Degrading outside a voltage range and soldered batteries means they’re talking about the lithium ion or lipo parts of this chart.

I’ve seen several “present credentials” demands here lately. I find it a bit odd.

Well, thats because I am a theorist who lately had to look at industry technical engineering websites about matters that academics dont care about and I find them to be mostly hearsay and heuristic garbage. I need to know whether your “credentialed” experiences can be written off.

Citation: search for the terms “self-discharge”. I dare you to find something less kosher than the wikipedia page. I already find the wiki page less than kosher.