CR2032

Found a couple CR2032 batteries inside a couple junk Chinese flashlights. These were the cheap, translucent shake lights which are supposed to charge from a weight sliding back and forth in the body.

Interesting reading on the Harbor Freight MM . . dead batteries are 3v but only 0.1mah on the battery tester. Another dead CR2032 from Japan is only about 2.1v and reads 1.7mah.

Is there a way to tell if these 3v batteries are rechargeable?

Do they need to be, or is the needed recharge current so low/feeble that that it doesn't matter? (Actually, I don't see how any charging is going on when the thinly wound coil isn't connected to anything!)

PS - Anybody done a project on one of these shake lights? Has a cheap plastic aspheric lens that really concentrates the beam when placed in front of an XML.