w LG) on the davitts. I am debating bumping this to 3 panels.

I dont have lithium and dont intend to do that ub
Neil my new GELs die, hopefully in 4 or 5 years.

I suspect 750W will be enough in a sunny location at anchor to avoid running the generator most days. Our boat drops from 100% to 70% overnight or about 200aH. So, at anchor, I figure just under 400aH a day or about 5kw. I dont know if that's high or now. Our boat is pretty stock as fitted.
If I'm moving then I will need to run the genset no matter what because of radar, auto pilot etc, I suspect. 
I'd appreciate other people's experience with Amels.

Billy
Amel 55#56


Dan Carlson
 

Hello Billy, I just increased my solar to 2 @ 335w panels on a stern arch (670w total). In January in Antigua I'm averaging just under 3kw per day but it is increasing slightly as the days get longer. Location around the island impacts cloud cover! (Currently ranging from 2.5kW to 3.6KW)

We typically consume about 140AH (3.7KW) at anchor. So I have a daily deficit that ranges from 5AH to 40AH. 

I have 400 AH of LiFePo4, so I can now go extended time without running the genset. Basically I run the genset when I want to run the watermaker and then add 30-60amps of charging to load the generator up to about 19-21 amps and add some charge to the batteries.

This is so much better than when I was running the generator daily to keep the batteries charged.

The downside of my new situation is that I used to also keep the water heater hot with the daily generator runs. Now I need to rewire my 230v side so that I can periodically run the water heater from the inverter.

Hope that helps with and additional data point. 

Best regards, Daniel and Lori Carlson on sv BeBe, SM #387



On Mon, Feb 1, 2021, 11:49 AM Billy Newport <billy@...> wrote:
I dont know if this has been addressed before but besides an answer of as much as possible, what are peoples experiences? 
My 55 currently has 750W (2 × 375w LG) on the davitts. I am debating bumping this to 3 panels.

I dont have lithium and dont intend to do that ub
Neil my new GELs die, hopefully in 4 or 5 years.

I suspect 750W will be enough in a sunny location at anchor to avoid running the generator most days. Our boat drops from 100% to 70% overnight or about 200aH. So, at anchor, I figure just under 400aH a day or about 5kw. I dont know if that's high or now. Our boat is pretty stock as fitted.
If I'm moving then I will need to run the genset no matter what because of radar, auto pilot etc, I suspect. 
I'd appreciate other people's experience with Amels.

Billy
Amel 55#56


Justin Maguire
 

Has anyone experienced the 50 with the lithium? 

My new 50..  which because of covid I won’t set foot on until April 1 when she arrives in the US... has 800ah of 24v mastervolt lithium (which I could almost not believe). 

I’ve got the new gn-espace induction stove...

She currently has 600watts of solar on the davits, and 575 on the hard top... I could go up to 1000 on the davits by wanted to see if this setup would work before making the davits into a full blown flight deck 🤣

Anyway.. I’m dying to see what the real world usage will be and how often I’ll have to run the gen set... ideally this setup should provide for a very independent and luxurious setup but real world vs. theory are always different...

Anyone out there have the lithium on the 50 (or the 60 for that matter as it’s the same)?

Scott - your numbers make me sooper optimistic...

Aching to see my new baby in person...

Sv Fregata - amel50 #43



Cheers,
-Justin 



On Feb 1, 2021, at 16:44, Dan Carlson <carlsdan61@...> wrote:


Hello Billy, I just increased my solar to 2 @ 335w panels on a stern arch (670w total). In January in Antigua I'm averaging just under 3kw per day but it is increasing slightly as the days get longer. Location around the island impacts cloud cover! (Currently ranging from 2.5kW to 3.6KW)

We typically consume about 140AH (3.7KW) at anchor. So I have a daily deficit that ranges from 5AH to 40AH. 

I have 400 AH of LiFePo4, so I can now go extended time without running the genset. Basically I run the genset when I want to run the watermaker and then add 30-60amps of charging to load the generator up to about 19-21 amps and add some charge to the batteries.

This is so much better than when I was running the generator daily to keep the batteries charged.

