[zazzi]

Hello Folks,

We are doing some body repairs on a 2021 M2. The car has been sitting here for about 4 months now (waiting for some back ordered parts from BMW). The battery went dead and now we cannot start it. Jump doesn't work either - no power in the dash when we put the jumper on. Can't open the trunk to look in to the battery/fuses due to lack of power on the car. Can't hook on the scanner either.

Anybody faced similar issues? Any help would be appreciated.

Thanks.

[///M TOWN]

Originally Posted by zazzi

Hello Folks,

We are doing some body repairs on a 2021 M2. The car has been sitting here for about 4 months now (waiting for some back ordered parts from BMW). The battery went dead and now we cannot start it. Jump doesn't work either - no power in the dash when we put the jumper on. Can't open the trunk to look in to the battery/fuses due to lack of power on the car. Can't hook on the scanner either.

Anybody faced similar issues? Any help would be appreciated.

Thanks.

Crawl through the backseat to the trunk to gain access to the Illuminated triangle that will allow the trunk to be popped open manually

Get a Ctek battery tender and Run the battery through the maintenance profile, maybe that the battery is savable

Once you've done that you'll know 100% if your battery is actually toast or not

[F87source]

Originally Posted by ///M TOWN

Crawl through the backseat to the trunk to gain access to the Illuminated triangle that will allow the trunk to be popped open manually

Get a Ctek battery tender and Run the battery through the maintenance profile, maybe that the battery is savable

Once you've done that you'll know 100% if your battery is actually toast or not

You don't want to run maintaince cycles on an AGM battery it isn't good for it.

First I would probe the battery or underhood terminals with a multimeter, if you are way too low in voltage (<11V) I would say the battery is probably toast.

If it is not too bad you can try the battery tender, and if you leave it on AGM mode (snow flake mode) for 24 hours and you get nothing, then the battery is dead. Also remember to charge from the underhood ports never directly to the battery.

[///M TOWN]

Originally Posted by F87source

You don't want to run maintaince cycles on an AGM battery it isn't good for it.

First I would probe the battery or underhood terminals with a multimeter, if you are way too low in voltage (<11V) I would say the battery is probably toast.

If it is not too bad you can try the battery tender, and if you leave it on AGM mode (snow flake mode) for 24 hours and you get nothing, then the battery is dead. Also remember to charge from the underhood ports never directly to the battery.

Just charging it will help

Typical body shop scenario

[F87source]

Originally Posted by ///M TOWN

Just charging it will help

Typical body shop scenario

Not if it is discharged too far, theres a point where the battery will not be able to recover.

I think if you discharge below around 11V and there is a chance the battery will not last very long afterwards, and if you go below 10v maybe 9v there will be a point where it is too far gone for a recharge.

[///M TOWN]

Originally Posted by F87source

Not if it is discharged too far, theres a point where the battery will not be able to recover.

I think if you discharge below around 11V and there is a chance the battery will not last very long afterwards, and if you go below 10v maybe 9v there will be a point where it is too far gone for a recharge.

Sounds like it's completely trashed then

No surprise after 4 months of abuse

[zazzi]

The problem is I cannot crawl into the trunk as the levers to get the back seats down is in the trunk. Catch22. I will try recharging the battery from the underhood terminals.

[F87source]

Originally Posted by zazzi

The problem is I cannot crawl into the trunk as the levers to get the back seats down is in the trunk. Catch22. I will try recharging the battery from the underhood terminals.

That's the only place the battery should be recharged while still connected to the car.

[///M TOWN]

Originally Posted by zazzi

The problem is I cannot crawl into the trunk as the levers to get the back seats down is in the trunk. Catch22. I will try recharging the battery from the underhood terminals.

You should be able to pop the trunk if you've got power connected to it

Ignition on of course

[zazzi]

Originally Posted by zazzi

Hello Folks,

We are doing some body repairs on a 2021 M2. The car has been sitting here for about 4 months now (waiting for some back ordered parts from BMW). The battery went dead and now we cannot start it. Jump doesn't work either - no power in the dash when we put the jumper on. Can't open the trunk to look in to the battery/fuses due to lack of power on the car. Can't hook on the scanner either.

Anybody faced similar issues? Any help would be appreciated.

Thanks.

Thanks to all who responded.

I tried hooking a CTEK tender but it does not detect the battery - so possibly the battery is dead. Now the question is lets say the battery is completely dead, can't I still put the jumper under the hood and power on the car to a point at least to open the trunk? Is there a main fuse that has blown? If so, where is the main fuse located.

[zkeeper]

Ok will jump in here...probably get flamed. But a similar situ as I store the car and always disconnect battery...but made mistake of closing trunk with it disconnected.
No way to crawl through back seat...you have correct...so went to Autozone, bought the NOCO Boost Plus little gadget, paid enough for it, but at that point I could care less.

Charged it good and long, popped the bonnet, as it needs no battery, (as door was open) attached NOCO properly, and in a moment, I could push the trunk button as there was enough volts??? (hey I am not into what it took to do that) and voila, open boot lid.

I always have a nice towel at trunk lid opening so as to leave it safely open, but, well that time, was in a hurry and just shut the trunk out of habit.

You still will need to replace the battery---for peace of mind. Fuses?? I know nothing but I DO know how to get the thing open and started now with my NOCO. Hopefully this will help you.

[zkeeper]

BTW-- the CTEK was a circuit issue and yes, no detect of battery. The NOCO was an outside source for enough to activate the trunk button. Bests on this...most irritating at best to deal with it.

[zazzi]

Originally Posted by zazzi

Thanks to all who responded.

I tried hooking a CTEK tender but it does not detect the battery - so possibly the battery is dead. Now the question is lets say the battery is completely dead, can't I still put the jumper under the hood and power on the car to a point at least to open the trunk? Is there a main fuse that has blown? If so, where is the main fuse located.

Still no luck. Tried all possible solutions I can think of. Haven't given up yet. Still trying....

[DanG]

Originally Posted by zazzi

Still no luck. Tried all possible solutions I can think of. Haven't given up yet. Still trying....

Since you are under warranty, why not call BMW Roadside Assistance and have them fix your problem? You can call them direct from the MyBMW app or at 800 332-4269.