2001 Dodge Intrepid - Battery Problem?

The first thing I'd do is pull the battery and see if it's bad. Unfortunately, when you do that you'll discover that it's quite a bit harder to get at than most cars, since it's down in the wheel well (still not really hard, but harder than the "standard" location). The location is cooler, so I seem to change the battery much less frequently in that car than anything else I own, but it makes up for it when I do.

If the battery is good, you start unplugging fuses when the car is off to find out which circuit has the drain. Then you start tracing that circuit...

I agree with Joe that the first thing to check is the battery - go to Advance or Autozone and have the battery tested.

My guess is that the battery just won't hold a charge for long. Even a moderately bad battery can hold a charge for a few minutes - but let it sit for a few hours and it will have lost its charge. (Joe is also right in that ic *could* be something in the car draining the battery, but if the battery is several years old, it is likely the battery).

You say you guess you should have checked on problems they have before buying it. What problems in particular are you concerned about? Does it have the 2.7L or the 3.2 or 3.5L engine? I own two Concordes - mechanical the same car as the 'Trep.

Oops.

Should have said "...mechanically the same car..."

Likely the battery is failing, particularly if it's the original. The good news is the batteries outside the engine compartment (I believe it is in your car) last much longer. My wife's 2001 Sebring still has the original battery, going strong. I no longer will trust it in cold weather though. With previous cars that had the battery beside the engine, the battery lasted 5 years max.

The most likely suspect is the battery itself. These days most batteries fail suddenly and completely, but a good percentage still fail exactly as you describe- retain charge for short periods but won't sustain a charge overnight.

It is possible to test the off-cycle current draw of the vehicle too. You connect an ammeter in series with the battery and the car, wait for all the normal "housekeeping" functions that the computers do after engine shutdown to finish, and then see what the residual current draw is. It should be very small- micro-amps to a few milliamps. If you're not electrically inclined, a shop can do the test for you.

Right on. FWIW, according to the 2002 LH car FSM, IOD (Ignition-off Discharge) current should range from 5 to 35 mA (sorry - I don't have the 2001 FSM - would expect the numbers to be similar). The FSM says that a battery in OK condition should hold a charge for at least 20 days at that rate.

I'm not sure what you mean by 'all the problems.' I have a 1999 Intrepid and still love it, very easy to maintain. The 2.7L engines do have some issues however, the 3.2L and 3.5L engines are fairly trouble free.

Like others said, it's probably the battery. If you are still running on the factory original battery, it's well past its typical lifetime anyway. The battery is fairly easy for a shop or store to test, however changing the battery takes a bit more effort. The battery is mounted low which contributes to a typically very long 8 year lifetime, but makes replacement more involved.

Another cause might be if the brake lights are sticking on. That's very easy to check too, just take a look after you get out of the car.

A very easy method to check if it is the battery is to disconnect the Negative Ground Post under the hood immediately after you park the car and leave it overnight. The next morning reconnect the Negative Ground Post and if the battery is good, the car will have power and start.

Greg

Good point Greg. I had forgotten about that - common occurrence in the LH cars. If that's his problem, easy to fix too (calibration procedure on the brake light switch).