2006 E91 330d - red battery symbol on display

[Martyn76]

Hi All,

Had the red battery symbol appear on my dash this morning during the school run, car was running normally, after getting back into the car after dropping the kids off I restarted the car and hey presto no battery symbol!

Is it a sign my battery is on the way out, car is 11 years old and still on the it's original battery as far as I know.

[Collectingbrass]

Could be. Have a look at the sight glass on the top of the battery. If the battery is over 5 years old (it should have a manufacture date on it somewhere on the top) I would change it out. Even then I would look at the system voltage. There's 3 points you should be looking at the voltage; cold & everything off inc NAV / idrive asleep, cranking / starting and engine running (& charging) under load. This thread has the details but you should be seeing around 12.5v, 9.6v and 14v on a healthy system

http://www.bimmerfest.com/forums/showthread.php?t=...

I would get a cheap OBD bluetooth reader (https://www.amazon.co.uk/d/ijq/Torque-Pro-Elm-327-Android-OBD-Bluetooth/B01AC7I7BO/ref=sr_1_1?ie=UTF8&qid=1502519491&sr=8-1&keywords=odb2+bluetooth) and the Torque app & see what the ECU thinks the voltage is. You will also be able to see whether there are any basic error codes - but it wont give you everything

[Martyn76]

Thanks for the reply, I've actually got a BT ODB dongle at home (still in it's packaging) and the Carly app, will connect it up and see what I can find out.

[Smuler]

Martyn76 said:

Hi All,

Had the red battery symbol appear on my dash this morning during the school run, car was running normally, after getting back into the car after dropping the kids off I restarted the car and hey presto no battery symbol!

Is it a sign my battery is on the way out, car is 11 years old and still on the it's original battery as far as I know.

I would say it could be, red is bad from my E92 experience.
any error codes, any warning stored in iDrive if you have that?
but when my M3 battery went, I had problems, no radio, before and the death was more immediate, so maybe something else is amiss.
Isn't there a way of checking if battery is charging correctly, I can only recall on E46 how to do that. worth googling.
On my M3, it was the original, lasted 12.5 years; there was a date that's how I knew.

[dave_s13]

On my 57plate e61 I'm sure you could see the battery voltage in the hidden menu on the dash....will this have a similar thing?

It's about the right age for a battery to start going I reckon.

[Collectingbrass]

Martyn76 said:

Thanks for the reply, I've actually got a BT ODB dongle at home (still in it's packaging) and the Carly app, will connect it up and see what I can find out.

I don't think the Carly App will work with any other dongle, but the Torque App will and the free version will give you voltages in the display

[SebringMan]

IMO when it next does it see what the voltage is at the battery terminals with a multimeter. I'd then go and do some diagnostic work. If you are in Warwickshire I'm happy to scan the car using INPA, a known BMW diagnostic software package.

[Badgerboy]

What will happen next is the car will start shutting down systems to save power to crank the car. The most common sign will be the clock resetting.

Remember the alternator is not charging the car continuously, so short runs do not get a decent charge in the battery. (Alternator usually kicks in on deaccelleration, better MPG that way)

You can always charge it up, but if it's 11 years old it's likely on its last legs. Remember to change it like for like, especially if it's a AGM battery.

Replacement will also need coding. (Car needs to know it's a fresh battery so the IBM will charge the battery with the optimum charging profile)