[chentron]

planning my first EV conversion, is the moment to choose battery.
A guy sell me NMC battery recovered from a mitsubishi .
but I recently discover alibaba sellers LiFePO4 , with very good prices, very similar.
price very similar, a bit cheaper the NMC.
what do you think is better ?

 

[Moltenmetal]

My opinion only: NMC has higher energy density per unit weight and volume, but is more difficult to work with. I would not use it without a BMS.

LiFePO4 is very easy for hobbyists to work with- it is safer than NMC but still might be hazardous without a BMS- or you personally acting as your own BMS.

So it depends what you want- lots of energy density, or easier/safer use?

 

[chentron]

the NMC from mitsubishi outlander are 12.5 kg for 30volts x 40 ah , 30x127,5x12,5 , that means 10.77 kg/kwh

the LiFePO4 are 3.2x20ah for a pouch with 480 gr, 23x16x0.7cm , that means 7.5 kg/kwh . I still need to add the frame to contains the cells but it is not really higher density for NMC, at least for cells inside outlander.

I see in alibaba that NMC are really a bit lighter than LiFePo.

Weight and density is very important , but , What about the number of cycles for both cells.


I read about scam with consumer cells in ebay from china sellers. How reliable do You think are the sellers in Alibaba ?

 

[Solarsail]

I see in alibaba that NMC are really a bit lighter than LiFePo.

Weight and density is very important , but , What about the number of cycles for both cells.

I read about scam with consumer cells in ebay from china sellers. How reliable do You think are the sellers in Alibaba ?

I recently bought NCR18650B Panasonic 3.4Ah from Alibaba and tested half of them and they were all genuine. For cell only, these weigh 3.80 kg/kWh, and 1.6 L/kWh (hex 0mm space) or 2.2 L/kWh (square 2mm space). These are the densest cells you can find on the market, only exceeded by LG 3.5Ah cells.

As said above, LFP is more forgiving, while NMC gives you the highest density. Please see:

http://www.diyelectriccar.com/forums/showthread.php/18650-13s10p-project-48v-x-34ah-188618.html