What could be draining battery every other day

What is your question?

3 interstate batteries in 3 years. 1 heavy duty interstate battery. Auto start installed about 3 years ago. Battery problems since! Mechanics tell me nothing wrong, just making I drive the car at least every other day. When I have no reason to go anywhere, I don’t. I have never ever had a car like this! I hate this car. Would trade but has no trade value. I think that common sense tells me something is draining the batteries to absolutely to dead status.

What makes this problem better or worse?

Charging battery for at least 2nhours

How long has your 2000 Nissan Sentra had this problem?

3yrs. Since auto start was installed