LiFePO4 Battery Build

If you have 12 of the 304 (might as well as about same price and size as the 280 Ah), you’ll have about 912 Ah nominal with 80% usable of 730 Ah.

The other thing you’ll have to consider is how to charge such a large battery bank. It could take 6-12 hours (assuming you have a 100A or so chager on your inverter) if fully depleted. A lot longer if all you have is something like the standard Pronautic that came with most Sea Rays.

Tom might have some input on charging these puppies up, but it is quite a change to go to high output alternators which would be my first choice.
Yep, I'm considering my charging choices now. I'm leaning towards having 3 inputs - Solar (already in place), Alternator (will likely need to upgrade to HO alternators) and House charger. I may add a dedicated charger just for this bank, and tap into the converter line going to the other charger. that way I can program this one for Lithium and leave the other for Flooded Lead. I will work on designing that part now that I have a source for the batteries and have that part of the equation done. Thanks again for the leads on the cells!
 
If you have 12 of the 304 (might as well as about same price and size as the 280 Ah), you’ll have about 912 Ah nominal with 80% usable of 730 Ah.

The other thing you’ll have to consider is how to charge such a large battery bank. It could take 6-12 hours (assuming you have a 100A or so chager on your inverter) if fully depleted. A lot longer if all you have is something like the standard Pronautic that came with most Sea Rays.

Tom might have some input on charging these puppies up, but it is quite a change to go to high output alternators which would be my first choice.
I'm unsure what they are intended for. Inverter only? 12V or 24V? If for inverter only then definitely set up to the higher voltage as all of the conductor sizes cut in half. So the limitation for charging is not only what the batteries can consume but more importantly the BMS you plan to utilize. Many BMS will only support 0.25C which is pathetic. This is an area where you get what you pay for. Strive for a BMS that will match the battery assembly that it is monitoring; you really need as a minimum a 1C charge/discharge capable BMS. For these battery systems I'd stay from the standard chargers like the Pronautic line - you will smoke them and they really don't have the tuning finesse to take care of those batteries. I'd seriously look to invest into a 5KVA Victron Charger/Inverter with their GX control system with large shunt. These can support up to 120A charge current which will get you charged (730 AH) in around 6 yours. I'd have to sit down and calculate out all of the options to net the best profile however.

Edit - if you are desiring multiple interfaces and switching then look at the Victron Quattro series.
 
With 12 cells, I has assuming 3 x 12v battery assemblies each assembly being 4 cells. I have a Magnum 2812 with a 120A charger, and I’m looking at about 4 hour recharge. Adding the 3rd battery would be about 6 hours.

As for the BMS, it really acts as a programmable fuse and fail safe, but should not be ignored. The JBD 200A works just fine.

The trick to getting these batteries to work and last is to do a thorough top balance on the cells, and the set your inverter/charger to cutout somewhere in the 90%-10% SoC range and use quality battery monitor.

Victron is top notch stuff, but I’m also pretty happy with my Magnum Energy 2812. I’d prefer 24v, but I’m already committed.

Victron has great connectivity and if starting from scratch…I’d go this way. I even bought a Victron Multi for testing, and set up their Venus firmware on a raspberry pi for system monitoring. Unfortunately, cost to convert was too high and I’m back to the original.
 
Dave,

All I'm going to say is that you have now joined @ttmott as "a steely eyed missile man" in my mind.

That is a true "Badge of Honor" on CSR...

Heck - I'm just waiting for Starlink to replace my KVH!!!!
That a pretty big "badge if honor" to even be mentioned in the same post as Tom! Thanks.
 
With 12 cells, I has assuming 3 x 12v battery assemblies each assembly being 4 cells. I have a Magnum 2812 with a 120A charger, and I’m looking at about 4 hour recharge. Adding the 3rd battery would be about 6 hours.

As for the BMS, it really acts as a programmable fuse and fail safe, but should not be ignored. The JBD 200A works just fine.

The trick to getting these batteries to work and last is to do a thorough top balance on the cells, and the set your inverter/charger to cutout somewhere in the 90%-10% SoC range and use quality battery monitor.

Victron is top notch stuff, but I’m also pretty happy with my Magnum Energy 2812. I’d prefer 24v, but I’m already committed.

