Testing 18650 "cells"

Oct 15, 2026 1 Replies
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I've rescued a metric buttload of Samsung INR21700-50E (5000mAh 9.8A 3.6V), NiB.



Obviously never used.



So, how to test if they are still useful? Will a small trickle charge suffice to top them off? Or, do I actually need a genuine charger?


Charge with a current-limited power supply.

Discharge into a resistor and datalog.

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