Question on Battery Replacement and Battery Tender Installation

I have a mini 1.6 cooper 57 R56 model, The battery keeps draining, I have checked the alternator and is putting out 13.5v, when I take the battery off the car it was putting out 11.4v on the car it went down to 4.4v. I have a had a "Black Box" fitted for my daughter, could this be draining the battery?

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This post was auto-generated based upon a question asked on our tech article page here: MINI Cooper Battery Replacement and Battery Tender Installation (R50/R52/R53 2001-2006) | Pelican Parts DIY Maintenance Article

[Nick at Pelican Parts]

Do not remove the battery cables with the engine running, that will damage the alternator.

Possible the item is causing a draw. You'll want to monitor the draw on the battery when the vehicle is asleep. Here is a list of the specifications: http://autotechdiagnostics.com/?p=185
Once you confirm there is a draw. You will have to isolate the circuit with the draw. Then determine which components on that circuit is causing the draw You can isolate by removing fuses. be sure to have all the latches on the doors and hood closed (pin switches) so the vehicle will sleep during testing. If it wakes up, you will have to wait until it goes to sleep again.


- Nick