Victron has great connectivity and if starting from scratch…I’d go this way. I even bought a Victron Multi for testing, and set up their Venus firmware on a raspberry pi for system monitoring. Unfortunately, cost to convert was too high and I’m back to the original.

I'm going to replace my solar charge controller with Victron, and anything else that I can replace with Victron I will as well. My Inverter is a 3 year old Xantrex that has been working fine, so I'll need to think about that one. If I have the physical room to replace it with a Victron Charger/Inverter, I will, I'm just not sure it'll fit and I'm not sure where I would put it if it doesn't.
 
Hey Dave, how goes the build? I just got word from my battery supplier that they will be getting my shipment in on Jan 15, so I'm going to start planning the box build and ordering parts (BMS, charge controller, charger/inverter, etc).
 
Great information here just at the right time. I'm doing a winter build of a solar generator for my boat (1989 440 AC). My diesel generator died last year. I removed it, and have decided to replace it with a LiFePO4 battery bank, inverter, and solar panels. I bought an "all-in-one" AC charger/inverter/solar control by Growatt (24V, 3000W), and have 16 280 Ah cells, and three 400 W solar panels. I'm creating stand-alone 12V batteries, each with a BMS, combining pairs in series to create two 24V batteries, total of about 1.3 KW. I'm hoping that should be enough capacity to run microwave, stove, refrigerator, and even AC/Heat for short periods of time. I plan to charge from solar, shore power, and alternator.

Lots of good concerns and solutions already mentioned in this thread. Thanks so much.
 
Great information here just at the right time. I'm doing a winter build of a solar generator for my boat (1989 440 AC). My diesel generator died last year. I removed it, and have decided to replace it with a LiFePO4 battery bank, inverter, and solar panels. I bought an "all-in-one" AC charger/inverter/solar control by Growatt (24V, 3000W), and have 16 280 Ah cells, and three 400 W solar panels. I'm creating stand-alone 12V batteries, each with a BMS, combining pairs in series to create two 24V batteries, total of about 1.3 KW. I'm hoping that should be enough capacity to run microwave, stove, refrigerator, and even AC/Heat for short periods of time. I plan to charge from solar, shore power, and alternator.

Lots of good concerns and solutions already mentioned in this thread. Thanks so much.
I think your math is off somewhere, but it could be a typo. 1.3kW is not that much power, especially for things like stove and ac/heat. A good Group 31 battery has a total capacity of about 1.4kW (although for frequent discharges, only about 50% of that is available). Perhaps that was supposed to be 13kW?
 
Great information here just at the right time. I'm doing a winter build of a solar generator for my boat (1989 440 AC). My diesel generator died last year. I removed it, and have decided to replace it with a LiFePO4 battery bank, inverter, and solar panels. I bought an "all-in-one" AC charger/inverter/solar control by Growatt (24V, 3000W), and have 16 280 Ah cells, and three 400 W solar panels. I'm creating stand-alone 12V batteries, each with a BMS, combining pairs in series to create two 24V batteries, total of about 1.3 KW. I'm hoping that should be enough capacity to run microwave, stove, refrigerator, and even AC/Heat for short periods of time. I plan to charge from solar, shore power, and alternator.

Lots of good concerns and solutions already mentioned in this thread. Thanks so much.
It won't by a long shot. Your combined loads are well in excess of the 3KW inverter. Hypothetically let's say you are going to draw 2.5KW not considering the inductive (power factor) and starting loads. 1.3KW total battery capacity will net that gives you a grand total of 25 minutes run time to a depth of discharge of 80%.
 
And I won’t run the heavy loads simultaneously. I’m ok with balancing the load by turning loads on and off.
 
Hey Dave, how goes the build? I just got word from my battery supplier that they will be getting my shipment in on Jan 15, so I'm going to start planning the box build and ordering parts (BMS, charge controller, charger/inverter, etc).

I've been working and other boat projects took priority (had the boat hauled and the props/bottom work done in early December). I'll be getting back to this in the next couple weeks.

I have all the materials waiting to go.

The only last decision is the battery box choice. The ABS ones I purchased are a little tight with the batteries and the BMS, so I need to think that aspect through.
 
And I won’t run the heavy loads simultaneously. I’m ok with balancing the load by turning loads on and off.

I thought about the same project. Document what you do. I'd be very interested to see how it turns out and works in practice.
 
I've been working and other boat projects took priority (had the boat hauled and the props/bottom work done in early December). I'll be getting back to this in the next couple weeks.

