What causes car battery to keep failing?

I have a 1995 Chevy Lamina and it seems like the battery keeps failing. I got my battery replaced on 1-12, 2-27, 6-5 and this week the car has no lights and can't be started. I get these batteries replaced at Pep Boys free of charge. I tell them to let me know if anything else is ad and they just replace the battery. Obviously these batteries can't all be defective. Why do these new batteries keep failing on me and what is causing it to happen?|||Lots of possibilities. Alternator could be under-charging but this does not damage the battery. It could be overcharging and destroying the cells.|||Maybe something is pulling power while you're away from your car? A light left on? Something plugged in to the cigarette lighter? Or maybe your alternator (the car part responsible for recharging your battery once your car is actually started) isn't functioning properly?





Car batteries should last at least 2 years so you're right in thinking you shouldn't be having to replace them this often.





Maybe you could take it to a Chevy dealership or auto mechanic and tell them about the problem? It's hard finding a person who will actually believe you and try to actually find the source instead of just telling you to replace the battery, but if you try hard enough you should be able to find somebody skilled enough to locate the problem.|||Have them check to see if the car is overcharging the battery. If it is being overcharged, the fluid in the battery is boiling off causing premature failure. Oh, and I recommend that you take it somewhere else other than Pep Boys. An independent shop with ASE certified mechanics is best.|||Have your charging system tested. That many batteries is very unusual. Your alternator could be overcharging the batteries - not good - leads to battery failure. I would expect Pep Boys would have tested your system due to the number of 'free' batteries they've given you.|||You prob have a bad alternator(it keeps your battery charged) and pep boys is notorious for not checking things out. I think you should take it to a real mechanic shop. Or it could be bad conection but id bet that its your alternator. pep boys sucks!|||you better have the alternator and starter checked. it sounds to me like there,s a short and it,s leading back into the battery.|||constant voltage drain.you may have bad wiring or accesories wired in that slowly drain the power out of the battery|||bad alternator or wiring and or regulator