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Old 01-25-2013, 06:03 AM
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Fish23 Fish23 is offline
Officially Welcomed to the 'Fest
Location: Ottawa, Ontario, Canada
 
Join Date: Apr 2012
Posts: 521
Mein Auto: BMW 535xi GT
Noodles23, good choice for a two-digit number in your forum ID.

Thanks for that input. I am glad I am not alone and once again this forum helps me understand my GT better especially in terms of cold weather performance. My weakened battery, frigid temperatures (that reduce any battery's capability) and a regenerative braking system (RBS) that is not designed to work until the car is 'warmed up' (according to my SA) makes for the problems I experienced after a 15-minute trip. I also learned that the electric alternator will only charge the battery at highway speeds with full charging taking place at 3000 RPM! My GT is doing 75 MPH at 1900 RPM so to charge a depleted battery would take a long trip.

For the duration of this cold snap I am using use an inexpensive solar charger during the day and with a plug-in charger on Trickle while at home overnight to keep my new battery in peak operating condition. This is also recommended for any longer periods in any weather where the car is parked in a " fully-shut down" condition since there are enough functions operating in a quiescent state to deplete the battery.

For what it is worth, here in Ottawa, Ontario my dealer saw so many situations of battery problems (not related to the actual battery itself) that telling clients to drive more no longer cut it. Now, since 2012, the dealer is pro-actively installing a trickle charger in the trunk of every new Beemer it sells and puts a $200 cost on the sticker and recommend it to people like me. I preferred an actual charger I bought myself that sits nicely in the space at the left front of the engine bay of the 535 and run the cord out to an extension cord to the house. That way I can use one of the 6 amp Fast, 4 amp Medium or 2 Amp Trickle charges. The charger goes to Trickle automatically when the battery is "full".

None of the above was explained to me and I learned the hard way so I have recounted it for the benefit of our F07 group and and any other Beemer owner with the RBS.

Last edited by Fish23; 01-25-2013 at 06:24 AM.
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