[liftrichh]

I just changed my battery, ibs sensor and alternator recently. I bought the ibs sensor and alternator from fcpeuro. My friend coded my battery via protool but i am still getting a voltage light popping up. Any tips??

[cranelec]

Originally Posted by liftrichh

I am still getting a voltage light popping up. Any tips??

Non-Specific BMW battery/charging systems checks.

I think a digital VOM is your best friend. Background info:A fully charged new 12 VDC battery should read 12.7 VDC.

WithOUT your car running, place your meter leads across the battery terminals. If you read anything below 11.4 VDC, your battery is smoked (dead cell).

With your car running, place your meter leads across the positive & negative terminals...if you read >13.8 VDC (Battery? Alternator ok), ...if you read > than 14.0 VDC (Battery & Alternator ok).

[Pladi]

Originally Posted by liftrichh

I just changed my battery, ibs sensor and alternator recently. I bought the ibs sensor and alternator from fcpeuro. My friend coded my battery via protool but i am still getting a voltage light popping up. Any tips??

We need more information.

Such as is the light on ALL the time or during pulls ONLY.

Also you need to do your own testing. You cannot assume anything. What is the voltage at the battery when the car is running. What is the voltage of the battery during cranking. These tests can help you find out if some other component is pulling the voltage down. ( Extra load)

Replacing parts blindly is not a good approach.

[cranelec]

Originally Posted by Pladi

We need more information.

Such as is the light on ALL the time or during pulls ONLY.

Also you need to do your own testing. You cannot assume anything. What is the voltage at the battery when the car is running. What is the voltage of the battery during cranking. These tests can help you find out if some other component is pulling the voltage down. ( Extra load)

Replacing parts blindly is not a good approach.

Pladi is correct! Your current circumstance cries out for more info. FYI: A brand new lead-acid battery properly manufactured, electro-chemically formed (charged)...should read an open circuit voltage (OCV) 12.9 - 13.4 VDC. Approximately one hour later, that new battery's OCV should read 12.8 VDC +/- 0.02 VDC. (I worked at an OEM lead-acid manufacturing plant for nine years).

Upon noticing the voltage CEL, the first thing I would do is place your meter leads across the battery or under hood terminals while the car is idling. If your VDC reading are > 14.2 VDC, your alternator is.

Unlike the average car, BMW allows your battery to discharge deeper (i.e. lower than other automotive manufacturers normally permit before the voltage regulator "kicks" in).


The initial and least costly course of action you should undertake is leveraging national automotive parts suppliers(e.g. Advanced Auto, Auto-zone, etc.) willingness to have there "over-the-counter" sales associates preform a battery "breakdown" test for free.

The best "rule-of-thumb" I can suggest is that a fully charged battery should read 2.2 VDC per cell or an open circuit voltage reading of12.8 VDC. (absolutely no load or parasitic draw present).