Testing Removable, Used Battery "Health"

[dodgy_b]

So I have a system of numbering and rotating any new batteries I've purchased but have some 18650's and Hopper batt's from exchanges.

Is it safer (and more economical) to just recycle and replace my batteries of unknown age or is it worth testing them and keeping some in rotation? Particularly the HL's.

What kind of device do I need to do this and what am I looking for during testing? Capacity, etc? Thanks!

 

[sickmanfraud]

The best advice I can give is to "test" the used cells in a compatible vape and record the statistics of each cell (how many sessions, how responsive and other observations you consider pertinent).

Any cells that are not up to the job should be discarded.