The downside of my new situation is that I used to also keep the water heater hot with the daily generator runs. Now I need to rewire my 230v side so that I can periodically run the water heater from the inverter.

Hope that helps with and additional data point. 

Best regards, Daniel and Lori Carlson on sv BeBe, SM #387



On Mon, Feb 1, 2021, 11:49 AM Billy Newport <billy@...> wrote:
I dont know if this has been addressed before but besides an answer of as much as possible, what are peoples experiences? 
My 55 currently has 750W (2 × 375w LG) on the davitts. I am debating bumping this to 3 panels.

I dont have lithium and dont intend to do that ub
Neil my new GELs die, hopefully in 4 or 5 years.

I suspect 750W will be enough in a sunny location at anchor to avoid running the generator most days. Our boat drops from 100% to 70% overnight or about 200aH. So, at anchor, I figure just under 400aH a day or about 5kw. I dont know if that's high or now. Our boat is pretty stock as fitted.
If I'm moving then I will need to run the genset no matter what because of radar, auto pilot etc, I suspect. 
I'd appreciate other people's experience with Amels.

Billy
Amel 55#56


Chantal & Alain sv Makemo
 

Hello Billy,
we acquired 4 months ago Makemo, Amel 55 nº1 and we are experiencing all the fixtures.
today with one fridge and one freezer, we are consuming about 200Ah/day at the mooring and much more while sailing with everything on. We only have 2x 185w solar panels on our davitts producing in the West Indies between 1.2 and 1.5kwh in January (8am till 5pm more or less).
Therefore we are using the genset everyday min 2.5 h up to 4h.
We are looking for increasing our solar capacity replacing ours panels with 2x 370 or 440w new panels located at the  same place.
it should deliver 2x mini representing 2-3 of our consumption at the mooring.
our batteries are AGM 660Ah (24v).
we would also like to put flexi panels in the hard top but we have not yet identified a good way to put the cables.
Happy to exchange your project when defined.
regards


Justin Maguire
 

Congratulations on Makemo!

 

I had no idea that the generator run time was that much – wow! Solar and Lithium would transform your world for sure!

 

 

Sent from Mail for Windows 10

 

From: Chantal & Alain sv Makemo
Sent: Tuesday, February 2, 2021 12:50 PM
To: main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] How much Solar?

 

Hello Billy,
we acquired 4 months ago Makemo, Amel 55 nº1 and we are experiencing all the fixtures.
today with one fridge and one freezer, we are consuming about 200Ah/day at the mooring and much more while sailing with everything on. We only have 2x 185w solar panels on our davitts producing in the West Indies between 1.2 and 1.5kwh in January (8am till 5pm more or less).
Therefore we are using the genset everyday min 2.5 h up to 4h.
We are looking for increasing our solar capacity replacing ours panels with 2x 370 or 440w new panels located at the  same place.
it should deliver 2x mini representing 2-3 of our consumption at the mooring.
our batteries are AGM 660Ah (24v).
we would also like to put flexi panels in the hard top but we have not yet identified a good way to put the cables.
Happy to exchange your project when defined.
regards

 


Wolfgang Weber <webercardio@...>
 

Hello to the group,
We have 600Ah/24V wetcell batteries and no solar which is good for sailing the Med-sea.
The problem with this configuration is you start the onan and charger with 100-80 A and charging will decrease to 30-40 A after 1/2-1 .
So first step for me is to switch to 600Ah Lithium batteries before adding any solarcells.
Stay healthy!
Wolfgang Weber SY Elise Amel 54#162






Ken Powers SV Aquarius
 

Hello Billy,

Aquarius was fitted with 600W of hard panels, and we did pretty good for 3 years.  Then our Victron Batteries Started to go.  Once your batteries start to go, they take more energy to charge.  As they age it's like cutting your battery capacity in 1/2 as well as your solar capacity.  My video https://www.youtube.com/watch?v=BcWBiDnB794 about batteries is still relevent.

Remember not use your bow thruster too much, and when you do, turn on your genset with all the chargers going full blast.  But, you probably only have a 100A of charger, so you will be sucking 300A every time you push that joystick.  Sucking 300A out of your 400AH battery pack is not really good for them, and if you don't run your genset, you will be sucking 400A.   Just a note for all SM and A54 owners - the less you use your BowThruster the longer your Lead Batteries will last.

