Car battery shorted? Can anyone explain what happened?
 

Parked briefly to go in bank, and I came out and as I was starting the car, the car suddenly died. No slow crank, no dimming, it just died. Pressing the start button did nothing, then I waited 5-10seconds and the start button light came on but nothing else like dash/odometer.

I quickly googled car battery suddenly dying, not a slow dying battery. Came across a battery being shorted and how sometimes hitting the battery with a small hammer could work. I tapped it lightly with my phone(with rubber hard case on) a couple times, went in and lo and behold it starts like new.

WTF happened? Why and how does a battery short? How does tapping it fix it? This battery is 3ish years old from costco, do I need to worry?

Very curious about this phenomenon.

Do you just have dirty ass terminals?

Does your battery require water to be added?

never heard of tapping a battery. loose dirty terminal maybe repositioned it enough by tapping it to get good contact.

costco tho - march that battery straight up to the counter and get a new one anyways

Yup probably loose terminal.

It fell asleep, you just needed to tap on it to wake it up!

Sounds like bad connection on one of the terminals.

Sounds like loose connection I had something like that happen to me after I changed a brand new battery, I didn't tighten the connection enough. It would drive fine but sometimes won't start mysteriously, randomly took for ever to diagnose.

You googled how to fix it but not how it happens? You need to get the good, Google. :troll:

Lead acid batteries use plates and cells, if the plates deteriorate and touch the next cell, there's a potential for a short. That said, it's more than likely a bad connection....or aliens.

Unlikely a battery short. Most likely corroded or dirty terminals. Even though your terminals might look clean id take them off, clean and retighten. I had this happen to my summer car a few times i put my battery back in. Once I lost all electrical mid drive when I went over a bump! Turns out it was the positive terminal even though it looked clean and was really tight.

@jmac, no it doesnt need refills.

Hmm, it was dark so I couldn't really see the state of terminals. I guess that makes more sense because tapping the battery and having it work blew my mind.

What kind of car? If it has push button start I assume it has some kind of keyless go system, I wouldn't be surprised if the security system got confused and you leaving and re-entering cleared it up.

I had something similar happen in the past, turned out my positive terminal was loose.

possible a dumb fucking rat was at the wire,you never know on the streets..check your wires...or what these guys are saying,a nut went loose and disconnected from your battery.

also possible one of the wires got exposed and are touching together,check where you think one might've grinded down to the metal,this happens tho you notice it cause your car or truck will sputter like hell while driving and act normal again.

i voted for the aliens...

anyways, without knowing some facts, like battery voltage at the very least, hard to say if it was "shorted".