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      11-03-2017, 12:43 PM   #5
Surly73
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Drives: '11 535xi 8AT KWv3 MPE MHD xHP
Join Date: May 2012
Location: Oakville, Ontario

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Quote:
Originally Posted by mfshin View Post
I have the same problem.
I believe battery is charging ok, it's just that when coasting that blue light does not come on (never) and it's been going on for months.
Amyone know how I can get this blue light come on again?
My recommendation - don't obsess about the light. Although it's odd that it doesn't come on, it's all just software. Measure the system voltage. Just because a little blue bar designed by Marketing doesn't light doesn't mean your battery isn't being charged.

Assuming you have an AGM type battery (which all of us with F10s seem to) then it should measure 14.8VDC when it is charging at max rate. You should see this at some point when the car is running. This is a system voltage which will recharge the battery as quickly as it is able.

A voltage suitable for "float charge" when the battery is near fully charged is more like 14VDC.
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