We just switched to LiFePO4 batteries.  They are better, and yes, cheaper than Lead.  Too man benefits to list here.   Now, I can run my AC in one cabin 3 or 4 hours a night without turning on the genset.  Now that is a game changer.  And, another cool thing, 400A is nothing for a 600AH bank of LiFePO4.  I bought my new batteries for under $4000.  There are a lot of people out there trying to scare you about LiFePO4 batteries.  In my opinion LiFePO4 is cheaper to buy, easier to maintain, and all the the scare tactics from those who what to make bigger profits, are just keeping to the sales strategy.   

For a 400AH bank of Gel, the cost is just over $3000.  They are rated for about 600 to 800 cycles, so if you're really good, they are going to last you 1200 cycles.  The LiFePO4 batteries are rated at 5000 cycles, so if I'm really bad I might see 2500 cycles.  Man, I don't know why anyone is buying Lead these days.

But, I will say there is one good thing about Lead Batteries on an SM.  Your SM will be weighted correctly, and it will tilt much less to port when you're running low on fuel.

All the Best,

Ken



Eric Opdeweegh
 

Ken,

Your video and arguments seem rock solid. In Holland we would say: "Daar is geen speld tussen te krijgen". Rough translation: Can't get a sewing-pin between those arguments :) 

Nothing is said however about extra ventilation. Did you install extra ventilation in the bank storage area? 

Thanks and Happy Sailing

Eric Opdeweegh
Future SM2K owner, hopefully very soon:)


Paul Osterberg
 

I just finalizing the installation of a 540 Ah LIFePO4 bank, have discharge att maximum what my Inverter can draw and charged with 100 A, I only notice minor temp increase, more heat from my 4 MPPT regulators. and more heat from the BMS when balancing, but that should be reduced by time. se no need for ventilation. So fare very happy with the LiFePO4 installation.
We had last year 810 W solar panel which gave about 125 Ah a normal sunny day in Portugal. Now I have 1400 w just installed got 70 Ah yesterday a very murky February day, started the solar charger at around 11 o clock. when I arrived at the boat. guess I will easy get 200Ah a day, enough for cocking
Paul on SY Kerpa SM#259


Scott SV Tengah
 

Hi everyone,

In FP and Hawaii, we were averaging 5500-6000wh per day. Most I've seen is a handful of days approaching 7000wh. As Mark mentioned, we have a lifepo4 bank (2.5 years now) and that makes a huge difference as you can see when you compare my data to Porter's with similar solar output and similar environmental conditions. I'm sure you all see that once you take a lead battery above 80%, the charge acceptance drops like a rock. And worse, you're supposed to keep lead at high SOC to prevent sulfation so a lot of your solar output will be wasted. With my bank, the full output of the solar (or the 200amps of AC-powered charging) is taken up by the batteries until the upper 90% SOC. And I try to keep the batteries between say 50-80% to maximize longevity, so literally every watt is being put into the batteries.

Another thing that Mark didn't mention, but makes a huge difference is that lifepo4 charging is much more efficient than lead charging. With lead, you lose about 20-30% of your the charge current through inefficiencies. read: heat. With lifepo4 over 2.5 years I'm losing about 2-3%, based on the cumulative data on kWh in compared to kWh out that is provided by my Victron MPPT.

Billy - I suspect something is wrong with your battery monitor? We have 450ah and with 2 fridges and a freezer running, we drop about 8% overnight or 36AH. Not sure if you have water cooled fridges on the 55, but the homemade Frankenstein brushless pump (detailed in another post) has reduced power consumption considerably. Freezer is colder, too! You also stated that you figure about 5kw a day, which should be 5000/25.6v = 195AH, which sounds more realistic. Or are you running other items that we're not? In any event, I don't think your 750w on gel will be enough to eliminate genset usage most days if you are anything like us. 2 fridges plus a freezer and computers on, electric kettle, microwave and plus, the admiral has gotten addicted to Ozark, so the TV is on quite a bit. :) That said, we also run the water maker off our batteries and the 2.2kw scuba compressor if the batteries get too full. But I still suspect 750w on gel won't be enough.

