Hey anyone one have any problems with their battery draing while the cars off? I have a brand new optima battery installed about a month ago when my stock battey died. I know its not the battery because when I disconnect it from the car after I shut it off and check it for charge its fine then hours later its still fine but if I leave it connect to the car it will be almost dead after about 8 hours. Any ideas? The alternator seems to be fine as well because if I drive the car the battery is charged when test it right after I shut it off.

 

Oh and the radiator fan sometimes runs for a few mins after I shut it off but thats normal after a long drive and it shuts off after 5 min or so. I have nothing aftermarket electrical either just the stock HK audio and nav system.

 

Put a multi-tester between the power lead on the battery and the battery itself and see how much power is being drained.
(disconnect power cable, then connect the multitester to the batt and the cable... do NOT start the car)

Do you have any aftermarket accessories? Lights, Sat radio, Ipod, anything...

 

Electrical is the worst problems to diagnose... I had a 97 Celica ( I miss her ) that had developed a power drain... Its the reason why I decided to trade up to the mini I own now .

chpsk8 has the right idea, Usualy mechanics have and idea what component is draining based on how much is being drained. I'd post back those #'s and i'm sure someone here can shed light on where to look/troubleshoot!

Good Luck!

 

After you have done the above and confirmed that you have a drain on the battery go to the fuse box and pull each fuse, one at a time and when your power drain goes away you have found the source of your problem.

 

Thanks I'll try that tomorrow

 

Put an Optima battery in my boat a couple years ago and it did the very same thing. We checked everything and finally took it back and got another one and it worked like a champ. Brother had the same experience with one too. Go figure, everything checked out fine, it would be doing great, let the boat sit overnight and it was dead. The boat has a master switch to the battery too.

 

So I took it to the dealer because I could not find the drain and they proceeded to take every power module out and checked all the wiring as well as reprogramed the computer. No more drain. Weird I hope it does not come back.

 

Good deal. Too bad they couldn't' get a definitive answer for you. Hopefully it doesn't come back.

 

should have told them about the aux fan staying on after the car is off. YOU NEED AN AUX FAN.
also to check parasitic draw on a vehicle hook a multimeter up to the negative battery terminal and a separate good ground. disconnect the negative lead to the battery and the reading you will get after 16 minutes is in milliamps.