I just replaced a perfectly good 4 1/2 year old battery on my F150 because we go long distances towing with it and I was just being conservative. Sucks being stuck on a trip especially for a battery that is hard to find like my truck battery is.
It is called a surface charge, and the battery is dead and gone, will never hold a charge. They just show a normal reading but it is not thru the whole battery. Have had this happen to me a few times. The plates have shorted out probably from crud building up in the bottom.
I have done that on a few ocassions, nothing worse that getting stranded with a bad battery. On my boat I have extra batteries to fall back on, but not my vehicles. When I get my oil changed, they normally do a battery load test ( yea they want to sell me a new battery) but it does give some warning when one might be going!!
I have one of those cheap load testers I linked before.
Years ago when I was running 4 trucks and 2 cars I would buy a new battery for my bass boat every Spring and then put the battery from the boat into which ever vehicle had the oldest battery. Shows that by fishing was more important than my business.
