Looking for affordable 40-50Ah Lithium-pouch cells

[Zotto]

Hey all, I am looking to have a 7s connection of 3.7V (~26V nominal) lithium-pouch cells batteries, most likely NMC chemistry, but I am having difficulty finding affordable prices for 40-50Ah capacity. My budget is relatively high, and I found a promising vendor of XALT energies but they are charging 75$ for 1 3.7V, which is fine, but they require me to buy 16 cells at a time as per UNDOT regulations or something to that effect. Could anyone point in a direction to finding more affordable batteries, or telling me a better approach to my problem? Also, I found another distributor, Kokam, but I cannot find any information on how much the batteries cost or where to even buy them, they don't respond to my customer service emails... If anyone has dealt with them before, I would appreciate some advice.

As of right now, I am trying to drive 6 BLDC motors, rated at 6.6A, for a rocker-bogie drive train, I think that should require at least 40Ah, to guarantee an hour of run time, including running additional circuitry on board, including cameras and MCU's. Is the 7s approach fine? Any suggestions/advice would be greatly appreciated. Thanks!

 

[jonescg]

I don't know of many reputable sellers of 40 Ah pouches, and Kokam is probably the only one springing to mind. EIG sell their 20 Ah NMC pouches, and of course Farasis does a 30 Ah pouch.

You can always put a couple in parallel - that's what I've been doing with 5 Ah pouches to good effect, although it really does depend on your dimensional constraints.

7s is a good number - it puts the terminals on the opposite side so you can conveniently put another in series next to it.

 

[Zotto]

I don't know of many reputable sellers of 40 Ah pouches, and Kokam is probably the only one springing to mind. EIG sell their 20 Ah NMC pouches, and of course Farasis does a 30 Ah pouch.

You can always put a couple in parallel - that's what I've been doing with 5 Ah pouches to good effect, although it really does depend on your dimensional constraints.

7s is a good number - it puts the terminals on the opposite side so you can conveniently put another in series next to it.

How much do the Farasis 30Ah usually cost?

 

[jonescg]

Don't know - email sales@farasis.com and ask. Farfle works for them, so he might be able to chime in if he sees this thread.

 

[Zotto]

Don't know - email sales@farasis.com and ask. Farfle works for them, so he might be able to chime in if he sees this thread.

Okay, will do

 

[Hillhater]

I dont know if Kokam trade in cells anymore since Xalt is the new name for what was the Dow Kokam battery division.
https://www.xaltenergy.com/index.php/about/company-background.html
You could consider using Leaf cell 66Ah modules , they can be sources for ~ $100 each and are effectively 2s , 7.4v modules .

 

[liveforphysics]

Generally speaking, the larger the pouch, the more costly the mfg equipment by a greatly increased non-linear scaling factor. This is why you rarely see low $/Wh in big format pouches, however it does make an elegant and clean pack design done well. Packaging and handling pouch cells to make a pack that survives in the wild from bare cells is a lot of work, I would buy the most recent generation LEAF modules and leave them sealed in the cans, used LEAF cells (or other used EV cells) are as cheap as you can get.

 

[Harold in CR]

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