As E-booger noted, voltage is not necessarily the sign of a good battery; only a quality load tester can determine if a battery is "good".
100% correct and did I chase my tail for about 5-6 hours a couple of weeks back on this. And I should know better
What tripped me up was I was mowing, jumped off to move a branch and didn't shut the PTO off so it stopped the engine. I jump back on turn the PTO off hit the key and NADA, zip zero. Thought it blew the main fuse. NOPE. Got my other unit towed it up to the shop. VOLTAGE was OK and having just started the unit 30 minutes earlier I NEVER EVEN considered the battery itself. I proceeded to chase my tail thinking something was shorted or one of the safety interlocks was causing the issue.
Chased it from the battery all the way to the solenoid/ starter. Every time i checked the V it was right at 12.5 or 6. I finally got lucky by leaving the meter hooked up and watching it drop to 2.4 volts with a decent load and then recover within about 30 seconds.
In over 50 years I have never had a battery just fail like this one did. As they say you learn something new everyday. i can guarantee you i won't get burnt by this one again
