I have an 05 Coupe and for the life of me I can't figure out what's draining the battery. I turn everything off when I put it in the garage and yet the battery dies overnight. Once I jump it and let it run for a little while the alternator recharges it and it's fine.
I can't seem to turn the tow alarm off and I have a sneaking suspician that's keeping my computer from going to sleep. I left the car unlocked last night and I hope that did the trick, but if not, does anyone have any other suggestions of what to look for?
When I called the dealer he said, "Maybe your battery is dead", to which I replied", I just bought the car from you 4 months ago I would hope you wouldn't have sold me a car with a dead battery." Silence on the other end of the phone.
Soooo, any ideas will be appreciated. The car only has 24,000 miles on it.

 

Your battery likely has (at least) one bad cell. These things happen.

If you're not still under warranty you can take the battery to pretty much any decent auto parts store and they can test it for you.

If you need to buy a new battery there are a few good threads on what fits, what works and what is an exact replacement.

 

I still have the extended warranty so I hope that covers it. I saw the thread you're talking about and it seems these batteries start at around $113.00. It's not the money, it's the damn principle at this point. I bought it from a dealer as a "Certified" pre-owned vehicle and it would hardly be "Certified" if they sold it to me with a bad battery.
Thanks very much for your response.

Have a great Memorial Day weekend.

 

Its possible for a battery to go bad in 4 months time. I wish I would get 4 months warning when my battery goes bad. It could go bad overnight.

To ease your mind try this, drive the car or get the battery fully charged how ever you do it. When you park it at night, disconnect one battery terminal. The next day, connect the battery cable back up and try to start it. If possible, leave it disconnected for two days and see what happens.

There will be a certain amount of draw on the battery which is normal to keep the electronics working.

Sounds like a defective battery, but also to confirm you need a simple amp meter to see what draw you have while the car is shut off. I would be glad to check mine and we can compare.

Also if you take your battery to have checked, which is a very good idea, be sure it is fully charged or they won't be able to give you a solid answer.

James

 

Also if you keep recharging your dead/defective battery with your alternator, you may need to replace that soon.

James

 

Is this still the original battery ??
If so it is likely 5 years old now and low mileage really has nothing to do with battery life.
A dead battery can not be sufficiently charged by just the alternator either.
In fact it is a strain on the alternator to even run the car on a weak of low battery.
Get the battery a deep charge on a charger and follow some of the advice James gave you here.

 

I had the battery checked and it was definitely time for a new one. You would think a reputable dealer would've made sure to have a new battery installed in a "Certified" pre-owned car, but I'm just happy that's all it was.
$160.00 installed wasn't too bad in my book.

I appreciate everyone's responses and I hope you all have a great holiday weekend.

Any Long Islanders here?

 

Glad you got your trouble fixed. I don't like to side with the dealer, but they had no way to know the battery was going to only last 4 months.

James

 

On an 05 if you wanted a new battery when you bought the car, you should have asked for it so the dealer could price it into car when he sold it. Chances are the battery was good when you bought the car and I would think the dealer has fufilled his obligation to you. A batter is very much like a light bulb, it can go bad in one day. Great that you got it fixed for the cost of a battery.

 

I'm also glad ya got the problem resolved.
I recommend that anyone here with an '04 or '05 model with the original battery considers replacing it even if the one you have is currently working fine.
Why wait for it to fail before replacing it ??
I replaced mine in my '04 and it was still working but now I know I should be set for 5 more years.

 

Thanks again for all the replies. I'm really glad I found this forum. I hold no animosity toward the dealer, they've actually been one of the best I've ever done business with and I know they couldn't predict the battery failing in 4 monthis.
As I said earlier, I'm just happy it took only the cost of the battery to fix my problem.

I hope you all have a happy memorial day.

 

Also search the forum for heat seaters or check on mbworld.org in the C32 section for the same thing. The seat heaters are known to go bad and draw electricity causing your battery to drain. Mine is original and sits a few weeks in between driving, still going strong for 2 years.

 

heat seaters....

 

Good catch I meant meat beaters. Here's another dyslexic fx owner. LOL.

https://www.crossfireforum.org/forum/359021-post3.html

 

Just make sure there isn't a control module still "talking" when the car is off. That's called Parasitic Draw" When the car is off and the control modules are no longer talking via the CAN network the draw should be in the area of 30-40mA. Unhook your negative battery terminal and complete the circuit with an ammeter to read your parasitic draw. If there is a draw, it will still happen with a new battery. I think it was said before too, batteries and alternators usually fail hand in hand, the alternator is stressed to charge a poor battery.

 

The alternator will fail if it is overloaded carrying a dud battery. The solution is to dump the battery when it gives signals of weakness, headlights dimming at idle, odd happenings with the car systems etc. Why risk a few hundred dollar item because of a hundred dollar item.

 

Attention - Attention. Xfires cook the front cell of the battery each time you park hot. Merc SLK's have a compartment around the battery to prevent this. I have now simply wedged a wad of soft white fluffy stuff, called cortel I think, taken out of an old speaker box, in front of my new battery. If you can look inside your cells, you will see that the front one is going white from sulphation. The only cure for that is to drill into the connector bar and separately charge just that front cell. A new battery is easier. Parked drain is 13mA unlocked - theoretically 34 weeks to flatten the 74Ahr battery.
This advice should have been on a RECALL !!! Regards, Jim in New Zealand, where Chrysler wanted $US600 for the genuine battery !!!

 

I seem to be having the very same problem, bought an 07 LTD brand new lass fall from a dealer. Parked over the winter with a couple of start ups with no problem. I drove it about 2 weeks ago without an issue. Yesterday I went to start it and it was completely dead! I jump started it and drove for about an hour, but tonight tried to fire it up and had the same issue, dead as a doornail. It's still under warrantee with 1900 miles, so I guess I'll jump start it and drive it straight to the local dealer (before they close their doors!).

Car looks great, to bad it won't go anywhere....

 

I have had power seat buttons get caught and do in the battery, real sneeky, Woody

 

Do the heated seats draw from the battery once they are engaged? I don't ever plan on using the heated seats, so does that make me pretty safe? No need for me to worry about battery drainage?

Monty