Four times in the last several months, our 2006 (2.4) has experienced a sudden, total discharge of the battery. Starting fine, running fine, then a few minutes or next day later - totally dead, but jump starts fine and goes until the next time it decides to happen.

Two days ago, when it happened again, I decided to go ahead and replace the battery. Corrosion (the white dusty buildup) had been occurring rapidly on the positive clamp/terminal, and putting out just 10 volts.... though I didn't really think this would solve the problem.

Sure enough... just two hours later, went to start it and the new battery was totally dead. This is the first time the problem has shown up again immediately. It's only happened a few weeks apart before.

Is this a known problem for this car - recommendations?

Thanks,
Mark

 

These types of problems can be very difficult to track down.

Two hours is very short time to drain a new battery due to parasitic load!

Was the battery completely dead? As in you turn the key and nothing happens or perhaps the car just has dash indicator lights?

It is possible for an alternator (alt) to have diode fail. The result is the alt does not put out full power to keep the battery charged. The battery then slowly discharges even when driving.

Do you think the battery was fully charged when the engine was turned off?

A failed alt diode can also a drain on the battery when the engine is off.

Does this car have a third party installed wireless remote or alarm system?

There was some issues with factory remote/door lock computer draining the battery. However the drainage took many days to drain the battery, not hours.

The blower motor for the heater/AC has had problems coming on uncommanded. This was an intermediate problem.

Let the car sit 15 minutes with every thing off. Then go around the car (including trunk and engine compartment) and look/listen for signs that something is on.

Include items such as heater blower, electric mirror, door locks, trunk light and glove box, etc.

To drain a fully charged battery in two hours would take a high amps usage item. A door lock, trunk or glove box light isn't high enough.

When doing the check you can open up the relay boxes inside the engine compartment and feel the individual relays for warmth from operation.

If the problem is constant you can connect an amp meter between positive battery terminal and battery cable then read the current flow. Normal flow with all items off is low at 20-35 milli-amps.

If the problem is intermediate then finding it may take some time.

Mean time might consider disconnecting the negative battery terminal when parking for any length of time.

 

Thanks. A little more information:

The time before three days ago, an interior light was left on all night - so this might have been the actual cause.

Both times before that, the radio was on for just a few minutes with the engine stopped. Went to start again and had dim lights, but wouldn't turn over. This was very unusual, for sure. All three of these times, got going again with a jump start.

This last Friday, the car was driven, parked that afternoon - everything fine. Saturday morning, I went to leave in it and the battery was completely dead, no lights at all. Being Christmas Eve day, I didn't feel like dealing with checking out the battery, etc. myself and possibly replacing it, so I just called AAA to come and look at it.

After he got there and finished, he said he checked the starter, alternator (which I replaced myself about four years ago) and the battery. Battery was showing to be a little weak, so I said to go ahead and replace it - at least get that out of the equation. He cleaned things up, installed the new battery, and the car started right up. I just turned it off again and left it parked. About two hours later, went to go leave and totally dead - not even lights.

No aftermarket alarm system. Haven't noticed the blower coming on by itself, but couldn't say for sure. I'll take a look at it tomorrow, following your suggestions, and see if I can come up with anything. Any additional thoughts appreciated.

 

Are you 100% sure the battery was dead? Sometimes the electrical system is the problem.

Check the batteries amp rating. A two hour drain to dead on a new battery is a LOT of amps! A radio or interior light is not enough amps to drain it this fast.

There has been incidences of headlights/running lights not turning off or coming on. If the headlight setting is now Auto, when done driving might turn to off.

When you have the amp meter, use the volt meter selection to check battery voltage.

Place the positive meter probe on the "+" battery terminal and negative on the "-" terminal.

Do this engine off after sitting for 20 minutes. A fully charged battery will have a voltage of 12.7-13.2v. This is what you would expect after driving.

Something around 12.4v is 75%, 12.2v 50%, 12.0v 25% and lower is battery discharged. If after driving the battery voltage is lower then the fully charged range, the alt may not be working properly.

If you can't wait 20 minutes to check the voltage, place a load on the battery such as headlights and blower, etc for 20 seconds. Then with ign off check battery. Should be no lower then 12.5v.

Check voltage with engine running. Should be between 13.2-14.8v indicating the alt is working.

If problem happens again check battery voltage to make sure it really is dead.

 

This might be a really dumb suggestion but are the main earth cables making a good connection. Any big earth cables to the car body with bad connections might be worth checking. removing, cleaning, retightening.

 

Here is one thing you can do to make sure there is no current loss after the ignition is off. You need a current meter to test this.

After the engine ignition is off, disconnect the negative battery cable and measure the current between the negative terminal of battery and disconnected battery cable. If there is current measuring more than 1 mA, you have a short somewhere.

You would think the short would trigger a fuse to trip. Fuse will trip only if the current loss is higher than the specified current amperage of fuse.

If you find current loss at the terminal, you need to do the same for every fuse you have to find where the short is.