I am currently stuck in Thailand, and as many of you know Zivile and I have a YouTube channel about our circumnavigation.  Sailing Aquarius.  Over a Year ago I did a video about batteries, and the video made the case for buying LiFePO4 batteries.
https://www.youtube.com/watch?v=BcWBiDnB794
I think this has a lot of good information about the LiFePO4 batteries, and the systems on a SM.

I bought the Victron AGM batteries (8x110AH 12V) 3 1/2 years ago, and they were starting to get tired.  When new I had 440AH at 24V, thus about 220AH of usable.  After 3.5 years of sailing, and using the bow thruster, and picking up the anchor all without the Genset running, my batteries were giving me about 110AH of usable power.  Every morning I was getting closer and closer to 24.6V, and hit it a few times.  

Being in Thailand, I could not expect BattleBorn to be competitive with no one in Thailand, so I started doing research.  

I am currently doing a video about the batteries I ended up with, and should release it next week.  But, I found that in Thailand I was able to get a custom made LiFePO4 battery 24V 300AH for about $1800.  I bought 2, and made them sized so that 3 will fit in the SM.  That means you could get 3 batteries for slightly more than I paid for Victron AGMs and you would have 900AH at 24V.  This was a game changer - I can run the AC with my 600AH battery pack for 3 hours a night without running the Genset.

I will release the video next week.  But this was a game changer!

Ken Powers
Aquarius SM2K 262

Hello Ken,

Great vidéo informative and entertaining.

I understood you went for 12V Lifepo. On the chat it was advised to go for 24V Lifepo that would better balance the cells by the integrated BMS.

But then you can’t use it for emergency start of the engine (or the generator) without a 24V to 12V transformer which has added cost and something more to not work when needed the most.

is this correct ?

Thank s

Denis 
Meltem 32

Great that you took the plunge. Those Agm batteries aren't cheap so if you can keep your lithium alive, I'm certain it will save you money over the long term. 

I'm a little confused on your air con runtime on battery. Not sure about the sm, but on our 54 we have a Climma 9 in the aft cabin, which draws 782watts/26.3v=29.7amps and the calpeda pump draws 14 amps. FYI the voltage is what my victron has calculated as the average voltage under draw during the last two years. The climma draw is per spec, but only when the compressor is running. So even assuming the extreme/unrealistic case of 100% duty cycle, that's 44 amps an hour or around 132 amp hours over 3 hours. With your 600amps at 24v, you should be able to run much longer than 3 hours. Perhaps your battery monitor is not calibrated correctly? Or perhaps you're talking about running all 3 air con units? 

I'm always excited by a cheaper way to do the same thing. The victron / master volt setup is far more expensive but I guess two years ago when I installed it, I was so inexperienced with this lithium stuff and given the catastrophic battery failure and boat damage that can occur if you don't have the proper safety measures in place, I was too chicken to try it on my own. 

Excited to see how you managed those risks for far less cost than we (Garulfo, Joerg, myself) did. Too late for me but perhaps it can help others. 



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

Hi Scott,

Actually, I only run the AC for 3 to 4 hours because I don't want to cycle the batteries too low, and I also want to save battery for the next day.  If the batteries are full,  I could run the AC all night long.  But, it is still a game changer just to get the cabin cooled down, so I can get to sleep.  40Amps x 10 hours, should not be a problem.

My batteries cost $1800 each, so I spent $3600 on the batteries (plus $500 shipping totaling $4100).  But, for 600AH at 24V, that is an amazing price.  It is almost as cheep as building the batteries yourself out of single cells, and buying a good BMS.  O, and this is cheaper than getting good AGM's.   I would consider using single cells next time where I get to choose the BMS.

I have done a lot of research on LiFePO4 batteries, and catastrophic failure of a LiFePO4 battery is probably rarer than that of lead acid.  You can short them, shoot them, or overcharge them and though they will be destroyed, they are not going to burn.  Today, the weak link in the LiFePO4 batteries is the BMS.  Almost all cells used by any reputable battery manufacturers are, 1) made in China, and 2) pretty dam good.  They should all last about 5000 cycles if used and maintained properly.  

Cheers,

Ken

This is my first posting to the forum. I am planning out my future with a buddy for circumnavigation and living on the boat. I am going to get either a SM2k or a Beneteau 57. Batteries are a huge plan for me. I have done tons of research on what to use and what my plans are. Most likely our usage will be as much as Delos (200+ amphr daily). During the Zoom meeting there were places for questions that were not answered. 

