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Old 10-11-2012, 11:15 AM
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DSXMachina DSXMachina is offline
Bimmerdex 7.4!
Location: New Hampshire
Join Date: Dec 2007
Posts: 11,157
Mein Auto: 335i E92 TiAg 6MT ED
Originally Posted by Nordic_Kat View Post
Yes, your previous post in this thread had me ready for it, so I wasn't too surprised when they said it.

Yeah, I'm pretty much thinking the same way you guys are that the battery is on its way out. It's not like I've suddenly changed my drive style or cold/start behavior.
I will do the load test and see what that brings.

Your description is very good but pictures are always worth a thousand words. I may pester you for a photo once you get re-united with the E93.


I do have a question about alternators. When the SA was giving me the lecture about driving it more, he said something to the effect that "if you don't get the car up to 60-70 miles for a sustained amount of time the alternator won't spin fast enough or long enough to charge the battery." Does speed really make the alternator spin faster? Or is it just plain old time with the engine running that counts. If it's just time, then I could easily double my commute time by sitting in the gridlocked traffic on the freeway.
Holy Ageist Remark Batman! But here goes...How old is that guy?

He's thinking of generators! Once your engine gets over maybe a thousand rpm the alternator is putting out full rate. Some may take 2k rpm but that's rare.
The alternator is spinning all the time, though there is thought of putting a clutch on it so it presents no load when the battery is fully charged. However, it seems that in the real world the alternator has to contribute something all the time due to the high consumption of all the appliances in our cars now. Toaster oven? Microwave? Coming soon?
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