Help: 2005 545i Disabled after alarm or Car battery dead?

[jimbofish8]

Hello -- this is my first post on the board.

I have an 05 545i which I've kept mainly garaged and drive somewhat infrequently (2-3 weeks of driving every 3 months) as I'm not in town that often.

Two weeks ago I disarmed the car alarm using the factory key to place something into the car and opened the trunk. I then tried to lock and arm the car using the key fob, but it seemed to not have enough battery juice to do that as nothing happened. I then used my key placed it into the door lock on the drivers side to lock the car.

It manually locked -- but after a few seconds the alarm started going off. I went to find jumper cables to try to jump the car to give it enough juice to disable the alarm and reset itself. It took me 10-15 mins to find the cables, but by then the alarm had stopped going off -- probably because the battery had run out. Since the noise had stopped at least for the time being, I left to do other things as I was a bit in a rush. Unfortunately, I was not able to go back to the car for another week.

Last night when I tried to jump the car. I connected the battery cables (as i had previously done before) red to red underneath the positive plus box and black to the brace between the two towers in the wheel well. However, unlike previous attempts, no power seemed to be flowing into the vehicle. The dash light doesn't come on, interior lights doesn't come on.

I have two hypotheses at the moment: 1) the car disabled? I'm not sure if the BMW has some kind of auto-theft device in it that will cause it to not power-up 2) the battery drained passed its recoverable limit.

I'm thinking that its probably #1... I've been previously been able to at least get power in a vehicle that has been sitting for a very long time with a jumper cable. But, in this case nothing at all seems to happen.

Does anyone have any experience / insight into this?

[Dirty_Tool]

Its not disabled.... I think the battery is just very dead. If you dont have a battery charger then buy 1 and try charging it. You should also be keeping a trickle charger on the car if you drive as little as you do.

[jimbofish8]

Hrmm -- Ok. Thanks for the advice.

Any recommendations on chargers / trickle chargers? Or will just anyone do the trick?

Does the battery have to be removed to charge the battery? And do the charging clamps have to be applied directly to the battery itself?

[marti5]

Any charger will be fine ( not a power pack/jumper), If its a sealed batt make sure the charger will do sealed batts, some have a switch for normal or sealed, its better to remove the batt from the car , but you dont have to, you can charge from + and - terminals on the battery or the terminals on the car but this will take longer, as will charging on the car without removing the terminals as It will start using the power straight away for the alarm etc.

[Dirty_Tool]

Battery Tender


something like this is what you want in order to keep the battery from draining while you are not driving the car. You can get the optional cigarette lighter adapter which makes it really easy to hookup. BMW sells similar right through their parts dept and i think its normally around $50. its a good investment considering the cost of a new battery as well as the cost of having the dealership "register" the new battery into the vehicle's electrical system which is very important to do if the battery is replaced.

[jimbofish8]

Thanks guys, got it working now!

Will definitely purchase one of these Battery tender things to keep the charge going while I'm away.