Denis - Yes Bill and Battle Born did recommend the 24v  over the 12v. BUT..... the BMS used in Battle born, whether the 12v or 24v batteries, will balance the cells just fine and going with the 24v ones won't make a difference. The Battle Born rep even said that but if you weren't paying attention closely you would miss it. The BB BMS are robust and the batteries are built better than all the rest being made these days. Worth the extra expense. However, IF BB would make a 24v with more than 100 amp hr capacity, in the same size Group 31, and price it lower than 2x the 12v price, I would be highly interested in that setup. Due to the 50amp hr current size it still would take 8x of them. I would rather do the 12v ones which allow for that emergency usage. 

As a thought - I also am considering if purchasing the SM2k doing a separate 12v bank purely for electronic usage and anything 12v. The Beneteau 57 has a 280amp hr bank for that and separated the 24v bank. Haven't done the calculations for that completely but would dedicate 1x solar panel for keeping that topped off (engine alternator when running also) and be able to charge cameras, flashlights, and run the depth and wind MFd's all day everyday without draining any of the main battery bank. Might be a bit over the top, but it would help. Options for extending the banks could be to put 2x extra 24v bank batteries in the aft clothes locker beside the bank or put them beside the nav station on the floor. Putting that extra pair should be fine as long as all the wires running to the unswitched distribution block from all the pairs are of equal length. That way they will all charge and discharge the same. 

Solar panels - I also noticed MOST people, lets say having 3x panels, have one MPPT to charge the bank. That one MPPT is the same cost as what 3x MPPT's would be for each panel due to inputed power levels. So if you had 3x MPPTs you would have complete redundancy if one went bad. Same cost. 


Starter -  yes if you use 24v ones you would have to have a step down to 12v for that power. 

Phillippe - Please watch on YouTube    DIY with Will Prowse  and he shows PLENTY of low prices LiFEPo4 12v Group 31 batteries that are taken apart and investigated. He always finds issues with them such as not producing the stated amp hrs they should, cheaply made BMS circuits, incorrect sized wires inside the batteries, and poor sodering of terminals inside. Some could melt due to high flows of amps pulled during usage due to incorrect wires and some mislabeled relays. Make your decision off your research and what you can learn from those informational videos. 

I watch Ken's videos and enjoy them. I will be for sure watching his new setup and seeing how it works out. Same for Delos - most don't know and I don't think Brian mentioned it during the Zoom video but they had a 8x 12v 100amp hr setup.  Not sure why but about 2 yrs into it (July 2020) they changed those out for new BB batteries and I wonder why. If aiming for higher amp hrs I get it. But I am highly interested in when his video in a month or so comes out to find out why they changed them. 

I have done some minor estimations ---   if you use 200 amp hrs daily, and also have 900w of solar, you will cycle (each cycle is one full discharge of a battery bank capacity) once per 3 days or so. That is a bit over 115 cycles per year living on the boat. If the LiFPo4 batteries get 4k+ cycles (85% capacity at that time) that would be 40 yrs of usage. If that is the case then spending 2-300 more per battery to get the BB ones, which are the best, seems highly worth spending that extra money rather than trying to find a steal. This is the lifeblood of the vessel and something you will use every day so why risk it. This is of course IMHO. 

PS - If we all could run the AC unit or units off the bank I am sure we would. However take a look at the Gone with the Wynns website and on there they have a video explain a "soft start" modual that attaches to the ac unit and will drastically lower the amp hrs used and keep the kick start amp hrs way down. It manipulates the start up sequence to prevent the spike. This possibly if utilized would allow more usage of the AC's in a hot climate. I will be installing at least 1 if not for all three units. 

Hope this helps as I am learning myself

He Ken
So i think shout prevere 24 V batteries with a BMS on each batterie ?? Is it right ?

Thanks
Elja
SM Balu 222

Von meinem iPhone gesendet

Elja,

Each LifePo4 battery has some type of BMS. Most are internal. IT manages the charge and draw down for each of the cells inside it. Prevents overcharging, prevents draining the battery, and makes sure the cells are evenly charging and discharging among other things. ALL BMS's are not equal. There are quality issues with many on the market. 

