Battery not charging

Is there a relatively simple way to test the charging system, of my Craftsman or Husqvarne, to make sure it is OK ?

Simplest way is to start the engine and let it run at idle speed. Attach a volt meter across the battery and take a reading. Should be between 12.6-13.2V. Bring the engine up to 3/4 throttle and watch the meter. It should climb to 13.6-14.9V. If you get these readings, your system is charging. If not post your engine numbers and I will try to find a manual to do a systems check to locate the problem.

Thanks, As soon as this cold wx passes, will get mower running