How to check if battery is dead?

[minieggroll]

Hello,

Lately, if I don't ride my GZ for 2 or more days, it has trouble starting. It will attempt to start but will not be able to. If I jump it through my car, it starts right up. However, if I've ridden the bike earlier that day, it will start right up by itself.

I'm guessing the battery is dead and won't hold a charge? How do I check the battery to see if it is okay or needs replacing? Do I check with a multimeter?

Thanks!