Help please. My E53's battery's drained after parking for only a few days

bulkwarrior · #1 12-03-2012, 07:38 AM

Help please. My E53's battery's drained after parking for only a few days. This has never happened before. When I tried to charge it with a charger overnight, the battery is still not charged. I do notice every time when the charger's charging, the driver side headlight turns on and when it's not charging the light goes off. Maybe that's the reason the battery's drained and not charging properly. Does anyone know why is this happening since the head light is in the "auto" position and should not turn on by itself when the car's off. Also the passenger side headlight does not turn on.
Thanks.

jgold47 · #2 12-03-2012, 09:32 AM

I would start checking cables 1st to make sure everything is tight I would also have your batter tested at your local auto parts place. You dont mention what type of e53 you have, how old it is, how many miles, etc... you also dont mention how old the battery is.

BMW batteries tend to do strange things when they start to go.

if a new battery doesnt make it go away, I am out of ideas, thats a strange one.

bulkwarrior · #3 12-03-2012, 09:40 AM

My X5 is a 2006 4.4i. I'm trying to troubleshooting the problem by removing the fuse for the headlight and then try to charge the battery. From how long it takes to charge the battery i can figure out how good the battery is. But the main problem now is I can't open the trunk lid because the battery is totally drained. I had to access the fuse box first. Will get another car later today to jump it and see if that works.
Thanks.

TerminatorX5 · #4 12-03-2012, 09:46 AM

the headlights are not supposed to come one when the engine is off, and it is obvious that your engine is off, when the light comes on...

The lights will come on from the iBus command, you can turn on/off each individual light in your car by sending a specific command on the bus - since your battery is dead and is laying on its deathbed, chances are that improper voltage level in the system causes the iBus to act unexpectedly, in your case activating the headlight...

You need a new battery

bulkwarrior · #5 12-03-2012, 10:41 AM

Thanks terminator! I guess you are right. I have a portable battery booster. Just connected it to the charging ports and voila the headlight was off and the battery is charging correctly. I'll wait till it shows fully charged and see how much capacity is left with this battery. In case I need a new battery, what's the group size I should get? Thanks!

Qsilver7 · #6 12-03-2012, 11:37 AM

Quote:

Originally Posted by bulkwarrior

... In case I need a new battery, what's the group size I should get? Thanks!

The battery group sizes to shop for are:

49 / H8
95 / H9

In certain instances you may find a battery that has a number that's off by one digit...like a 47, H6, H7, 93, or 94. Again, price check and look at the specs...sometimes a 49 class size battery may have more reserve capacity than a 95...but the 95 will usually cost more.

Here's some examples of Autozone batteries in the group sizes listed above (not an endorsement, just examples of what's available):

You can also check your battery's voltage if you unlock your OBC and run TEST 9 with the ignition in position 1 (engine not running). The best time to do this is on a cold engine or 2 hours after running the engine...this gives time for any surface charge to deplete (from being recently charged up by the alternator/charging system) and shows a more accurate state of the battery's voltage.

At 11.89 volts...the battery is at 0% state of charge. It can still illuminate interior lights & radio etc from the reserve capacity etc...but may not have enough juice to start the vehicle...and strange electrical gremlins can occur (as others have already stated).

Below are the instructions on how to UNLOCK the OBC so you can run TEST 9. You can also click the link below to see the description of each of the 21 TESTs that can be accessed after the OBC has been unlocked:

http://www.cardomain.com/ride/313409...series/page-6/

TerminatorX5 · #7 12-03-2012, 10:48 AM

i forgot, i think it was 92 or 93 - just check local autoparts store.. i consider battery to be a commodity, so the brand name does not matter as much... in my opinion..

bulkwarrior · #8 12-03-2012, 10:52 AM

Thanks, again I'm in 100% agreement with you. When I shop for batteries, I just pay attention to the cold cranking amps and the price. Nowadays they are probably all made in some asian country anyway. I have a smaller car which need a battery replacement last year. I went to local walmart, didn't find the exact match(they sold out) so I just bought a similar size battery and it worked great so far.