Dan - have you considered adding more AC-based charging capacity? If you have to run the genset, since you have lithium, which can accept high currents, might as well add as much charging capacity to reduce genset runtimes. Your calculated figures on $/hr for genset usage frightened me into looking at more solar! And it's not just the money, I am consciously trying to reduce ongoing maintenance. With our 200amps charging capacity, on the rare instances we run the genset, it's almost always for less than an hour. I suggest rewiring that water heater. We do, in fact, run the water heater on battery/inverter. Our heater is only 700w and I run it for say 20 minutes prior to each shower, which gives me just enough hot water for 2 people.

Eric - no need to add extra ventilation, at least on our passage berth mounted batteries. I have monitored individual battery temps via bluetooth and they rarely get above 30c. They only get hot (40c or so) when I'm running AC-based chargers at 200amps and try to take them to 90%+ in order to balance out the batteries and help the battery monitor reset.

Justin - do you have the hardtop panels on a separate MPPT? Once you get on your boat, I am really really curious to know how many AH you get out of them, compared to your aft panels. Another boat we met in FP has 2kw of solar on their decks and they produce about the same kWH per day as we do with only 960w of arch mounted solar. Much of that inefficiency is probably related to shading, but if you look at the specs on most panels, the power output drops about 0.3-0.5% PER degree C increase over 25degC. I measured the panel temps on mine and it's not much above ambient since they get cooled by the breeze blowing underneath them. I would love to add them but it would be a lot of brain damage for me, so I want to make sure it's worth the effort or maybe I just accept I'll have to run the genset every few weeks.  

Ken is very right with the weight balance issue! I am sick of scrubbing the port side gelcoat! 

At the end of the day, energy is like money - the more you have, the more you use!


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Justin Maguire
 

Scott –

 

The hard top panels are on a separate MPPT, and I definitely don’t expect them to perform to their “rating” per the heat challenge that all flush mounted panels have… the question will be just how much. As I mentioned, other Amel 50 owners have mounted up to a 1000w on the davits… I know I can eventually go to that but wanted to see what my real world performance was with 600 on the davits and the 575 on the roof… what I don’t know is if each panel on the rear has it’s own MPPT controller…

 

One thing I’m also trying to balance is needing to run the gen-set just enough to keep it happy… 😊

With the full induction galley (yay! No propane or waste heat), and an already power hungry boat like the Amel, I’m very curious to see how she plays out. Either way, your numbers give me hope.

 

I’m just over 2 years from quitting the job and pushing off, so I’ve got some time to sort out the boat, get to know her, and make any mods before then. I’ll get to spend 3 months this summer in new England cruising her (and working from her)… and then I’ll be shipping her back to the west coast (SFO – home is Sausalito)… once she’s back in the bay area I’ll have just over a year before leaving to make any final mods and set the last of my life in motion…

 

So much learning from all of you.

Thank you for your wisdom and example!

 


Cheers,

-Justin

 

 

 

 

Sent from Mail for Windows 10

 

From: Scott SV Tengah
Sent: Wednesday, February 3, 2021 9:23 PM
To: main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] How much Solar?

 

Hi everyone,

In FP and Hawaii, we were averaging 5500-6000wh per day. Most I've seen is a handful of days approaching 7000wh. As Mark mentioned, we have a lifepo4 bank (2.5 years now) and that makes a huge difference as you can see when you compare my data to Porter's with similar solar output and similar environmental conditions. I'm sure you all see that once you take a lead battery above 80%, the charge acceptance drops like a rock. And worse, you're supposed to keep lead at high SOC to prevent sulfation so a lot of your solar output will be wasted. With my bank, the full output of the solar (or the 200amps of AC-powered charging) is taken up by the batteries until the upper 90% SOC. And I try to keep the batteries between say 50-80% to maximize longevity, so literally every watt is being put into the batteries.

