I have a relatively new, October 2013 manufactured Bosch 49-850B that came on my CPO 08. For the second time in the last 2 days, the battery has gone dead enough so the car can't be started, but not completely drained so the PCM/lights won't turn on. I've left the car parked for a few days before, and this has never been an issue. Is it time for a new battery? And if I put in a battery outside of the dealership, will this affect my CPO?

Thanks!

 

You can have your battery tested for free at any auto parts store, but I'd be looking at your alternator as the culprit. Your battery either can't hold a charge (bad battery) or it's not getting a charge (alternator, usually). Check to make sure you have good contact at the terminals. It would be highly unusual for a bank in your battery to be dead so soon, but it's possible. I just changed out the ORIGINAL battery on my 2000 Mercedes S500. It was 14 years old and had 165,000 miles on it, made by Bosch.

 

what accessories do you have plugged in? Phone charger? Bad alternator is a one time deal, you have about 30 min of power then you are dead and you will probably kill your battery, without all those details its hard to say though.

 

I had a similar problem and it ended up being the engine ground strap.

 

Ahh interesting, thanks guys.

I had it jump started and drove around for about a half hour after. The car didn't die and started ok after that a couple of times, and then died again the next time I needed to start it.

I have a Dension 500S BT and a phone charger, but nothing else. I'll get it diagnosed at an auto store, good call, thanks .

 

Possibly a bad relay in the alternator. If it doesn't close properly, battery will drain rapidly. Requires replacing alternator. One possibility among others.

 

I had an aftermarket iPod stereo input thing installed in my range rover, they installed it so it was draining power from the battery all the time, (I did not know this) and never used it so when my battery went dead and a new battery was put in and same thing happened again they figured it out.
Lesson learned lol

 

I was thinking it was the Dension too, but I'm not sure if it's possible with the following scenario - I was away for the July 4th weekend so the car sat for an entire week (from Friday to Friday) in the garage.

When I went back to start it up again, it fired up without any issues. Drove it around for a little bit, made a couple of stops to banks and gym, and it wouldn't start up outside of the gym. Had it jump started, drove for about 40 minutes, parked it in the garage again.

Went to start it the next day, started fine. Drove around a bit, made a couple of stops, no issues. Took it to the gym at night, I noticed it starting slow but did crank over. After the gym, it wouldn't start up and had to get jump started again.

Any thoughts? Won't be able to take it in to get tested until Tuesday .

 

Seems use causes drain, ergo, charging system failure. Probably should be easy to see if it's a dying/malfunctioning alternator. That would be my primary look.


Whatever the cause, bless your CPO.


Best

 

That's it, you're 0-2 at the gym. I'd say somebody wearing nuthuggers is sucking all the energy from your car.

 

Check ur heating and ac to see if both work as should. A failed heater control valve can draw power and drain battery. I had this issue on two German cars. A power drain test will usually tell you how much power is drained and fulling fuses can reveal the source of the drain too. Anything over 15 milliamperes with doors closed will drain battery in 2-4 days

 

You can leave your car for months without any issue - if it's charging properly and something's not shorting or causing a drain. It looks like it's time to take it in and have a test done.