Increased battery discharge

[Les Grossman]

Hello chaps. Sorry if this has already been discussed. I did a quick search but couldn't immediately find what I was looking for.

My 1M was registered in July 2011. For the first two years of its life it only covered a little over 3000 miles. It's now on 12000 miles but is still very rarely used. It's not a daily driver.

Just recently it has been complaining about 'increased battery discharge' when I fire it up. It goes away after a few decent runs, but returns again if left sitting for a week. Each time, the car turns over perfectly and starts immediately with no signs of lethargy. When I dig into the warning message through iDrive, there's some comments about electrical connections or some such (from memory).

My first question - is this likely to be a battery issue (given the car's age and only light use) or an actual electrical gremlin as the iDrive might suggest? I'm guessing the former is more likely, but I have extended comprehensive BMW warranty, so the latter should be covered.

My second question - I'm no spanner monkey but I could easily replace a battery. Although, given how compicated cars can be these days, and with their ever increasing reliance on complex systems, would battery replacement be something I'd be better off paying BMW to do?

Thanks.

[ThumpersM3]

Don't assume battery is bad ,have someone check codes and perform a Midtronics battery test to see if battery indeed bad.Any modern car with light usage should use a battery tender.I use one my 1M with 1,800 miles and never had a battery light on during the 3 years I had it.

For the second question, It is easy to change battery,but you'll need BMW diagnostic equipment to register battery to vehicle as being a replacement. Unless there's an aftermarket tool for this,not sure.

[Stratus650]

Its the battery, car is lightly used as well since 2012, had same symptoms, got battery replaced and never got the message again

[RS375]

If I don't use mine or a week or so I hook up a decent battery conditioner to the posts under the bonnet - a CTEK MXS5.0 in my case. I would give one of those a go first.

If you did change the battery it would need coding to the car.

[LeifW]

Originally Posted by Thumpers1M

Any modern car with light usage should use a battery tender.

This!

I have a battery tender on my 1M as well. I believe this saved my battery last winter, when the car was laid up in the garage because of the ice/snow on the roads.

Leif W.

[CarJunkie]

I just got this message last week. Car is 3 years old, about 25000 miles. I use the car regularly in the good weather months, but it sits for the winter. I have never used a battery tender; I just make sure to start the car and go for a long enough drive to heat everything up at least every 2 weeks in the winter. Our weather usually allows that. Maybe its time for a battery tender in my garage.

[de85275]

Try adding some water, I know it's "maintenance free" but not really, They are still lead-acid battery after all. I removed the cell plugs from mine, with difficulty, and added about a quart and a half of distilled water. (1.5L) The voltage before adding water was 12.4, after was 12.8 !

[Les Grossman]

Thanks guys. Seems most likely then that the battery just needs replacing.

I'll book it in with BMW after Christmas and also have my 2011 maps updated at the same time.

[smellthebeans]

Wow! that's a great tip! I guess "sealed" has relative interpretations. My car is now lightly used so I purchased a Ctek battery charger and hooked the pigtail eyelets directly to the battery.

[JimD]

If you are worried about your battery, test it. I have an inexpensive tester I bought from Harbor Freight. I don't know if that is an option in the UK but there should be some option. I paid about $20 for my tester. It is just a big resistor and a voltmeter. You push a button to engage the resistor and read the meter. It tells you the cold cranking amps. If they are too low, it's time for a replacement.

To code for a battery, the two ways I know you can do it yourself are NCSExpert and BMWhat. The latter seems easier to use and the former more powerful. It seems like you could pay for either with what the dealer wants for one battery coding. Maybe even save money. Both will do many other things. There are also people who code remotely and there may be one near you that could do it for you at a reasonable cost.

[eeghie]

Originally Posted by JimD

...

To code for a battery, the two ways I know you can do it yourself are NCSExpert and BMWhat. The latter seems easier to use and the former more powerful. It seems like you could pay for either with what the dealer wants for one battery coding. Maybe even save money. Both will do many other things. There are also people who code remotely and there may be one near you that could do it for you at a reasonable cost.

Hi JimD, (or others) do you have experience with the NCSexpert coding of a new/replacement OEM battery on a 1M? A short description or link would be appreciated.

[JimD]

Here's a good DIY - at least it looks good, I haven't had to use it yet.