lithium polymer batteries safety and storage

[Jim]

So at the end of each summer drone flying season what is the best suggested battery charge level for safe storage. I saw some where that you should only charge your lithium polymer drone batteries to about the 50% level to avoid any possible expanding damage. Is that correct.  I had fully charged my Eachine EX4 2 batteries at the end of last year's season, and they both expanded a lot and pushed off the case cover. Okay thanks.

[dronemaniac]

I had heard that as well somewhere, 50%, not full charge

[Jim]

So since my Bugs 4W folding drone has a battery charger with 4 lights to indicate charge level, I think I will try for 2 lights on solid with the third one blinking. Also I found out how to connect a multi meter or a battery tester to this drone battery. With really thin wire ends put on the test probes, it can fit into the row of battery contacts. And then touch only the first and the last ones with polarity correct by trial and error, and it shows charge level okay.