hello,
i have a 2009 X6 35i and right now i am noticing the battery is having issues, mind you, for the
first time since i received my car back in Dec 2008... that is to say the battery has performed without incident for me through
5 winters.
this being my 6th winter, here are the symptoms i'm now seeing:
- saw battery drain warning sign on dashboard a few times
- need to reset time/date almost each time i enter my car
- car starts are becoming very hard - hear slow cranks before firing
batteries operate less efficiently in cold weather so i need to add that it is very cold here in Toronto. this winter is shaping up to be the one of the coldest in recent memory, today for example, is -25°C but with the wind chill it is -35°C. so this cold weather is no doubt making it harder for my battery to perform.
after reading many posts it seems i have an unusually long-lived battery. so my case may be the exception, and that my problems may simply be that it is finally time to replace my battery. but before doing so, i will be implementing the following tips starting today to see if they help:
- remove my iphone charging cable that is plugged in to my lighter socket
this past summer i bought a new iphone car charger and since have it plugged permanently to the cigarette lighter.. i read that it does trickle drain the battery even if it's not charging anything so over time this can't be good for the battery
- place my comfort access car key away from my car
that is, when i park my car in the garage at the end of each day. the reasoning here is that some say there is constant communication happening between the key and the car if they are in close proximity. not sure if this is true but sounds reasonable. trivial to do, so worth a try at least.
- take a long drive (at least once per week?):
even though it seems that everyone hates this advice since it's been the top excuse abused by the bmw dealer, i believe there is some truth to it since i used to drive about 46 miles round-trip for work each day, but for the past 3 years i am driving progressively less and less - now only 18 miles everyday and that is on city streets not on highway like before. the reasoning here is that your car battery does not get fully charged unless you drive long and hard. not sure if there is any truth to this, but some say that the alternator does not actually kick-in to charge the battery if the car has not warmed up to a certain temperature (to avoid putting undue stress on the engine and lessen emissions). others say it also helps to drive at higher speeds (i.e. long highway drives) of at least 90km/h (55mph). it is true, i don't drive nearly as long as i used to so this will be the best suggestion for me to try.
i might also try using a battery tender (BMW advanced battery charging system) since this charges the battery as well.
if i find my symptoms persist after all this, then it's time for me to finally replace my battery since it'll be evident that it can no longer hold any significant charge.
UPDATE:
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i just found this at Canadian Tire. it is the exact "Advanced Battery Charging System" that BMW sells (just rebranded):
http://www.canadiantire.ca/en/pdp/ba...-0111941p.html
i will be trickle charging my battery instead since driving long in this winter weather with snow and slippery conditions and in slow and messy traffic is not ideal.