Mr. Li 3.2v 40ah Lifepo4 cells from Aliexpress - recommendation and testing


Solar Addict
Jun 4, 2021
Hi everyone.
Just wanted to share my experience so far with this seller and the cells.

Some background: I'm building a DIY 24v 8S Lifepo4 pack for my dad's mobility scooter, to replace the two 12v AGMs.
I know that there are other forums for this, but I have learned alot from this forum and it seems you guys are the Lifepo4 experts !
My use case is a bit different than those DIY super duper wheelchairs they are building.

Anyways, current configuration are two 33Ah 12v AGMs in series, which my dad has to replace about every 2 years because of degradation.

I won't elaborate now on all the constraints and design decisions for this pack. I will probably do that on a separate post that will document my entire build.

But for now I will just say that the main constraint was size: I have to fit the battery in the existing compartment, which has limited space.
These empty battery boxes are the same size as the AGMs:

So I was looking for the highest capacity 8S configuration that would fit battery boxes that are the same size as the AGMs.
Unfortunately I couldn't find one box that fit that space, so I decided to do two boxes with 4 cells in each, but both would be part of an 8S 24v setup, with 8S BMS, running wires between them (incl. balance leads).

Thats when I found these MR. Li Lifepo4 cells on Aliexpress:
3.2v 40Ah Lifepo4 cells
For some odd reason the seller changed the listing to 30Ah, but when I bought them, they were listed as 40Ah. I think maybe the seller ran out if stock of the 40Ah (maybe I ordered the last batch...) and was just to lazy to make a new listing, so he edited the existing one and updated with 30Ah. Also, you can see the pictures in some of the reviews, that have the 40Ah cells, as stated on the cell label in the pictures.

Anyhow, I got 12 cells from this seller.
I ordered 12 and not just 8 because as we know, some sellers don't package them properly and you can get a few cells dented. Also, I thought that if one or two cells were under capacity, I could just choose the best 8 cells.

I was super skeptic to buy these from Aliexpress, but as they were the perfect size and capacity, I had not much of a choice.

I did communicate with the seller beforehand, making sure he could ship to the Middle-East without problems.
Shipping was as stated on the listing: $84.
I also asked if they were grade A and the seller said they were. I don't think they are manufactured by any of the big Lifepo4 manufacturers, like EVE, CALB or Lishen, because I couldn't find the same size anywhere else.

I did take some precautions as I learned from other posts in this forum: I paid with PayPal so that in case of a dispute or scam, I would have an extra layer of protection.

So I was skeptical, but long behold, a month and a half from ordering, they finally arrived!
They came in two separate boxes (6 cells in each) as I agreed in with the seller, in order to keep shipping costs down. The packages came a few days apart, but I think this was a local logistics issue.

They came in perfect condition, packaged with tons of foam (pics are after I moved them around in the box to count them):
First batch:

Second batch:

There was no bulging of the cells (I wouldn't expect any as these are tiny compared to the cells used here by you guys for energy storage) and they have a QR code intact, printed on the aluminum casing (although not laser engraved).

The first batch came with one cell under voltage (2.15v) but all other 11 cells came at around 3.23v
Not perfectly matched, but good enough...
I slowly charge that low cell up, and I'm starting to test to see if it's OK.

For now I charged 2 cells from the first batch, and did a capacity test on those two:
Amazing! 41Ah each !
I was almost sure I wouldn't see above 35Ah (and would still be happy), but this really surprised me!

I started doing a top balance charge for 6 other cells.
I am using a step down converter (WZ5020L) connected to my PSU in order to pump more amps, as my PSU is limited to 10A.
The CC/CV step down is limited to 20A, but I'm running it at 19.5A, and put a little 12 fan above it (enclosed in a plastic box) for better cooling, as the 5v fan inside cooling the MOSFETs is pretty weak.


That's it for now. I will update on testing all the other cells too.
Hope you enjoyed!

A shout out to MR. Li - THANKS!
I hope I wasn't just lucky, but it seems that MR. Li is a good seller.


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Solar Addict
Jun 4, 2021
Just an update on these cells:
All 12 cells were tested and got above 40Ah capacity!
Pretty cool...

I also forgot to mention that the seller provided 12 busbars, flange nuts and washers.

I'm not sure what material these bus bars are made of, but they look like aluminum, or tinned copper maybe.
They are pretty thin, but I think they should be able to handle a 80A load easily (as these are small cells anyways).

Now I'm getting the cells prepared for installation in the battery boxes.

For compression I used thick double sided adhesive tape between the cells, and they are enclosed in this yellow fiberglass like stuff that is used by battery manufacturers.
The tape will act as compression because the battery box will hold them tight. I chose to put the tape vertically between the cells, so that there would be an air gap to allow heat to escape.