Best Cells for first time DIY-er

[Justkeepitsimple]

Hi everyone. I would like to build my own LIFEPO4 battery. Probably from prismatic cells. 12 volt. ~300 to ~[600 Amp hour worth. I’ve read a lot of builds and understand the basic materials and tools involved.
Battery cells, cell insulation, cell compression, battery cables, terminals and crimpers.
Adjustable DC power supply for initial top balancing, BMS with desired features and cell series configuration.

What is the best quality LIFEPO4 cell I can buy these days? Is at all possible to purchase cells that are not made in China? I know they’re the leader in the manufacture but I have my reasons not to go with Chinese cells if it’s at all possible.

What is a good quality adjustable DC power supply? I don’t need a huge one. ATM all I can ever imagine using it for is initial top balance of lithium cells. So I want to buy just the right size for the job. I don’t see myself looking to build an x ray machine or Tesla coil and don’t need more tool than I need taking up limited workshop space.

Look forward to hearing experiences and opinions asking some questions and learning some more.

 

[42OhmsPA]

As far as I know these are made in Japan.

New LEV60F 3.2v 74ah Lifepo4 Power Cells

If you buy 6 they will ship in the original case. Otherwise we will repackage them safely into a custom box. They are Lithium Energy Japan cells model LEV60F. These cells are overstock and were originally intended for luxury vehicle 12v lifepo4 starter batteries. Cell Specifications Nominal...

batteryhookup.com

@Daddy Tanuki you ever hear of them?

I'd pick up any basic 30V 10A bench supply for ~$50 from eBay, Amazon, etc.
Battery Hookup also has some higher priced power supplies.

 

[42OhmsPA]

Just saw your other thread about those cells.
I guess you don't want them...
I don't agree with your thoughts about balancing them and charging them.
Charge to ~3.5V/cell and start balance ~3.42V/cell.
Any decent BMS will be able to be programmed just fine.

 

[Justkeepitsimple]

I got excited about those Japanese cells initially but after digging very deep into the abyss (not much first hand info from people using them) there are three potential problems with them:

1) They’re a “starting” battery. They use LIFEPO4 chemistry but internal electrolyte/ cathode-anode designed for 600 amp surge current @ 1500-2000 cycle life. May not provide desired Solar storage cycle life due to cell material engineering that provides such high surge currents.

2) Most of the affordable ($22 ea) cells available are very old surplus stock (2020-ish), lots of calendar aging in unknown climatic conditions. Verified storage new cells are closer to $50/ ea.

3) Top cell charge is 3.5 V per cell not the usual 3.65. Cells require programmable BMS (not that big an issue) that hold at not higher than 3.5 v per cell for balancing and appropriate high voltage cut off.

I guess the LEV60F cheap enough for a diy tinker project. My desire is to build a quality pack for as secondary off grid energy storage solution. We are a no grid access situation. Have our big home solar system on lead acid. Want a small secondary independent system (think a small workshop 700 watt daytime continuous).

 

[Wattson25]

Hey there! For high-quality prismatic cells, you’re mostly looking at Chinese manufacturers like EVE, CATL, or CALB, as they dominate the market with reliable, high-capacity cells (300–600Ah). Finding non-Chinese cells is tough—most are made in China due to cost and scale. Some companies like Winston or GBS might source cells from other regions, but availability is limited, and they’re often still Chinese-made or rebranded.

For an adjustable DC power supply for top balancing, a compact 30V/10A unit should do the trick for your 12V setup. Look for something reliable with good reviews—doesn’t need to be overkill since you’re just balancing. If you want to learn more about DIY battery packs, can check out this article: https://www.docanpower.com/BLOG-and-FEEDBACKS/how-to-diy-a-lithium-battery-pack

 

[Justkeepitsimple]

Just saw your other thread about those cells.
I guess you don't want them...
I don't agree with your thoughts about balancing them and charging them.
Charge to ~3.5V/cell and start balance ~3.42V/cell.
Any decent BMS will be able to be programmed just fine.

I want to like them. However I am not confident they will meet my expectations. Hoping to get at least on the lower end of LiFePo4 cycle life ~4000-5000 cycles at 70%dod).