Ken
i ask Victron for his batteries a BMS for all batteries
There is my concern if this fails and it is not noticed all batteries damaged if each battery has a BMS is only one damaged.

Elja

Von meinem iPhone gesendet

Elja,   I am pretty sure ALL lifePo4 batteries have a built in BMS inside the casing. So each battery has one. You would NOT want one for a whole bank from what I understand. If that were to malfunction then you could lose the whole system rather than just one battery. The BMS is what regulates the charging and making sure all cells charge up evenly. 

I ordered 16x270 Ah prismatic cells from China for a DIY system, guess i get them 5-6 weeks from now, That will give me 540 Ah 24 volt, probably go for a rec BMS (compatible with Victron system), will make video and post on the forum when ready. Will take ample time for installations as it is a few cables that I will replace and tidy up when I'm at it. For the one who use drop in, make sure they not only rated to run your bowthruster but also capable in real life, in some drop in the internat cables and BMS are not for high loads. can recommend Will Prowse on youtube very illustrative and easy to follow, he have teared a few drop in batteris apart and had a look what was inside, some of them you do not want to have onboard.
Paul on SY Kerpa SM#259, lags, Portugal sykerpa.com

Hi Sheriffdep,

It depends what you call a LiFePO battery. But I can tell you without a doubt that the (prismatic) cells you can buy at AliExpress and other sites have no BMS build in.
Having a BMS overseeing the full battery bank is useful for cell balancing. Mastervolt is/was using Chinese Wilson cells in their batteries with a proprietary BMS on top of it enabling it to communicate with other Mastervolt stuff across the Masterbus interface. Very nice but very expensive.

This is my biggest problem with Battle Born batteries. You cannot have sensible interfacing with other systems.
Lithium batteries like to be kept between 20 and 75% state of charge if you have extended charging facilities (i.e. shore power) . The voltage alone makes it very hard to determine the state of charge when a system is at use. Basically you need a Coulomb counter to see the SOC at any point in time. Ideally your BMS should provide you with this information and adjust the float voltage of any charging device in such way it can maintain a desired SOC after bulk charging. Given the different sources of charge you can have on a boat this is not so simple.

Personally  I'm still looking for a BMS that can handle this task without me having to reconfigure everything every time I go out sailing. But I'm on shore power most of the time.

Kind Regards,

Arno Luijten
SV Luna,
A54-121

Arno,

Can you explain further the BMS BB communication issues? 

Am I wrong in saying Most drop in sets have the BMS? I know you can make the cells yourself and then add outside BMS but thought the self contained ones all came with them. 

My thoughts  -  Making a custom system and filling the battery box on the SM2k and having a ton of amp hrs avaialable seems easily doable. However, not done the math, but I think financially it wouldn't be that drastic of a savings to where I would want to lets say risk the investment. Everyone has their own risk tolerance. Like a lot of the china made current batts they range from $550-800 where the BB are $850-950. Seems the BB are the most robust and best made so since this is a 15-30yr investment that little amount is peanuts overall.  

Either custom setup or OEM drop ins with the available space I do want to maximize the amp hrs usable. I will be a heavy user for sure and don't want to run the gen. Any ideas or places to research?? 

Thanks, I hope this helps others along with me

Some of my thoughts, original in regular font and my response in italics

Sheriffdep

As a thought - I also am considering if purchasing the SM2k doing a separate 12v bank purely for electronic usage and anything 12v. The Beneteau 57 has a 280amp hr bank for that and separated the 24v bank. Haven't done the calculations for that completely but would dedicate 1x solar panel for keeping that topped off (engine alternator when running also) and be able to charge cameras, flashlights, and run the depth and wind MFd's all day everyday without draining any of the main battery bank. Might be a bit over the top, but it would help. Options for extending the banks could be to put 2x extra 24v bank batteries in the aft clothes locker beside the bank or put them beside the nav station on the floor. Putting that extra pair should be fine as long as all the wires running to the unswitched distribution block from all the pairs are of equal length. That way they will all charge and discharge the same.  
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com

He Scott , first many thanks for your detaild awnser . 

