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Discussion Starter · #1 ·
I'm re-doing my battery pack, and I've unleashed quite a few sparks in the process. I'm not going to use all the modules I have, and I'd like to use the "best" ones for the car, and keep the rest as spares.

Is there a simple way to test an individual (2014 Leaf) module for condition/strength? All cells have a reasonable 3.8-3.9V, but that doesn't mean anything. It would be great if it didn't involve fully charging and discharging 48 modules for hours, but hey...
 

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I'm re-doing my battery pack, and I've unleashed quite a few sparks in the process. I'm not going to use all the modules I have, and I'd like to use the "best" ones for the car, and keep the rest as spares.

Is there a simple way to test an individual (2014 Leaf) module for condition/strength? All cells have a reasonable 3.8-3.9V, but that doesn't mean anything. It would be great if it didn't involve fully charging and discharging 48 modules for hours, but hey...
Battery reconditioning is about getting more out of your existing cells, not giving them the gift of eternal life.
Just happen to hover around something interesting on reconditioning. You might want to take a look
 

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Discussion Starter · #3 ·
Oh I'm not trying to recondition anything, I'm just trying to pick the best modules from the ones I have. I just want to make sure I didn't fry any of them with my impromptu welding...
 

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A dummy load that maintains CC and precisely times the drop from your definition of 100% Full SoC, down to your definition of 0%

gives you an apples to apples actual mAh capacity rating.

Assuming they all started off the same, % of original actual mAh is your SoH, State of Health.

Could rig the same with resistors or light bulbs, but then precise accuracy depends on your EE skillz.

Wattmeter / coulomb counter is less accurate but good enough for many.

A 0.5C discharge rate means under 30min per cell, but gives a lower result than 0.1C

If you run multiple testers at once, cross-reference calibrate so they all return parallel results.

Also standardize temperature.

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ESIR is another good tool, but much harder to standardize, IMO only use as supplementary to SoH.
 
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