Building 180Ah 12V LiFePO4 power pack

ShamusTX

Observer
CALB are top notch.

Link to Ali vendor you used?

A capacity test - discharge a load at CC rate, precisely timed - will show their State of Health relative to rated Ah.

Some vendors sell used as new, or factory seconds.

Some have been successful in buying direct, but probably pallet-quantities at least, if not a full conex.
My supplier

180Ah -> https://www.alibaba.com/product-detail/Prismatic-rechargeable-Lithium-LiFePO4-Battery-Cell_62006376520.html?spm=a2756.order-detail-ta-bn-b.0.0.2afd2fc2W92Yrm

100Ah -> https://www.alibaba.com/product-detail/High-capacity-rechargeable-Lifepo4-lithium-battery_60830395664.html?spm=a2700.icbuShop.89.14.62f93f51BjvHBJ

Plan to do a capacity test at some point, not at the 1C rating thou. Don;t have the ability to pull that amount of current. Just have not had time.
 

luthj

Engineer In Residence
FYI, the graphs and charts on that sellers website are generic, and used for multiple LFP battery types they sell. For CALB you can look up datasheets easy enough. They also appear to sell Frey batteries (blue case). For about 20% less.

Pricing is good though, and they support small orders. 16x100AH Frey cells is about $1.2k delivered (matches what I have seen others pay). But Import duty may add to that... At some point I will be ordering a bunch of cells to build a custom pack.

I think the best bet for higher current applications is to use a dual coil gigavac relay. High current, and low standby power ague.
 

ShamusTX

Observer
Its important to put some compression strapping on the batteries. It keeps them from moving, and provides support for the large plates inside.

Your bus bars will add cyclic stress to the battery internals, especially with batteries that can float in their box (even a mm or two is a big deal).

Did your batteries come with a test sheet? Ideally you want batteries with internal resistance within 2%, and capacity within 3%.

180AH cells are the Max side would use for a mobile pack, for something that will get tossed around like a portable pack, 100AH would be my preference. the bigger the cells, the more vulnerable to vibration damage.

Why did you feel the need to put two balances on the pack? At 45A max draw, you will not need more than 100ma based on my math. Having two of them increases the standby power consumption.
The batteries have no play width wise, very tight in each compartment. The batteries are also secured with aluminum straps, wrapped in shrink tubing, to make sure that they are not able to lift. The whole wood housing is flush with the top of the ammo can that will prevent vertical movement and I added braces to prevent lateral movement.

My original intent was to not have a BMS at all. Rely on the solar controller only and the active balancer. But if I ran an inverter then I wanted a way to cut the inverter off if the battery level go to low,. My solar controller is only rated at 30A and I really did not want to upgrade to a 60A model to be able to run a 500W inverter. So the easiest solution was to add a BMS and use it to protect the system for over discharge when using the inverter.
I also have to correct the information about the BMS, it only balances at 35mA.

The BMS was a standby current draw of 50uA@12V
The active balancer is <200mW in 4s configuration.
 

john61ct

Adventurer
Thanks a lot.
Plan to do a capacity test at some point, not at the 1C rating thou. Don;t have the ability to pull that amount of current. Just have not had time.
1C is **crazy** high just for capacity testing with big Kahuna cells.

Another nice thing about LFP, Peukert coefficient is so close to 1, the result will not change that much at different discharge rates.

Standard with lead is 20-hour rate or 0.05C

Anything between 0.1C and 0.5C should be fine.

Using a coulometer is a lot less precise, but just getting a ballpark is good enough for early days to flag if something major is wrong.
 

john61ct

Adventurer
Swelling does not affect the height or width.

It is the thickness dimension that "really should" (IMO must) be contained.

By strong metal endplates, like 1/4" aluminium securely strapped against very strong forces, lije a car jack.

Wood will not do the job.

I suppose keeping a close eye on them with calipers will do, go back and retrofit soon as you see more than a couple mm of swelling.
 

hour

Observer
Cool build. Just ordered some new 195ah 3.2v LFP cells that seem to have good reviews from aliexpress because I still don't know how to alibaba. Seller responds in perfect english to every reviewer, capacity has checked out across multiple of their ah offerings from reviewers using the same stuff as me (victron bmv, smartsolar). Seller also makes a point to send out perfectly matched cells and puts a label on each with the internal resistance and capacity.

Reusing the balancer/equalizer board (same one you have) from my existing setup and a deligreen BMS (80a) as well. I was a-okay with going the battleborn route but as long as these cells are decent I'll be happy to have easy access to the BMS should it ever need replacing. I also won a scratch ticket the other day that paid for the entire thing, so I could more easily justify living dangerously (non-CALB, generic looking blue wrapped cells).

