With car hot, battery won't crank engine

[Ken92SVX]

Has anybody had this same problem?

When I have been driving my car and it is hot, after I make a brief stop to run into a store, my car will not crank over. It seems to be related to if the fans were running when I shut the car off. Then a few minutes later I get back in and its like the battery is dead and won't crank over the engine.

The battery is only about a year and a half old (84 month battery).

If I wait a few minutes and shut off the radio, and let the seat belts finish their cycle then it may then crank over.

I do not believe this problem is related to an electrical problem, just a weak battery because the car requires a higher load than the battery can delivery.

I checked the acid level in the battery and all cells are full.

Does anyone else have a similar problem?

Thanks, Ken