Another thing that Mark didn't mention, but makes a huge difference is that lifepo4 charging is much more efficient than lead charging. With lead, you lose about 20-30% of your the charge current through inefficiencies. read: heat. With lifepo4 over 2.5 years I'm losing about 2-3%, based on the cumulative data on kWh in compared to kWh out that is provided by my Victron MPPT.

Billy - I suspect something is wrong with your battery monitor? We have 450ah and with 2 fridges and a freezer running, we drop about 8% overnight or 36AH. Not sure if you have water cooled fridges on the 55, but the homemade Frankenstein brushless pump (detailed in another post) has reduced power consumption considerably. Freezer is colder, too! You also stated that you figure about 5kw a day, which should be 5000/25.6v = 195AH, which sounds more realistic. Or are you running other items that we're not? In any event, I don't think your 750w on gel will be enough to eliminate genset usage most days if you are anything like us. 2 fridges plus a freezer and computers on, electric kettle, microwave and plus, the admiral has gotten addicted to Ozark, so the TV is on quite a bit. :) That said, we also run the water maker off our batteries and the 2.2kw scuba compressor if the batteries get too full. But I still suspect 750w on gel won't be enough.

Dan - have you considered adding more AC-based charging capacity? If you have to run the genset, since you have lithium, which can accept high currents, might as well add as much charging capacity to reduce genset runtimes. Your calculated figures on $/hr for genset usage frightened me into looking at more solar! And it's not just the money, I am consciously trying to reduce ongoing maintenance. With our 200amps charging capacity, on the rare instances we run the genset, it's almost always for less than an hour. I suggest rewiring that water heater. We do, in fact, run the water heater on battery/inverter. Our heater is only 700w and I run it for say 20 minutes prior to each shower, which gives me just enough hot water for 2 people.

Eric - no need to add extra ventilation, at least on our passage berth mounted batteries. I have monitored individual battery temps via bluetooth and they rarely get above 30c. They only get hot (40c or so) when I'm running AC-based chargers at 200amps and try to take them to 90%+ in order to balance out the batteries and help the battery monitor reset.

Justin - do you have the hardtop panels on a separate MPPT? Once you get on your boat, I am really really curious to know how many AH you get out of them, compared to your aft panels. Another boat we met in FP has 2kw of solar on their decks and they produce about the same kWH per day as we do with only 960w of arch mounted solar. Much of that inefficiency is probably related to shading, but if you look at the specs on most panels, the power output drops about 0.3-0.5% PER degree C increase over 25degC. I measured the panel temps on mine and it's not much above ambient since they get cooled by the breeze blowing underneath them. I would love to add them but it would be a lot of brain damage for me, so I want to make sure it's worth the effort or maybe I just accept I'll have to run the genset every few weeks.  

Ken is very right with the weight balance issue! I am sick of scrubbing the port side gelcoat! 

At the end of the day, energy is like money - the more you have, the more you use!


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com

 


Scott SV Tengah
 

Justin,

We wired the arch panels in parallel to a junction box in the lazarette and then a pair of wires to one MPPT so theoretically they're more tolerant of partial shading. Ideally I have 3 MPPTs for the 3 panels but damn, that's a lot of wiring!

Do let us know how much relative power you get from the various panels. Even if our environmental conditions are different, the relative output should give us an idea of how effective surface mounted panels are vs. their output ratings. BTW - I am from the Bay Area, too, so I understand fog will have a bit of an impact on your output. :)

Good luck!

On Fri, Feb 5, 2021 at 6:00 AM Justin Maguire <justin_maguire@...> wrote:

Scott –

 

The hard top panels are on a separate MPPT, and I definitely don’t expect them to perform to their “rating” per the heat challenge that all flush mounted panels have… the question will be just how much. As I mentioned, other Amel 50 owners have mounted up to a 1000w on the davits… I know I can eventually go to that but wanted to see what my real world performance was with 600 on the davits and the 575 on the roof… what I don’t know is if each panel on the rear has it’s own MPPT controller…

 

One thing I’m also trying to balance is needing to run the gen-set just enough to keep it happy… 😊

With the full induction galley (yay! No propane or waste heat), and an already power hungry boat like the Amel, I’m very curious to see how she plays out. Either way, your numbers give me hope.

