What’s the difference between 32700 and 32650 battery?

Hello all,

Im in the process of rebuilding my Aims 12v 100ah battery that failed a few weeks ago. I noticed the most of the batteries in it are labeled as 32700. I also noticed some that were 32650. What is the difference in these two batteries? I was a bit surprised to see that.
I was able to buy a new battery case and a 12v 100 ah BMS. Using #6 wire I reconnected the BMS to the battery and to the terminals.
I hooked it all up, connected the 3000 watt pure sine inverter and plugged in the heat gun. I ran it for about 20-30 minutes. It was peaking at 110 amps. It seems to be working great. The BMS was barely warm to touch. It also charges at over 30 amps now. This battery never did this before it failed.
Im going to add a desiccant pack this time and do the best I can to seal it up so it doesn’t breathe. Hopefully this time it won’t fail due to condensation shorting out the BMS.

Don.

That relates to the format of the cell. 21700 is the cell format Tesla developed to use instead of the 18650 cells.
21 = width of cell in mm, 700 = length of cell in mm. These formats are typically NMC / NCA Lithium ION. Recently, some companies have started producing 21700 LFP cells which now just adds to the confusion. Of course other chemistries are also looking at various formats to meet specific needs, so variants will continue to appear.

Thank You Steve. That makes sense. Seems odd they would mix the two in the same pack.

Don.

the 2 first number are diameter, and 2 next = length and last 0 indicate a cylinder.

Thank You for that.

the additional 5 millimeter could indicate also there is a protection circuit in the cell.
wikipedia state that the following
"Commonly-used designation numbers indicate the physical dimensions of the cylindrical cell, in a way similar to the system used for lithium button primary cells. The larger rechargeable cells are typically assigned five-digit numbers, where the first two digits are the (approximate) diameter in millimeters, followed by the last three digits indicating the (approximate) height in tenths of millimeters"