Quote:
Originally posted by RickDaTuner
Not to call anyone out, but BMW places the battery in the rear right wheel well area for Weight distribution.
A charged battery can also go to -70c, and only to -10c completely discharged before it fully freezes.
BMW batteries don't last very long due to the nature of the BMW control modules power consumption.
A car sitting with the key in and engine off, can draw as much as 40 amps, this in turn causes harsh charge and discharge cycles which leads to plate sulphation, and dramatically reduces its life.
For comparison most cars draw about 30-35 amps while running, in those instances the alternator takes care of the electrical load, and allows the battery to act a buffer.
BMW modules all act like mini computers, they all have their own processor, and programmed lines of logic. Each module may draw up to 2 amps of power, but being that some BMW cars have over 100 individual modules, the power consumption really adds up.
Almost all other automobiles modules work off an eprrom logic chip, which uses far less power.
One of things you can do to increase battery life in a Beemer is to buy the biggest battery available for the car, and also make sure its an AGM.
Some cars are starting to come with NiFe Batteries, but require its own charge control, and are pretty expensive.
Ford was also shipping out Li-ion batteries on some of the transits as well, but because of shipping regulations, you can't buy them form the dealer.
It was mentioned, but it is a really good idea to use a trickle charger overnight, and especially if you don't plan to use you vehicle for a few days.
Not making a case for modern BMWs here. Given the advancements that competitors have made in the markeplace on BMW in recent years (ATS-V vs M cars, for instance), a lot of this stuff is inexcusable.