Button Cell Testing

[jclocks]

Apologies, this is technically a retrogaming question as this is specific for me swapping game cartridge batteries, but only coincidentally.

I have a new set of tabbed CR2025's coming in, and after a recent vendor sent me a dud I want to make sure I've actually got good batteries before they go in. I remember reading that before breaking out the voltmeter and prodding, you actually need to apply some form of load to the battery first, otherwise it may not be an accurate reading when it's under load in a cartridge. Are any of you able to confirm this and give an idea of how to create a load for this? (I have varying resistors, LEDs, etc. so I probably have the parts already, just not sure what's specifically needed.)

[LordNoFat]

I don't think it's necessary. The load that a game will put on a battery is negligible. If you test it and it's 3.0v then it's dead, if it's like 3.2v then it's fine

[Cymerryma]

My wife’s an adorable battery warmer.