Thanks to Ed G or whoever recommended buying a battery load tester. Bought one off of Amazon for 18.99 and it works great. Tested several loose batterys already.
One quick question:

Do you need to disconnect a battery that is in a car or tractor before load testing it??. I do not want to hurt any electronics in the car.???

I am sure I could read the directions, but that is just not the guy thing to do. TIA S.

I don't know if you are supposed to disconnect the battery, but I generally will disconnect it, charge it and then load test it.

Thanks Ed.
That is just what I did.
Works great. Thanks

my dad has an old battery tester and we have used it plenty of time in a car and my tractor with the battery still connected.