 

I’m just over 2 years from quitting the job and pushing off, so I’ve got some time to sort out the boat, get to know her, and make any mods before then. I’ll get to spend 3 months this summer in new England cruising her (and working from her)… and then I’ll be shipping her back to the west coast (SFO – home is Sausalito)… once she’s back in the bay area I’ll have just over a year before leaving to make any final mods and set the last of my life in motion…

 

So much learning from all of you.

Thank you for your wisdom and example!

 


Cheers,

-Justin

 

 

 

 

Sent from Mail for Windows 10

 

From: Scott SV Tengah
Sent: Wednesday, February 3, 2021 9:23 PM
To: main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] How much Solar?

 

Hi everyone,

In FP and Hawaii, we were averaging 5500-6000wh per day. Most I've seen is a handful of days approaching 7000wh. As Mark mentioned, we have a lifepo4 bank (2.5 years now) and that makes a huge difference as you can see when you compare my data to Porter's with similar solar output and similar environmental conditions. I'm sure you all see that once you take a lead battery above 80%, the charge acceptance drops like a rock. And worse, you're supposed to keep lead at high SOC to prevent sulfation so a lot of your solar output will be wasted. With my bank, the full output of the solar (or the 200amps of AC-powered charging) is taken up by the batteries until the upper 90% SOC. And I try to keep the batteries between say 50-80% to maximize longevity, so literally every watt is being put into the batteries.

Another thing that Mark didn't mention, but makes a huge difference is that lifepo4 charging is much more efficient than lead charging. With lead, you lose about 20-30% of your the charge current through inefficiencies. read: heat. With lifepo4 over 2.5 years I'm losing about 2-3%, based on the cumulative data on kWh in compared to kWh out that is provided by my Victron MPPT.

Billy - I suspect something is wrong with your battery monitor? We have 450ah and with 2 fridges and a freezer running, we drop about 8% overnight or 36AH. Not sure if you have water cooled fridges on the 55, but the homemade Frankenstein brushless pump (detailed in another post) has reduced power consumption considerably. Freezer is colder, too! You also stated that you figure about 5kw a day, which should be 5000/25.6v = 195AH, which sounds more realistic. Or are you running other items that we're not? In any event, I don't think your 750w on gel will be enough to eliminate genset usage most days if you are anything like us. 2 fridges plus a freezer and computers on, electric kettle, microwave and plus, the admiral has gotten addicted to Ozark, so the TV is on quite a bit. :) That said, we also run the water maker off our batteries and the 2.2kw scuba compressor if the batteries get too full. But I still suspect 750w on gel won't be enough.

Dan - have you considered adding more AC-based charging capacity? If you have to run the genset, since you have lithium, which can accept high currents, might as well add as much charging capacity to reduce genset runtimes. Your calculated figures on $/hr for genset usage frightened me into looking at more solar! And it's not just the money, I am consciously trying to reduce ongoing maintenance. With our 200amps charging capacity, on the rare instances we run the genset, it's almost always for less than an hour. I suggest rewiring that water heater. We do, in fact, run the water heater on battery/inverter. Our heater is only 700w and I run it for say 20 minutes prior to each shower, which gives me just enough hot water for 2 people.

Eric - no need to add extra ventilation, at least on our passage berth mounted batteries. I have monitored individual battery temps via bluetooth and they rarely get above 30c. They only get hot (40c or so) when I'm running AC-based chargers at 200amps and try to take them to 90%+ in order to balance out the batteries and help the battery monitor reset.

Justin - do you have the hardtop panels on a separate MPPT? Once you get on your boat, I am really really curious to know how many AH you get out of them, compared to your aft panels. Another boat we met in FP has 2kw of solar on their decks and they produce about the same kWH per day as we do with only 960w of arch mounted solar. Much of that inefficiency is probably related to shading, but if you look at the specs on most panels, the power output drops about 0.3-0.5% PER degree C increase over 25degC. I measured the panel temps on mine and it's not much above ambient since they get cooled by the breeze blowing underneath them. I would love to add them but it would be a lot of brain damage for me, so I want to make sure it's worth the effort or maybe I just accept I'll have to run the genset every few weeks.  

