[Charles Martin]

Bought a 325 just over a year ago. The dealer replaced the battery but suspect it wasn’t registered. Now getting a message saying increased battery discharge. Am I too late to register the battery or can I still do it. Alternator charging and battery has tested fine incl a load test. Did notice alternator is charging between 14.8 and 15.2 which I feel is a bit high. Compensating for the old battery?

[lookalikehuuh]

Battery registration won't cause an "increased battery draw" warning. Usually that occurs because something in the car isn't turning off and drawing more current than the car expects.

Many times this is caused by aftermarket items like dash cams, android head unit, aftermarket amplifiers etc. At time it can be a failing intelligent battery sensor, a bad diode in the alternator, a stuck water pump, etc. What makes you think the dealer never registered the battery? Using a good scan tool you can actually tell when the last time the battery registration occurred.

Your increased alternator voltage could also be a result of the constant battery drain, since the battery is going to end up in a weaker state due to the constant draw the alternator will need to work harder to get the battery back up to proper charge. It is also much more common to have alternator voltage be higher on startup and taper off and the engine has run longer since the battery charge will improve after a few mins of charging occurring. So when you measure the voltage is important. Once the car has been running for a little while 10-20mins then try measuring the charging voltage as that should give you a better idea of the true system voltage.

[Charles Martin]

Originally Posted by lookalikehuuh

Battery registration won't cause an "increased battery draw" warning. Usually that occurs because something in the car isn't turning off and drawing more current than the car expects.

Many times this is caused by aftermarket items like dash cams, android head unit, aftermarket amplifiers etc. At time it can be a failing intelligent battery sensor, a bad diode in the alternator, a stuck water pump, etc. What makes you think the dealer never registered the battery? Using a good scan tool you can actually tell when the last time the battery registration occurred.

Your increased alternator voltage could also be a result of the constant battery drain, since the battery is going to end up in a weaker state due to the constant draw the alternator will need to work harder to get the battery back up to proper charge. It is also much more common to have alternator voltage be higher on startup and taper off and the engine has run longer since the battery charge will improve after a few mins of charging occurring. So when you measure the voltage is important. Once the car has been running for a little while 10-20mins then try measuring the charging voltage as that should give you a better idea of the true system voltage.

Thanks for the reply. Reason I think it wasn’t registered is that the battery was bought over the counter and the dealer isn’t a regular BMW seller. Will take your advice on the other items you pointed out. For example the charge rate was checked shortly after startup. Thank you. Also, the discharge warning only comes on when the car is switched off but in aux mode or if it’s been standing for a few days.

[lordnikon]

Do a diode check on your alternator as well.

[lookalikehuuh]

Originally Posted by Charles Martin

Thanks for the reply. Reason I think it wasn’t registered is that the battery was bought over the counter and the dealer isn’t a regular BMW seller. Will take your advice on the other items you pointed out. For example the charge rate was checked shortly after startup. Thank you. Also, the discharge warning only comes on when the car is switched off but in aux mode or if it’s been standing for a few days.

Wait wait wait... this makes it even more confusing, how is it a dealer but not a BMW dealer, then you mention you bought the battery over the counter... Talk about multiple stores woven into a single sentence.