[Spaceman]

Hi guys,
Just posted the same question at bimmerfest forum as well, but here's the question:

I will be leaving town for 2 weeks straight. I read somewhere that BMW are meant to be driven every couple of days or the battery will be drained. Something to do with all the I-drive electronics or stuff thingy-hicky (not very technical sorry!) So if I leave for that long, do I come home and be greeted with a dead car that won't start? I also heard that it may be dangerous to jumpstart a car, that it will damage the sensitive electronics, but rather I should invest in a battery charger.

So, what should I do to prep my car before leaving?

Any help is appreciated!

Thanks

[E90Fleet]

The E90 includes a Intelegent Battery Sensor, should the battery drain down to a level where there is just enough pwer to start the engine left, the system will cut off all sources requiring power untill you put the key in the car

So you will always have enough power to start the car


But it shouldnt drain that far down in just 2 weeks

Just take the car for a nice long drive before you leave to make shure the battery is totally full when you leave

[David328M-Sport]

although it is not the same, i have left my e36 and e46 in my garage for about 2 weeks a few times while my family and i went on holidays.

i had no trouble starting the car after that time.

i trust it will be the same for the e90.

enjoy your time away.

[jhbodle]

Originally Posted by E90Fleet

The E90 includes a Intelegent Battery Sensor, should the battery drain down to a level where there is just enough pwer to start the engine left, the system will cut off all sources requiring power untill you put the key in the car

So you will always have enough power to start the car


But it shouldnt drain that far down in just 2 weeks

Just take the car for a nice long drive before you leave to make shure the battery is totally full when you leave

Really? That's so cool!

[Jason]

Originally Posted by E90Fleet

The E90 includes a Intelegent Battery Sensor, should the battery drain down to a level where there is just enough pwer to start the engine left, the system will cut off all sources requiring power untill you put the key in the car

So you will always have enough power to start the car


But it shouldnt drain that far down in just 2 weeks

Just take the car for a nice long drive before you leave to make shure the battery is totally full when you leave

Remember though when Nathan had to use BMW Assist when his battery was drained from leaving his parking lights on? Does the battery sensor only detect certain components being on? Here's the thread if you don't remember.

http://www.e90post.com/forums/showthread.php?t=1399

[skimo]

Leaving an a trip for 8 weeks...same rules apply? Would it be wise to disconnect the battery?

[E90Fleet]

Originally Posted by jwocky

Remember though when Nathan had to use BMW Assist when his battery was drained from leaving his parking lights on? Does the battery sensor only detect certain components being on? Here's the thread if you don't remember.

http://www.e90post.com/forums/showthread.php?t=1399

Think it only works when the car has been totally switched off and locked, leaving the lights on makes the car think you need them on

Will try and find out more

[E90Fleet]

Originally Posted by skimo

Leaving an a trip for 8 weeks...same rules apply? Would it be wise to disconnect the battery?

8 weeks is a long time, i would disconnect

[mc68386]

If they actually have this battery saver technology, it doesn't work very well. I showed up at my dealer a few weeks ago to test drive a 330, and he said we couldn't drive it because the battery was dead. Apparently it had been sitting in the show room and not been driven in a while.
They tried to quick-charge it, and that failed to. I ended up coming back the next day - he said they ended up putting a new battery in.

[romeo26]

i let my e30 sit for over 4 weeks when we were on vacation, and it started right up!!
if you disconect wouldent you have to put in a code somewhere to get the radio or something workin?

[freeman]

i think you will be fine,just make sure the battery is fully charged before you leave.
I once left my E46 in my garage for 3 months when I were on vacation.when i came back,it started right away.I also checked tire pressure,the result is perfectly normal .so you really don't have to worry about anything.just enjoy your vacation. :rocks:

[Spaceman]

Thanks for the info guys, I will definitely take the car out for a nice long drive before leaving..

I think I read somewhere in the car manual about not putting the car into "Park" but rather put it in "Drive" when parking the car for extended periods of time. Not sure if this is necessary... although in Park, there's an amber LED right next to the P that stays on..

Any ideas?

[evoq]

What is the best way to disconnect the battery.

Why BMW and other car companies don't place a switch near the battery to disconnect it without removing any cables.

This also would be helpful when you need to repair something in the car.

Also it could be nice to have a display near the battery to see how much percentage the battery have, that display could be nicer in the main display, but a mini display near the battery would be helpful in some cases and very cheap for car companies, right now if your battery is very low on power, you can't know how much battery power is left.

Also I don't understand why the car companies don't place a monitor to check the percentage of the battery to avoid not starting the car, when the battery is less than 60% or the needed amount of power to start the car, then all the accessories stop working, why would anyone wants to leave the lights of their cars until the car won't start, or hear the radio for long hours without turning on the engine?

The only car company that thinks in this problem is Rolls Royce, they place two batteries on their cars to avoid not starting the car if you leave the lights or hear the radio for long hours.

[wk]

My damn E90 has its battery drained mysteriously (no lights on, car properly locked) within 7 hours. Only 400 miles!

[firstkill]

evoq MBZ also has 2 batteries on some of their higher models...

I just left my e90 for 2 weeks without moving.. no problem on start up

but i dont have comfort access, that to me would drain the most for sitting... and i dont have the alarm with the blinking lights.

~fk

[wk]

Mine has both comfort access AND alarm.
But car was only parked for 7 hours before battery went dead.
No, no lights on and iDrive was off as the car was locked from outside.

[FeeBear]

I can safely tell you that I put my baby on ice for the more than 8 weeks without turning it on and it was fine.

Fee

[billgti]

Originally Posted by evoq

Why BMW and other car companies don't place a switch near the battery to disconnect it without removing any cables.

This also would be helpful when you need to repair something in the car.

because disconnecting is not a hard job at all and u probably want to make sure there's absolutely no electricity going thru. think of it this way. is it safer to immerse an electric appliance in water with the plug off or with the the plug in and switch off.

anyway back on topic, i've left my previous car over 3 months and it started without a problem. i don't think u have anything to worry about at all.