Ken is very right with the weight balance issue! I am sick of scrubbing the port side gelcoat! 

At the end of the day, energy is like money - the more you have, the more you use!


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com

 


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Chantal & Alain sv Makemo
 

Hi Ken,

Thank you for sharing your positive experience with LifePo4 batteries.
Would you be kind to answer 2 questions about this marvelous change?
what did you change in your charger/ converter equipment Coming from AGM or Gel batteries ?

Regarding the cost of your 600Ah LifePo4, this is incredible to me (European) while I am trying to find the best price offered on the web w/o considering at this stage I would have to buy from the West Indies probably much expensive units. Where did you buy yours?

thanks so much for the great experience again
cheers
Alain
sv Makemo


Billy Newport
 
Edited

My last boat, I had 1200w of solar and each panel had its own mppt controller. I think I had 16 controllers, genasun typically with 2 victrons for the largest panels. Besides the insane wiring, I got 90A@12v out of that peak and it managed shade very well but that was expensive to do.

Here is a link to a phot album on Google of that boat.

https://photos.app.goo.gl/YZv6xncC821Rquqn8


Dan Carlson
 

Hi Scott,

Thanks for your ongoing engagement in the Amel topics on the forum. Providing both your experiences as well as questions for others. 

Regarding AC capacity: I have 90 amps which is all I have found that I need at this time. I have the 230v water-maker and so I need to run the generator 2 to 3 hours per week for the water maker. That leaves me with extra generator capacity to also run the water heater and either 30 or 60 amps of charging. That is more that enough charging for any shortfall in solar that I have here in the Caribbean. I can't remember the last time I ran the generator just for battery charging. 
Regarding the water heater; I've been working on the best way to wire in a switch to be able to supply the 230v panel from the inverter I just need the right piece of faceplate for mounting the switch to be able to complete the job. So far we've not had a strong need, as I do heat water a few times a week when we run the water maker, and also when we run the main engine for an hour when moving the boat around between anchorages that creates a tank of hot water that lasts us almost three days here in the Caribbean.

Thanks and regards, Daniel Carlson on sv BeBe, SM #387

On Thu, Feb 4, 2021, 1:23 AM Scott SV Tengah <Scott.nguyen@...> wrote:

Hi everyone,

In FP and Hawaii, we were averaging 5500-6000wh per day. Most I've seen is a handful of days approaching 7000wh. As Mark mentioned, we have a lifepo4 bank (2.5 years now) and that makes a huge difference as you can see when you compare my data to Porter's with similar solar output and similar environmental conditions. I'm sure you all see that once you take a lead battery above 80%, the charge acceptance drops like a rock. And worse, you're supposed to keep lead at high SOC to prevent sulfation so a lot of your solar output will be wasted. With my bank, the full output of the solar (or the 200amps of AC-powered charging) is taken up by the batteries until the upper 90% SOC. And I try to keep the batteries between say 50-80% to maximize longevity, so literally every watt is being put into the batteries.

Another thing that Mark didn't mention, but makes a huge difference is that lifepo4 charging is much more efficient than lead charging. With lead, you lose about 20-30% of your the charge current through inefficiencies. read: heat. With lifepo4 over 2.5 years I'm losing about 2-3%, based on the cumulative data on kWh in compared to kWh out that is provided by my Victron MPPT.

Billy - I suspect something is wrong with your battery monitor? We have 450ah and with 2 fridges and a freezer running, we drop about 8% overnight or 36AH. Not sure if you have water cooled fridges on the 55, but the homemade Frankenstein brushless pump (detailed in another post) has reduced power consumption considerably. Freezer is colder, too! You also stated that you figure about 5kw a day, which should be 5000/25.6v = 195AH, which sounds more realistic. Or are you running other items that we're not? In any event, I don't think your 750w on gel will be enough to eliminate genset usage most days if you are anything like us. 2 fridges plus a freezer and computers on, electric kettle, microwave and plus, the admiral has gotten addicted to Ozark, so the TV is on quite a bit. :) That said, we also run the water maker off our batteries and the 2.2kw scuba compressor if the batteries get too full. But I still suspect 750w on gel won't be enough.

