That could actually be where I went wrong in the past. I’ll make sure to store the items with a decent charge. Thanks :)

I have a percussion massager that will only hold a very small charge after about 6 months (it was a Christmas present). I assumed I stored the battery improperly because I’ve only used it infrequently since then. Maybe I’m wrong about that, I really don’t know, it might have just been cheaply made. I’ll try the ~40% charge for my other devices to be on the safe side. Thanks for the tips :)

I assume these batteries are lithium ion because it’s all random consumer grade items from e.g., Amazon. I’ll check to see which ones have a battery life indicator on them and charge them all to as close to 40% capacity as I can get. Thank you for the advice :)