Thread: Problem with X5
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Old 11-10-2012, 05:59 PM
PAX5 PAX5 is offline
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You say that the battery is new ... while it may be new, that does not mean that it is charged to the appropriate capacity to handle the complete load the car demands during startup.

Cranking power (CCA) of a battery is only one indication of the condition of a battery. That's why it can turn the starter motor. But, it also has to have sufficient reserve capacity to fire up all of the other electronics involved in starting the car. The reserve capacity of a battery is closely related to the Amp-Hour rating of your battery.

This is where things get interesting: if your battery is (recently) new and you or your dealer never registered and programmed the car's computer to recognize the new battery, then there is a good chance that you are either undercharging or overcharging the "new" battery. As your old battery ages, the intelligent battery monitor tells the alternator to put out more current. When you replace the old with new, the same amount of current will be pumped into the new battery. Either too much or too little is bad for the battery (over time). The end result is that you never charge the battery to its proper capacity and hence you end up with hard starting symptoms like you have now. The fact that you need to crank it 6 or 7 times is a good indicator that the battery is not at it's full capacity. Take the car back to the dealer and have them:
1. check the rating on your (new) battery
2. make sure the battery is properly registered
3. double check to make sure that the car is programmed for the proper Amp-Hour (Ah) rating of your battery.

BTW, doing this through the dealer can be very expensive!

Then, buy a Battery Tender and hook it up to the car on nights that it gets cold (40 deg or below) or if it is parked for more than 48 hrs.
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