Hi Sheriffdep,

Drop in replacement have build in BMS-es that is correct. The quality of those can be from excellent to abysmal and you have very little clues to determine this from the outside.
I do think that assembling your own battery pack is currently the best way forward if you have technical skills. It's cheaper and you determine for yourself which BMS system gives you the best facilities for your usage case.
It also enables you to make better use of available space. An example of company that facilitates this route is https://shop.gwl.eu/index.php?force_sid=nc4jtsqa8h85c6d1m7j3t8ncnj& (I have no relation with them and never bought anything there)

Your assumption about 15-30 year investment is highly optimistic at best. Personally I would assume a lifespan of 8 years simply as a result of lack of evidence that these things last longer. Your best bet is looking at the way Tesla's from 2013 are behaving and those use different chemistries (Li-Ion instead of LiFePO)
As said before, my main beef with this stuff is that to get the best life expectancy from these things you need to treat them carefully, meaning not fully empty or fully charged for extended periods and keeping them balanced. Most systems can only balance them at 100% SOC. This means you will need to think of the SOC of your batteries in relation to your cruising plans and modify the configuration accordingly. The latter is can be quite the hassle as you need to "tell" all your charging sources to keep a certain maximum float-voltage (more accurately maximum SOC). Alternatively you can also make them stop charging, but that means you will be short-cycling the batteries needlessly because of the never ending consumption by systems on the boat. The effects of this are unknown to me and I cannot find clear information about it. It also means your battery bank is not "set and forget" as many supplies claim is some form or shape.

My point is that it is not so hard to put a well working system together but designing one that minimizes stress on the battery system and maximizes longevity is quite the challenge. It is also depending on your use-case provided you can predict that for the coming 8-15 years (I can't). The Battle Born batteries give you very little to control the SOC and don't provide you with information on what's going on inside the black box. Their 10-year warranty doesn't mean much to me. Who knows if the company is still around in 10 years and what they will tell you then.

So in the end, I think there are some good reasons to switch to Lithium but life-span discussions in relation to total cost of ownership and comparing them to alternatives are risky at best. My thought is that the charge/discharge curve of lithium and the lack of need to charge them to 100% every time are the VERY big plus arguments. All other points are secondary and maybe even debatable.


Cheers,

Arno Luijten
SV Luna,
A54-121

I was searching over internet for marine Lithium Batteries and found the “Ionic” brand that sells a 12V 125 Ah with the same size of the BattleBorn 12 100 Ah battery.
Ionic only give 5 years warranty vs BB 10 years, but they will provide 25% more capacity for our boats and each battery can be monitored independently with a smart phone via blue tooth communication.
I am inclined to go BB but wonder if any one has heard good or bad things of the “ionic”

Jose Venegas
IPANEMA SM2K 278
Curaçao

Sounds about right with Mastervolt. I haven't studied their system in detail but from what I've seen, they're the most hands off, from the user perspective, that I've seen. But you pay for it!

I have the Mastervolt alternator and Alpha pro II (3 is even better) and it took me over a year and the help of an engineer who used to break into car ECUs to reprogram them. It turned out to be quite simple, but neither Victron nor dealers understood the problem or could provide the solution.

I describe how I do it here:
https://amelyachtowners.groups.io/g/main/message/50689

One final alternator tip: I did not use the standard lithium profile on the mastervolt charge controller. This is because I did not want to keep the lithium batteries fully charged when motoring for a long time as this is not good for the batteries. I set the absorption voltage for 27.5v and the "float" at 26.5v. As mentioned before, voltage is NOT a good indicator of SOC, but I've seen over the last two years that this seems to result in charging stopping at around 85% on my system.  You'll need a Mastervolt USB interface to program your charge controller.

https://www.mastervolt.com/products/masterbus-interfaces/masterbus-usb-interface/


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

Arno,

I actually think if you're on shore power most of the time, lithium is a bad idea. At best, it's a waste of money that adds additional complication. 

I do agree with your lack of confidence in the warranty. Unless you are using batteries and chargers from one brand, I am almost certain the battery manufacturer will point fingers at the charger and you will left paying for a new battery bank yourself. 

For me, the big pluses are the charge/discharge curve as you mentioned, the lack of need to keep it full, the ability to run virtually all 220v appliances on battery and one thing that people don't often think about is that it could effectively double your solar output. The charge acceptance rate and near nonexistent charging efficiency issues means that, for the same solar array, you will get almost twice as many AH per day into your batteries compared to lead. I believe it is Porter who is in the tropics and has a similar solar array and the same MPPT as we do, but we are able to put nearly twice as much cumulative power into the batteries as he is. Our only difference is AGM vs. lithium.

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

He jose