That and my understanding is each series string of cells needs it’s own independent BMS. A BMS can only correctly monitor/ balance a single series string of cells. Correct? In that case to get 400ah of 12 volt battery I need like (5) or (6) 74 amp hour batteries each needing its own BMS. Where if I start with a ~300ah cell I can get 600ah of twelve volt battery with two batteries and only need to buy two BMS’s

 

[42OhmsPA]

Well I'm running 32 EVE and 16 REPT cells from Docan, 16 Envision AESC cells from 18650 and have 36 more REPT cells from Docan waiting on Class T fuses and some free time.
Attached is the power supply I've been using.

 

[42OhmsPA]

That and my understanding is each series string of cells needs it’s own independent BMS. A BMS can only correctly monitor/ balance a single series string of cells. Correct?

That is correct.

In that case to get 400ah of 12 volt battery I need like (5) or (6) 74 amp hour batteries each needing its own BMS. Where if I start with a ~300ah cell I can get 600ah of twelve volt battery with two batteries and only need to buy two BMS’s

That is also correct but you also need to keep in mind the max current of each BMS. If you only run 2 packs with 100A BMS on each you'll be limited to ~2.5kW load. You also need to consider C Rate for the cells you choose. Personally I like to keep mine well below 0.5C, hence the multiple packs in parallel.

 

[OzSolar]

Look forward to hearing experiences and opinions asking some questions and learning some more.

Just my 2 cents...

DIY doesn't make near as much sense as it did just a few years ago. It's most certainly not as much fun as the nearly endless made for YouTube videos make it seem. Plus that ~$75 BMS has risen to over $400 in just the last few weeks. (others will be along shortly to argue but I'm just trying to offer my experience) Me? I'm a master electrician with an industrial engineering degree and 35 years of commercial and industrial wiring experience and a shop full of tools. My first battery sucked and I had to buy new tools which I really hate doing now a days.

We all know you're going to do it, so pick up a Victron Smart Shunt and pretty much any $80 or less 0-10A/0-30V power supply from Amazon or eBay.

I'd start with some of these since they don't need compression and they are cheap.

Used CALB CA100 3.2V 100AH LIFEPO4 PRISMATIC CELL

These batteries were all recovered from battery packs that were removed in working condition. They are not capacity tested but they are guaranteed to have good voltage and no swelling. We include the bolts as well. Capacity: 100AhHeight: 216 mm (8.5 inch)Width: 67 mm (2.64 inch)Length: 140 mm...

batteryhookup.com

 

[42OhmsPA]

Good advice on the shunt.

Not here to argue, I did that enough at work today....

BMS https://www.docanpower.com/usa-stoc...ction-for-solar-lifepo4-batteries-by-jiabaida

 

[Justkeepitsimple]

Those CALB cells look very interesting. They really don’t require compression?

Just my 2 cents...

DIY doesn't make near as much sense as it did just a few years ago. It's most certainly not as much fun as the nearly endless made for YouTube videos make it seem. Plus that ~$75 BMS has risen to over $400 in just the last few weeks. (others will be along shortly to argue but I'm just trying to offer my experience) Me? I'm a master electrician with an industrial engineering degree and 35 years of commercial and industrial wiring experience and a shop full of tools. My first battery sucked and I had to buy new tools which I really hate doing now a days.

We all know you're going to do it, so pick up a Victron Smart Shunt and pretty much any $80 or less 0-10A/0-30V power supply from Amazon or eBay.

I'd start with some of these since they don't need compression and they are cheap.

Used CALB CA100 3.2V 100AH LIFEPO4 PRISMATIC CELL

These batteries were all recovered from battery packs that were removed in working condition. They are not capacity tested but they are guaranteed to have good voltage and no swelling. We include the bolts as well. Capacity: 100AhHeight: 216 mm (8.5 inch)Width: 67 mm (2.64 inch)Length: 140 mm...

batteryhookup.com

How do you access that page from batteryhookup main page? Only way I was able to find them was through the link you included here. Are there other options I may be missing by navigation somehow?

Edit: never mind: because they are sold out

 

[frankrudis65]

Hi there, the only long time review I've ever seen was based on the Winston cells.They seem(ed) to be very robust build,heavy propper plastic isolation and they still had ca. 92% cpacity after 15 Years.If they are still build to that quality,I don't know....Regards Frank

 

[upnorthandpersonal]

DIY doesn't make near as much sense as it did just a few years ago.

Definitely not for 12V systems. For large 48V systems you can still save a ton though.