Consequence of Battery Failure

[HumbleNewRider]

I've heard that motorcycles don't have an alternator, like cars have, and that the motorcycle will therefore stop running if the battery dies while you are riding.

Is that true?

I have a 2008 GZ that I bought about 4 months ago. I'm the third owner, and the battery is the original one. If what I was told is true - how do I know when to replace the battery to avoid the motorcycle leaving me stranded in the middle of a ride? It has been working flawlessly so far.

thanks....