Jeep started up fine this morning. Drove to work. Started up fine when I drove to meet a buddy for lunch. An hour later it wouldn't start. Tried jumping it.... no luck. Luckily, there was a PepBoys 2 blocks away, so yanked out the battery and had it tested.... dead. What caused the battery to suddenly just die? Optima YellowTop only 2 years old this month. I'm not trying to start a whole "optima's suck" debate because tons of people I know use them for 4-6 years without issues, and some people hate them & have nothing but problems. So, I'm just trying to educate myself on general auto battery knowledge.... what can cause a battery to work one minute and then an hour later dead? I didn't leave any lights or accessories on either. Do batteries sometimes simply "just die"?

Thanks in advance for any help with my conundrum. -Mike

 

My '07 did the same thing without any warning. Battery was deader than crap! I was told it can just finally crap out all at once! I replaced mine and have had no issues.

 

My next step would be to check the charging system. It should charge the battery at around 14.1 to 14.4 volts.

 

It could have been a very old battery. Was there a date on it? Sometimes batteries sit around to long and go bad. Just take it back and get a new one. My optima has been great.

 

My voltmeter is displaying 13.8-14.2 with engine running so alternator seems to be fine. Maybe the fuel cell just crapped out. I bought a new battery... just figured I'd take this opportunity to learn/troubleshoot some more.

Thanks guys!

 

Sorry just reread that the battery was 2 years old. All my optimas have always lasted much longer than that.

 

Parasitic draw. Search youtube to help figure out how to trace it

 

Disconnect the battery negative cable, place multimeter leads between battery terminal and negative cable, set the multimeter on the mA setting and measure the amp draw with the vehicle off. The draw shouldn't be over 300 mA. If you are reading alot more of a draw then you have discovered a problem. Start removing fuses from the fuse block until the amp draw drops dramatically. That will be the circuit that is causing the problem. Then you need to determine what is fed by that circuit and start tracing wires and taking readings at harness connectors to narrow down the area that has the problem.