HamannE60

Hi guys,

I just recently lost all electrical power on my car being that I haven't driven it in almost a month, yea I know really stupid of me I was out of town. So I came back this friday and I noticed that when I opened the door that I had no electrical power my lights wouldn't come on and the gauges and idrive screen wouldn't either. So I rushed over to my local BMW service department and purchased a BMW Advanced float charger, I opened the hood and plugged it to the positive and negative ground terminals next to the engine. It has now been charging for about 2 days now and still no power comes on, I am afraid that if the power doesn't come back on after done charging that I will be SOL because I cannot open the trunk to get to the battery since the power is not on, and I cannot get my car out of the garage unless I get it towed perhaps to the BMW service center (last resort). So what I'm asking you guys if you think this is normal that the power has yet to come on and if the reason why is because the charger is still charging the battery and it hasn't reached 80% yet and then perhaps the power will come on. Or should I just hook it up to another running car for 30 minutes or so and then jump start it. Sorry for the long post and Happy Holidays!

ponnu

I am not sure which model (year) you have. If its E60, you should have a truck key hole. Use the key and open the trunk. Replace the battery with a new one.

HamannE60

I have a 04 530i. I wish I could open the trunk but I have a m5 trunk finisher on the lid covering the key hole and I don't want to have to rip it off just yet, but if the car is dead does the keyhole open the trunk?

As for the battery, I replaced it almost 3 year ago with an OEM one from the dealership I think it is rated at 110 AH so can these be recharged if they are discharged below a certain point? I don't know but if the car's battery is almost dead and slowly fed with minimal amperage 1.25 amps per hour (BMW Charger) will the car's power eventually come back on after it reaches a certain %? And is it possible since the battery is charging that the current being fed is disrupting the charge to the car's electronics and that's why their is no power, but once it is charged past 80% and I disconnect the charger the power will come back on? Does this make any sense? Hopefully an electrical engineer or someone can chime in? Thanks guys

DanL

That's a battery tender and it's intended to maintain a battery's charge, not to charge it. See if you can find someone with an actual battery charger or jump start it.

HamannE60

Thanks for your replies guys, I know the BMW Charging system serves it purpose for primarily battery tending but I read somewhere on another bmw forum, that these "Float Chargers" can also charge a BMW's battery sufficiently it just takes a lot longer, also I heard that it's bad for the car given the many electronic modules, sensors, and fuses to apply a high voltage charge to the car when it is sufficiently lower than a fully discharged battery below 70%. Many people have said to charge it at a slow amperage below 2 amps, as it is better for the car's electronics and battery. That is why as another later resort I will have to jump start it if the charger doesn't power it up. Just need to know if this is normal for the car's electronics to be totally dead when the battery is almost juiced out, or if someone else has run into this problem and tried this method or another, thanks guys!

tonyb635

As for charging the battery it might be that your charger will not charge it. My sons car has a slow sucking trickle and while he is in Afghanistan I just throw the charger on it every two weeks. At first I waited two months and the battery that is less than a year old was totally dead and would not even take a charge from my charger. I had to take it to Advance for a over night slow charge. All was ok after that.

HamannE60

Thanks for the your post, I wish I would've bought a faster trickle charger now that it has been taking forever to charge this battery (2 days now on the BMW charger). But, I have been hopeful being that on the charger it indicates that if the light is a steady red then it is charging the battery and their are no disruptions or problems with the current being fed to the battery. I wish I could do the same as you and take it to Advance Autoparts but I cannot gain access to the trunk right now since their is no power

HamannE60

Anybody know if when the car's electrical power is completely dead if the trunk opens if you insert the key into the trunkhole? The car's doors are all unlocked just the trunk refuses to open, do you think the trunk can only open if their is power?

I might just wait for another day or two to see if the battery is charged enough to see if the car's power comes back on if not then I have no choice but to jump it from the engine terminals, do you guys think that maybe a sensor or module or fuse is blown and that is why the power hasn't come back on or do you think when a battery is charging from a low state the power doesn't come back on until it reaches a stable state 80% or above?

Sorry for all the questions, thanks fellas!

turboawd

you should be able to open the trunk with the key.

in my experience,if a battery goes dead and stays dead for awhile, its toast and wont recover. especially if its an older battery.

i'd just get a new battery if i were you.

HamannE60

I agree just want to make sure 100% that the trunk will open with the key, can anyone confirm this? I don't understand why the car is all unlocked and the trunk should be too, but when the power goes off the trunk refuses to open, do you think the key just unlocks the trunk, in which case the trunk should be unlocked theoretically speaking since I always leave the car unlocked in the garage. And under normal operations the trunk pops open when the handle is pushed, I know for sure the trunk is unlocked I just want to make sure the key actually opens the trunk and not just serves as the unlock/lock trunk feature. I have a m5 trunk finisher on there and don't want to rip it off and then find out that the trunk still can't be popped opened using the key. Thanks!