Let's say my battery is three years old or older and I have to change it because it's bad. Does this mean my charging system won't work properly with out the dealer re setting the battery age? Great info by the way. Thanks!!!
The battery will still work properly as will he charging system just not optimally though as some of the data is skewed see here-
If the vehicle battery is replaced, carry out the Battery Monitoring System Reset using the scan tool. If the Battery Monitoring System Reset is not carried out, measurement data collected for the old battery is not deleted and future state of charge measurements will be inaccurate. For example, if an old battery has a state of charge of 60% and the new battery has a state of charge of 90%, the
BCM will recognize battery state of charge being 30% lower than it actually is. With the battery state of charge being perceived lower than it actually is causes shedding of loads earlier than is necessary. This also impacts the smart regenerative charge system by causing the battery to be maintained at a higher state of charge than perceived by the
BCM, reducing fuel economy benefits.