I just purchased a used car that appears to have a new battery. The seller says it’s new, AAA thought it was new. Auto parts store says I need a new battery. Why does my car have to be jumped each time before it starts? Should I keep starting it each day or should I just let it set dead for a week until my mechanic has time to fix it? I heard that a bad battery can mess up the alternator, so I’m concerned.
It might be that the cables connecting to the battery are not completely clean where they attach to the battery, They need to be removed and cleaned with steel wool, then reattached.
It certainly could be something else, but doing this is pretty easy, cheap and fast.
I had this problem on an intermitten basis with my ‘79 Fiat Strada. After determining it was not the battery (load test with an amp meter), dealer suggested a new starter, undeer warranty wasn’t my nickle so went ahead. Same problem. The cure was to tighten the ground cable on the engine side (it took the dealers’ mechanic who was from Italy to realize what was happening). Moral is: not only clean and tighten the battery terminal connector, also check the ground connection(s).
Maybe battery is not all that good, or it may be a drain on your system even when turned off, a problem with the charging system or it could be cable/connection problems (remember that each cable has at least two ends, check both Also note that cables can go bad internally. Someone should check it out hands on.
Yes a bad battery can overwork the alternator, and the other way around.
Maybe it’s not getting fully charged. Use a battery charger, get it fully charged and see what happens. The alternator isn’t meant to charge a dead battery.
Maybe it has another issue and this is partly why the seller got rid of it.
Any auto-parts store that sells batteries will test your battery (for free) and install a new battery if you need one…
if your existing battery will accept a charge, then perhaps your vehicle has a “parasitic load” that is draining it…Any decent repair shop can sort this out in a few minutes…
Even a new battery can get a shorted cell. Corrosion on the cables or loose cables can cause the battery not to charge. The battery and alternator can be checked at AutoZone for free.
“Auto parts store says I need a new battery.”
OK, why are you asking? I think you already have your answer. If you want a second free opinion, ask another parts store to test it again. Even WalMart does it. If the battery came from WalMart, they will go by the date sticker on it and give you a new one if it’s bad within the warranty period.
To everyone who has responded so far, thank you so much. Your information has been very helpful.