[mikey G]

Quick question for you guys as my searches have not really answered my current situation. I recently stored my car for 9 months. (climate controlled, wheels off, jack stands, yadda yadda) However I did NOT disconnect my battery because I read many different things prior to storing on what I should/could/would have done. With that being said can anyone let me know what I should do to prepare for when I come home? Is buying a completely new battery my best option? I just want peace of mind because I am really limited on time when I get back and need to get my car moving asap. Anyone have any insight on my situation that can shed some light on my best course of action?

Thank you in advance!

-Mike

[mikey G]

For reference I had a buddy that is home from deployment before me go to my storage unit and the car would Lock/ Unlock after he connected jumper cables and lights would come on, however the vehicle would not turn over. Im assuming this is because the amps in the battery are not high enough to power the vehicle. Someone chime in and let me know what my best plan of action is. Should I get it towed to a shop? Bring a brand new battery with me when I get home and slap it in? Should he have tried to jump directly to the battery in the trunk and not the positive terminal under the hood?

[bmw325i]

Get a new battery. It probably won't hold a charge after being dead for so long.

[mikey G]

I've read multiple times that replacing the battery on my own will throw off the computer? Confirm/ Deny? Also what is the best battery for use with these e90's...ive done so much work on cars but this little problem is giving me a headache lol.

[GTKrockeTT]

you'll want to get the battery coded, but you can drive around with a new one temporarily.

[bmw325i]

http://www.e90post.com/forums/showthread.php?t=532315

[Three_thirty_I]

I would not even store a car for a few months with the battery connected, even my old vintage car gets the battery disconnected when not driven for a few weeks/months at a time. With modern cars there are so many electronics still drawing current, so it does not take long for the battery to be drained.

Since you are pressed for time, probably best to just buy a new battery and have it registered (coded). It has to be exactly the same type and capacity, so bear that in mind.

If it was me, I would invest in a good intelligent battery charger (something like a Ctek MXS 7.0 or so) and see if the recondition charging function would recover the battery. Also depends on how old the battery is to begin with. Don't have enough experience with AGM batteries (if your car has one of those), but normal lead acid batteries (my E90 has a 70Ah lead acid battery) can often be saved. Worth a try. Also, always always charge the battery from the jumper point in the engine bay - it is important to charge through the car's electronics for the IBS to be part of the process.

Hope you are able to get this sorted out.

[bmw325i]

Originally Posted by Three_thirty_I

I would not even store a car for a few months with the battery connected, even my old vintage car gets the battery disconnected when not driven for a few weeks/months at a time. With modern cars there are so many electronics still drawing current, so it does not take long for the battery to be drained.

Since you are pressed for time, probably best to just buy a new battery and have it registered (coded). It has to be exactly the same type and capacity, so bear that in mind.

If it was me, I would invest in a good intelligent battery charger (something like a Ctek MXS 7.0 or so) and see if the recondition charging function would recover the battery. Also depends on how old the battery is to begin with. Don't have enough experience with AGM batteries (if your car has one of those), but normal lead acid batteries (my E90 has a 70Ah lead acid battery) can often be saved. Worth a try. Also, always always charge the battery from the jumper point in the engine bay - it is important to charge through the car's electronics for the IBS to be part of the process.

Hope you are able to get this sorted out.

I would leave the battery connected with a battery tender if I was storing it for that long. Too late for that now though.

[hassmaschine]

A BMW will go dead in 3 months without a battery tender, 9 months is not surprising. My 25 year old E30 lasted almost 4, but the E90 is way harder on batteries.

[mikey G]

Thanks for the reply guys. I understand what a jackass move it was storing it connected, however, I heard conflicting things and I was on an extremely tight schedule prior to deploying. That being said, what's done is done and I am working on having it fixed as we speak.

[bmw325i]

Originally Posted by mikey G

Thanks for the reply guys. I understand what a jackass move it was storing it connected, however, I heard conflicting things and I was on an extremely tight schedule prior to deploying. That being said, what's done is done and I am working on having it fixed as we speak.

I wouldn't leave the battery disconnected when storing because you still might have problems after reconnecting the battery. When I changed my battery I had it out for about an hour and after reconnecting it I had to reset the steering angle sensor. I had an error and my turn signals wouldn't turn off after making a turn. That is why I think a battery tender is the best option because it will maintain your battery and you can leave it connected as long as you want.

[mikey G]

Hey guys, I forgot to update! So the car is GTG. I had a buddy that was home before me from deployment give the keys to a friend in our Euro Group. He took the car and replaced the battery for me and re-coded everything. Good as new! Thank you for reading....and I don't think there is really any good way to store these vehicles "long term". For a few months...yes...just keep the battery juiced with a tender. However more then 5+ months....yeah there are going to be issues you have to sort out when you get back. Im just glad I have friends that are there to lend a helping hand when needed.

[hassmaschine]

Get a battery tender. They're like $50.

[Three_thirty_I]

Main thing is you got her up and running again! Yep, a battery tender is the way going forward when she is being stored.

[Wilt]

LCI E90s have the stupid omission of a conventional key lock for the trunk...another dumb design decision by BMW! So any LCI which is stored for a very long time is best left with a battery tender connected to the jump points under the hood. Do NOT disconnect the battery and close the trunk of any LCI, as you cannot get back in to hook up the battery unless you energize the electric trunk opening line via the fuse panel connection with another battery!...It will NOT work to jump the LCI via the jump points in order to press the electric trunk release button inside, if the battery is DISconnected in the trunk!!!

[cdgatti]

Originally Posted by mikey G

Hey guys, I forgot to update! So the car is GTG. I had a buddy that was home before me from deployment give the keys to a friend in our Euro Group. He took the car and replaced the battery for me and re-coded everything. Good as new! Thank you for reading....and I don't think there is really any good way to store these vehicles "long term". For a few months...yes...just keep the battery juiced with a tender. However more then 5+ months....yeah there are going to be issues you have to sort out when you get back. Im just glad I have friends that are there to lend a helping hand when needed.

Mikey, glad things worked out for you and welcome back. You can store these cars as long as you want (battery wise) you just have to hook up an intelligent battery tender like the CTEK unit. 9 mos later and you would have come back to a battery better than you left!

[hassmaschine]

I closed the trunk of our E91 with the battery disconnected. I was able to reach the battery cable from inside, but just barely.. that sucked!

[Twoforty]

I expect to have a similar problem when I return to my car next week. 2012 325i euro.
The car has been laid up for 2 months with battery connected (original 4 years old).
Could not use a battery tender because I live in a block of apartments and there is no easy access to power point for the full 2 months.
I guess if its flat I can use a trickle charger overnight to try to get it up.
Don't like the idea of disconnecting the battery which is what I have always done on previous E30 and E46 cars.
Another pita feature of the new models.

[Twoforty]

Relief.
After 2 months laid up with battery still connected, no problem to start the engine.

[Wilt]

Originally Posted by E92 N52 325i Msport

Relief.
After 2 months laid up with battery still connected, no problem to start the engine.

0.45A per day * 60 days = 27A...battery capacity is far longer than that.

0.45A * 180 days = 81A ...risky business!