E65 2003 battery voltage

[oliverd642]

Hi all!

I recently purchased a 2003 bmw 745i with what seemed to be a bad battery giving me a check engine light, I charged the battery and the engine light went away. A few days later, the car started (only just) and give me a check engine light again. Yesterday I purchased a new battery and the light went away again. Now here's where I'm confused, the new battery reads 12.63volts but when it's connected to the car it reads only 12.22 volts? Is this normal on the e65 because I've never seen this before or at least I don't think I have.

After replacing the battery it also seemed to trigger my airbag light.. I have a c110 obd reader but it does not work on my e65?? The screen is just white and nothing happens. The scanner works on my 99 e39 540i and also worked on my friends 2008 bmw x3 so does anyone know anything about this?

Thanks!

[oliverd642]

Anyone??

[MrBurger]

Did you register the battery? If you don't, the Power Module will not reset its charging map and you'll end up with another bad battery soon..

Whenever you add a load to a battery (ie, connect it to a car) the voltage will drop a little.

Mr_B

[mandd]

A bad battery will not give you a Check Engine Light. Find someone with the correct equipment to scan your car (DME).

Mark.

Hi all!

I recently purchased a 2003 bmw 745i with what seemed to be a bad battery giving me a check engine light, I charged the battery and the engine light went away. A few days later, the car started (only just) and give me a check engine light again. Yesterday I purchased a new battery and the light went away again. Now here's where I'm confused, the new battery reads 12.63volts but when it's connected to the car it reads only 12.22 volts? Is this normal on the e65 because I've never seen this before or at least I don't think I have.

After replacing the battery it also seemed to trigger my airbag light.. I have a c110 obd reader but it does not work on my e65?? The screen is just white and nothing happens. The scanner works on my 99 e39 540i and also worked on my friends 2008 bmw x3 so does anyone know anything about this?

Thanks!

[White94RX]

A bad battery will not give you a Check Engine Light. Find someone with the correct equipment to scan your car (DME).

I was going to post the same thing, but you beat me to it.