Hi guys,

I've been reading the high battery drain threads and there seems to be open questions about:

- whether or not this is a control module issue, or a battery issue
- does the battery, if replaced requires "reprogramming" from BMW (charge data dump etc).

I've been having this error for the last few days, usually only in the morning. Once I start and drive around, park and restart generally the error is gone and it won't return until the next morning. I've had no resets of clock or any other electronics, the car goes into sleep mode, iPod turns off, everything appears as normal. (the only other issue I'm having is that the keyfobs are not working on the car).

I put the car on a trickle charger yesterday/last night, before I started it this morning the charger showed that the battery was completely charged. I disconnected and started the car and the High battery drain indicator came on again. I put the charger back on the terminals and it showed only a 50% charge on the battery.

So, given that my car appears to sleep fine and still has high battery drain while on a charger am I safe to assume that I need a new battery? If so, what's the definitive word on reprogramming? I'd rather just replace it myself but not at the expense of any electronic failures.

thanks,
Brad.

 

Not sure what type of "trickle charger" you are using. When I use my big charger on its trickle setting my car does not recognize it and the battery takes no charge whatsoever. If i set the charger on medium or high settings it charges the battery. I purchased a BMW battery tender float charger to maintain the charge in the battery when I am away but that one will not really replenish the battery in a major way.

 

Thanks for the reply -

I got this one:

Motomaster Charger

The charger I have does: 2A slow charge, 4A and 6A fast charge

I had it sitting on the 2A setting last night and showed "fully charged" this morning. I noticed that the batterytender does 1.25A, would that make a difference?

thanks,
Brad.