Dan - have you considered adding more AC-based charging capacity? If you have to run the genset, since you have lithium, which can accept high currents, might as well add as much charging capacity to reduce genset runtimes. Your calculated figures on $/hr for genset usage frightened me into looking at more solar! And it's not just the money, I am consciously trying to reduce ongoing maintenance. With our 200amps charging capacity, on the rare instances we run the genset, it's almost always for less than an hour. I suggest rewiring that water heater. We do, in fact, run the water heater on battery/inverter. Our heater is only 700w and I run it for say 20 minutes prior to each shower, which gives me just enough hot water for 2 people.

Eric - no need to add extra ventilation, at least on our passage berth mounted batteries. I have monitored individual battery temps via bluetooth and they rarely get above 30c. They only get hot (40c or so) when I'm running AC-based chargers at 200amps and try to take them to 90%+ in order to balance out the batteries and help the battery monitor reset.

Justin - do you have the hardtop panels on a separate MPPT? Once you get on your boat, I am really really curious to know how many AH you get out of them, compared to your aft panels. Another boat we met in FP has 2kw of solar on their decks and they produce about the same kWH per day as we do with only 960w of arch mounted solar. Much of that inefficiency is probably related to shading, but if you look at the specs on most panels, the power output drops about 0.3-0.5% PER degree C increase over 25degC. I measured the panel temps on mine and it's not much above ambient since they get cooled by the breeze blowing underneath them. I would love to add them but it would be a lot of brain damage for me, so I want to make sure it's worth the effort or maybe I just accept I'll have to run the genset every few weeks.  

Ken is very right with the weight balance issue! I am sick of scrubbing the port side gelcoat! 

At the end of the day, energy is like money - the more you have, the more you use!


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Paul Osterberg
 

Alain!
We did not changed anything in our charging system, I had a 5 year old Victron Multiplus charger/inverter works great with Li, My very old Dolphine charger works great as well. My old alternator had before an external Balmar regulator, the only thing I did was to add a temp sensor for the alternator, must admit still on the hard so have not yet started the engine, but see no reason why it should not work. The BMS opens the field winding, when battery "fully" charged. For solar I have 4 Victron MPPT works great so far
Can now run all 220 v gadgets on my 540 Ah LiFePO4, including AC, and hot-water. The issue of course is how to recharge? We have 1,4 kw of solar and Swi-Tec hydrogenerator. Plan not to use the Onan. Yesterday it was raining most of the day and clouds close to 100% of the time still got in 60 Ah from the 1,1 Kw solar currently active. That is in the beginning of Feb when the sun is very low on the sky. Place Lagos Portugal. Solar is fantastic.
Paul on SY Kerpa SM#259


 

Paul,

I believe that you should research spike back voltage to the alternator protection from Lithium Batteries. Every Preferred Vendor of Lithium/LiFePO4 batteries recommends the same Sterling Power Alternator Protection Device 24v. This is less than 100 euro. Maybe they could be wrong, but I don't think so.
image.png
Bill
CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar


On Sat, Feb 6, 2021 at 3:47 AM Paul Osterberg <osterberg.paul.l@...> wrote:
Alain!
We did not changed anything in our charging system, I had a 5 year old Victron Multiplus charger/inverter works great with Li, My very old Dolphine charger works great as well. My old alternator had before an external Balmar regulator, the only thing I did was to add a temp sensor for the alternator, must admit still on the hard so have not yet started the engine, but see no reason why it should not work. The BMS opens the field winding, when battery "fully" charged. For solar I have 4 Victron MPPT works great so far
Can now run all 220 v gadgets on my 540 Ah LiFePO4, including AC, and hot-water. The issue of course is how to recharge? We have 1,4 kw of solar and Swi-Tec hydrogenerator. Plan not to use the Onan. Yesterday it was raining most of the day and clouds close to 100% of the time still got in 60 Ah from the 1,1 Kw solar currently active. That is in the beginning of Feb when the sun is very low on the sky. Place Lagos Portugal. Solar is fantastic.
Paul on SY Kerpa SM#259