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What specs to match when looking for replacement cells?
#1
What specs should you compare when sourcing replacement cells? I need to find something similar these https://secondlifestorage.com/showthread.php?tid=1684 since it seems like exact replacement cannot be found.
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#2
It's pretty much the most common lithium battery out there, and used in most laptop batteries. You just have to watch out for the different types of lithium based batteries out there. The most common are these laptop batteries, 3.6V-3.8V nominal and a discharge of around 3-400mA (or .1C). You also have high discharge NMC type batteries used in power drills and e-bikes where it's high drain, they're typically 3.7V and their nominal discharge are higher around 5000mA or 3-4000mA (1C). You also have LiFePO4 type, and these have a 3.2V nominal. These three are the most common and yours is the first kind so you have a wide variety of replacement to choose from.
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#3
Depends on what you are replacing them for. If you are just replacing single cells to bring an existing pack to life, you should make sure the capacity is as close as possible as this could cause the bms in that pack to work harder to maintain balance. Ie: replace a few cells in a laptop pack. Most only have 2 cells in parallel and imbalance can happen very easily if 2 cells are higher or lower by any significant amount from the others. Powertool packs would be another example.

However, if you are replacing "all" the cells in the pack, then it doesn't really matter overall as long as your amp ratings are close. If the cells that were in there are rated for 1A discharge/charge, then you don't want to replace them with cells that are designed for 500mA discharge/charge. Best to go up a little if you can't find the exact match.


More info on what you are actually wanting to do would help answer your primary question a lot easier.
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#4
I had someone ask if I could affordably replace the 30 cells in a dead e-bike battery, so it would be replacement of all 30 cells. I was hoping to replace them with the same one that were already in there, but can't find any, so I was looking for something similar or better like you had stated.
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#5
Maybe focus on capacity (mAHrs) & discharge rate being same or better as the original pack.
Get new cells close to each other in capacity.
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