Hope mine fit in a 30mm ammo can too with some shimming. The headroom between the top of the cells and the lid of the ammo can + that void in the front would come in handy for doing exactly as you did - mounting the BMS and equalizer inside, along with a small fuse block and my Victron BatteryProtect. Victron BMV shunt could probably go in there as well, with the face mounted too. Praise hole saw kit.

I didn't see if you mentioned which AC charger you got for $182? I'm considering just getting a big ass dual output hobby balance charger. A 600-1000+w one that accepts 9-49v, then a large 120v AC->48V DC power supply. Probably throw both in a toolbox with some strategic mounting and ventilation hole-sawing. Put a C14 plug inlet (like back of a computer PSU) and wire that to the power supply. Would allow monitored and balanced charging at custom voltage and current, the second of which will come in handy powering it from my generator at high elevation where it has significantly less umph.

Anyway, sweet. My average discharge is 29ah peak summer and 22ah thus far in September with things cooling off - running my 62qt dual zone fridge. Means if these cells aren't junk I should enjoy them for many many years to come if I can call them full at a storage voltage of 3.4v or less, and barely make a dent in them overnight. Thanks for thread.
 

john61ct

Adventurer
Seller responds in perfect english to every reviewer, capacity has checked out across multiple of their ah offerings from reviewers using the same stuff as me (victron bmv, smartsolar). Seller also makes a point to send out perfectly matched cells and puts a label on each with the internal resistance and capacity.
Such a tease! link please
 
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ShamusTX

Observer
Cool build. Just ordered some new 195ah 3.2v LFP cells that seem to have good reviews from aliexpress because I still don't know how to alibaba. Seller responds in perfect english to every reviewer, capacity has checked out across multiple of their ah offerings from reviewers using the same stuff as me (victron bmv, smartsolar). Seller also makes a point to send out perfectly matched cells and puts a label on each with the internal resistance and capacity.

Reusing the balancer/equalizer board (same one you have) from my existing setup and a deligreen BMS (80a) as well. I was a-okay with going the battleborn route but as long as these cells are decent I'll be happy to have easy access to the BMS should it ever need replacing. I also won a scratch ticket the other day that paid for the entire thing, so I could more easily justify living dangerously (non-CALB, generic looking blue wrapped cells).

Hope mine fit in a 30mm ammo can too with some shimming. The headroom between the top of the cells and the lid of the ammo can + that void in the front would come in handy for doing exactly as you did - mounting the BMS and equalizer inside, along with a small fuse block and my Victron BatteryProtect. Victron BMV shunt could probably go in there as well, with the face mounted too. Praise hole saw kit.

I didn't see if you mentioned which AC charger you got for $182? I'm considering just getting a big ass dual output hobby balance charger. A 600-1000+w one that accepts 9-49v, then a large 120v AC->48V DC power supply. Probably throw both in a toolbox with some strategic mounting and ventilation hole-sawing. Put a C14 plug inlet (like back of a computer PSU) and wire that to the power supply. Would allow monitored and balanced charging at custom voltage and current, the second of which will come in handy powering it from my generator at high elevation where it has significantly less umph.

Anyway, sweet. My average discharge is 29ah peak summer and 22ah thus far in September with things cooling off - running my 62qt dual zone fridge. Means if these cells aren't junk I should enjoy them for many many years to come if I can call them full at a storage voltage of 3.4v or less, and barely make a dent in them overnight. Thanks for thread.

195Ah batteries should fit, I also looked at the CALB 200Ah SE batteries and they were the same dimensions as the CALB 180Ah CA. The difference between SE and CA series batteries is the SE has higher energy density, and the CA has internal heat separators.

I also picked up a BMS8t and some GIGAVAV dual coil contactors, based on suggestions in this thread. The BMS I had worked fine but the BMS8t provides a lot more information about each cell and remaining capacity. Going to also redo the wiring to accommodate the new BMS and the gigavac GX21SB contactors. Also add strengthening plates to resist expansion.

This is the charger I got. https://www.electriccarpartscompany.com/Lithium-Battery-Charger-12V-20A-LiFePO4-LFP-Intelligent

I Used it to charge the cells and doubled checked voltages while charging with a voltmeter and Hyperion hobby charger w/ balancer connected. The AC charger charged to 100%, 140Ah added. I tried to use the Hyperion to discharge the battery, but it stopped after only 40Ah indicating voltage cut-off acheived. Which was wrong as the battery was still measuring 13.32 volts by the hobby charger and voltmeter.

I will try again with the capacity test once I get the new BMS installed and just use an inverter and 250W or 100W light bulb.
 

hour

Observer
195Ah batteries should fit, I also looked at the CALB 200Ah SE batteries and they were the same dimensions as the CALB 180Ah CA. The difference between SE and CA series batteries is the SE has higher energy density, and the CA has internal heat separators.