I have all the materials waiting to go.

The only last decision is the battery box choice. The ABS ones I purchased are a little tight with the batteries and the BMS, so I need to think that aspect through.
Happy new year Dave! For those prismatics I'd have aluminum boxes made; easy simple welding job using 12 gauge or 1/8" plate and obviously lined with an insulating material like previously discussed. There are some reg's coming down that you need to get in front of so when your insurance requires a survey you are good to go. If I was to advise I would mount the BMS on the outside of the aluminum battery box so heat dissipation isn't an issue. The one big thing coming probably this year is a monitor capability remote from the batteries.
F1915-Module-4-0-DIN-45.png
 
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Happy new year Dave! For those prismatics I'd have aluminum boxes made; easy simple welding job using 12 gauge or 1/8" plate and obviously lined with an insulating material like previously discussed. There are some reg's coming down that you need to get in front of so when your insurance requires a survey you are good to go. If I was to advise I would mount the BMS on the outside of the aluminum battery box so heat dissipation isn't an issue. The one big thing coming probably this year is a monitor capability remote from the batteries.
F1915-Module-4-0-DIN-45.png
What is the remote monitor capability requirement??? Is a simple SoC gage enough? These batteries are isolated to the inverter charger, and that has remote monitoring of a lot of parameters...

As far as the containment box, what re the specs? I've been avoiding metal, due to this being a marine environment.
 
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What is the remote monitor capability requirement??? Is a simple SoC gage enough? These batteries are isolated to the inverter charger, and that has remote monitoring of a lot of parameters...
I understand ABYC is setting a threshold below/above the BMS trip, top and bottom charge; the monitor system will probably issue a warning upon entering the threshold then an alert before crossing the threshold into BMS shut down. I do know that the Victron and Ocean Planet batteries already do this via their propriety BMS monitor system. I also understand that Battle Born batteries will be coming out with a battery that interfaces with NMEA 2000 for those messages. I'm sure temperature is also one of those monitored parameters.
 
Getting towards the end of the top balance. With only 10A @ 3.XX volts (about 35watts) it was going to take FOREVER as this is over 8000Wh (3.2V *304Ah/cell*8Cells)!!

I did 2 things to speed this process up. I reassembled the into 4s assembly with the BMS attached an RC battery charger capable of almost 400 watts to bulk charge. I then reassembled into parallel set up and ran both chargers at 3.65V with a total of about 100watts of output. Still took 2 days+.

RC Charger says its done, smaller power supply still pumping just a little bit more. I'll wait for the current to drop to 0 at 3.65V and let them sit over night and recheck the individual cells.

View attachment 114740

David, I top balanced my 280 Ah cells 4 at a time (4.6V at 10A). Each set of 4 cells took 4 days! I was starting to believe I was doing it wrong, but no, it really does take a long time (mine started at 3.29V/cell). Once they reach about 3.4V, the charging goes quickly.
 
Good point about monitoring alarms for the lithium banks! I’ll have Bluetooth communication from both a Victron shunt and the BMS units, as well as WiFi communication with the Growatt inverter/charger/controller. They will all give me visual alerts, and likely audible alerts. Do you know what type of alarm the ABYC will require?
 
I had heard on a podcast that ABYC hosts (Youtube also) that the alarm requirement is based upon the use of the batteries. I would assume also that the "battery system" will eventually need to be ABYC certified, who knows. If the batteries are for navigation, engine start, boat safety systems or other critical functions then I would assume the alarm must be at the helm and in such a fashion that the captain and crew understand and can respond. What would be that response? I have no earthly idea as things can get complicated fast when these systems go south; is it a BMS failing, alternator issues, charger/converter problem, Inverter problem? Do you have to execute a third order polynomial to get it under control or safe the boat and watch it unfold.
If the batteries are dedicated to running a microwave I would expect the BMS would be adequate. But ABYC wasn't specific in my understanding. I think that my big concern is how the insurance companies will adopt and translate the new requirements. Some of the new yachts being built (eg Nordhaven) now pretty much power everything from lithium battery banks except for engine cranking and generator cranking. I'm sure they are using robust monitor systems that can terminate a bank and alternatively use a secondary....
On my system the designers have pushed back using lithium to crank the engines even though they easily could. So I'm going through another iteration in design.
 
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