Battery discharged when stopped, now no start even with jumpers

[Introextro]

Hi,

A couple of weeks ago i started getting the "battery discharged when stopped". Curiously right after the sunroof got stuck. Anyway now the car is completely dead in the garage and won't start with either a jumper box or with a friend's car. The engine does crank a little but dies quickly. Any ideas before i ask a tow truck will be highly appreciated.

[Freude_am_fahren]

If the engine turns over, the car is not completely dead. Please describe more detailed what is happening. Does the dash come on? You say that the engine dies quickly. Does the starter just turn the engine over or does it fire and then turn off?
Where do you hook up the jump box or starter cables? What is the voltage of your battery?

[Introextro]

Originally Posted by Freude_am_fahren

If the engine turns over, the car is not completely dead. Please describe more detailed what is happening. Does the dash come on? You say that the engine dies quickly. Does the starter just turn the engine over or does it fire and then turn off?
Where do you hook up the jump box or starter cables? What is the voltage of your battery?

The dash was coming on, on its own but no longer. With the jumper box the lights come on after a couple of seconds stay on for 10 seconds and then turn off and nothing happens. The starter half turns and then stops. Today there was not a single light on or any switch working. Thanks!

[Freude_am_fahren]

Either the car doesn't get enough power or the power disappears somewhere in the car. It seems more likely to me that the car doesn't get enough power.
Replace the battery (or both, I don't know what kind of car you have exactly) and see what happens.
Sometimes when the battery is dead and can't hold any charge, you have to hook up a lot of external power to start a car. You could hook up two cars to yours if you have them available, one directly to the battery and one to the jump contacts under the hood. Also make sure your jump cables have enough contact.

What is the voltage of your battery?

[Introextro]

I haven't checked the volts on the battery, i haven't opened the screws yet. It is a 50i. I did try to jump start with another car but it didn't happen. We tried for 5-7 times. Thanks

[Freude_am_fahren]

Sometimes one car and a jump box won't cut it in a situation like that. Try to hook up more cars to it and/or get a new battery.

[Introextro]

Can i try a jump box and another car at the same time? Or two boxes? I am not sure if that's safe(?) for the car but let me know if you think otherwise. Let me try to get a jump start tomorrow, else I'll have it towed. Thanks a lot

[Freude_am_fahren]

It is safe to connect several jump boxes and/or several cars, you can hook up two cars and two jump boxes at the same time for example. Just make sure that you hook up everything correctly and that black and red never touch each other.

[Introextro]

Thanks, really helpful

[Clifton]

If the single or pair of 12v are old, replace them. Just make sure to let the car go fully asleep and follow instructions (lots of threads on this)

Battery swap will save you the tow and a trip to the dealership not to mention keeping more of you money

[Qsilver7]

I'd be VERY careful hooking up jumper cables directly to the battery. You can end up damaging control modules. The positive terminal in the engine bay supplies "connected consumers" with a "protective line" (see info below about the positive engine bay terminal).

Those "jumper boxes" may not be supplying enough power to start your X5. You'd be better off using jumper cables connected to a donor car...and using the CORRECT terminals in the engine bay. If you're not using the dedicated negative jump start terminal in the engine bay...this may be a reason your past attempts failed. {If your car's battery is deeply discharged...it could take a good 5-10 minutes to get the battery enough power to start.}

Lots of owners have connected the negative jump cable to a nut on the shock tower or some other metal...thinking it was a true ground...and charging or jumping didn't work. You should use the dedicated negative terminal that is shown in your owners manual. Some times it's a hex bolt...but sometimes its a little pin-like thingy in the engine bay.

[RED_Y_]

Originally Posted by Qsilver7

I'd be VERY careful hooking up jumper cables directly to the battery. You can end up damaging control modules. The positive terminal in the engine bay supplies "connected consumers" with a "protective line" (see info below about the positive engine bay terminal).

Those "jumper boxes" may not be supplying enough power to start your X5. You'd be better off using jumper cables connected to a donor car...and using the CORRECT terminals in the engine bay. If you're not using the dedicated negative jump start terminal in the engine bay...the may be a reason your past attempts failed. {If your car's battery is deeply discharged...it could take a good 5-10 minutes to get the battery enough power to start.}

Lots of owners have connected the negative jump cable to a nut on the shock tower or some other metal...thinking it was a true ground...and charging or jumping didn't work. You should use the dedicated negative terminal that is shown in your owners manual. Some times it's a hex bolt...but sometimes its a little pin-like thingy in the engine bay.

This is probably the most common mistake people make with BMW, trying to hook cables to the battery directly and damaging IBS unit or not being able to start the car. I wish more people follow the manual.