I also picked up a BMS8t and some GIGAVAV dual coil contactors, based on suggestions in this thread. The BMS I had worked fine but the BMS8t provides a lot more information about each cell and remaining capacity. Going to also redo the wiring to accommodate the new BMS and the gigavac GX21SB contactors. Also add strengthening plates to resist expansion.

This is the charger I got. https://www.electriccarpartscompany.com/Lithium-Battery-Charger-12V-20A-LiFePO4-LFP-Intelligent

I Used it to charge the cells and doubled checked voltages while charging with a voltmeter and Hyperion hobby charger w/ balancer connected. The AC charger charged to 100%, 140Ah added. I tried to use the Hyperion to discharge the battery, but it stopped after only 40Ah indicating voltage cut-off acheived. Which was wrong as the battery was still measuring 13.32 volts by the hobby charger and voltmeter.

I will try again with the capacity test once I get the new BMS installed and just use an inverter and 250W or 100W light bulb.
Yeah I've been tempted by the BMS8t via jonyjoe but I couldn't find much information about it across the entire web. Would be great if you could post the parts you ordered to accompany it (relays and whatever) and show some pics when you get it all set up.

Such a tease! link please

I'll be the guinea pig and post a thread on the "195ah" ones when they get here. If the terminals don't yank out, they're above 150ah, and they balance.. I'll be happy. But I think it'd be foolish to buy these blue mystery cells over the CALBs in this thread. I looked at the link Shamus posted for his cells days ago and somehow thought they were nearly $200 more than the ones I ended up with.
 

john61ct

Adventurer
link just brings the store page, hundreds of products listed.

Please post one to the specific page for the BMS?
 

hour

Observer
link just brings the store page, hundreds of products listed.

Please post one to the specific page for the BMS?
Yeah, I thought you were asking about the company's batteries, so I linked their store - and the first 50 items are their LFP offerings.

Didn't think you'd be asking about the Deligreen BMS...
 

deeznutz206

New member
Cool build. Just ordered some new 195ah 3.2v LFP cells that seem to have good reviews from aliexpress because I still don't know how to alibaba. Seller responds in perfect english to every reviewer, capacity has checked out across multiple of their ah offerings from reviewers using the same stuff as me (victron bmv, smartsolar). Seller also makes a point to send out perfectly matched cells and puts a label on each with the internal resistance and capacity.

Reusing the balancer/equalizer board (same one you have) from my existing setup and a deligreen BMS (80a) as well. I was a-okay with going the battleborn route but as long as these cells are decent I'll be happy to have easy access to the BMS should it ever need replacing. I also won a scratch ticket the other day that paid for the entire thing, so I could more easily justify living dangerously (non-CALB, generic looking blue wrapped cells).

Hope mine fit in a 30mm ammo can too with some shimming. The headroom between the top of the cells and the lid of the ammo can + that void in the front would come in handy for doing exactly as you did - mounting the BMS and equalizer inside, along with a small fuse block and my Victron BatteryProtect. Victron BMV shunt could probably go in there as well, with the face mounted too. Praise hole saw kit.

I didn't see if you mentioned which AC charger you got for $182? I'm considering just getting a big ass dual output hobby balance charger. A 600-1000+w one that accepts 9-49v, then a large 120v AC->48V DC power supply. Probably throw both in a toolbox with some strategic mounting and ventilation hole-sawing. Put a C14 plug inlet (like back of a computer PSU) and wire that to the power supply. Would allow monitored and balanced charging at custom voltage and current, the second of which will come in handy powering it from my generator at high elevation where it has significantly less umph.

Anyway, sweet. My average discharge is 29ah peak summer and 22ah thus far in September with things cooling off - running my 62qt dual zone fridge. Means if these cells aren't junk I should enjoy them for many many years to come if I can call them full at a storage voltage of 3.4v or less, and barely make a dent in them overnight. Thanks for thread.
Which one did you buy and how much did it cost? Trying to decide which one I want as well.

Thanks
 

hour

Observer
Which one did you buy and how much did it cost? Trying to decide which one I want as well.

Thanks
If you mean BMS, the one I linked two posts earlier by Deligreen. If you mean active balancer, QNBBM 4S Balancer/Equalizer. If you mean battery, the one that has 195ah in the thumbnail but says 195ah 190ah not 200ah not 100ah whatever these dorks do. But if you're getting batteries you may wish to wait for my report after testing, or order the CALB batteries from the link Shamus posted for the same price. Ultimately option #2 (CALB) is probably the safest bet.
 
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