Old topic but still not sure. If I replace the battery on my f25, using the same size and type, and maintain system voltage by connecting another battery during the change, does the new battery need registering or anything else? That just worked OK on my wife's e39, but that is older technology, and some years ago worked OK on my e61. BTW excellent service and price from Tanya Batteries for the e39 battery. Ordered in afternoon, battery arrived early next afternoon.
A new battery does NOT need any registration provided it has the exact same specifications I did just that last month without drama.
This just so wrong. As a battery ages the car adjusts its charging to suit, ie the charging pattern for an old battery is quite different to a new one. You won't have immediate problems, it's the battery's longevity that will be affected..
Coding the battery type (Lead Acid or AGM) and capacity (Ah) - does affect the charging patterns. So a change like for like does not need coding. Registration advises the car a new battery has been fitted and it needs to discard its history regarding the state of charge of the battery. If you don't register the new battery the car will still believe it has a worn and flat battery fitted. You may still get warnings about low battery until the car figures it out (could take 30 days). If you don't register and you just fit a fully charged battery, after fully charging the old battery on the car, then you might get away with it. It won't be ideal but in practical terms it will probably be fine. Charging lead-acid batteries and AGM batteries isn't very complex - you supply them with a voltage (say 14.3V) and the battery itself regulates the current it needs. As long as you don't supply too high a voltage you won't overcharge the battery. You can leave a lead acid on charge at 13.8V indefinitely. Think about smart chargers - they don't need to be told the state of the battery - they sometimes need to know AGM or Lead Acid. A smart charger, and the IBS (Intelligent Battery Sensor) can successfully charge the battery under most conditions. The problem here when you fit a like for like battery is registration and the state of charge of the battery. When the swap occurs the car has logged that the battery is at say 20%. Without registration it doesn't know the battery is now 100%. That means the car will continue to give low battery warnings and continue to restrict use of heated seats, rear demist, high fan speed etc. It will confuse the IBS when the battery that it thinks is at 20% doesn't charge (because it's really a battery that's 100% full). Eventually the IBS will sort of figure it out - but it's not ideal.
With all respect, you can of course register your new battery, suit yourself. But in de F25 ( and E60 etc.) the IBS does just that for you. It is a self learning system, and it works just so with your weakening old battery. And, again, it will resume its values for the new battery. This may take quite a few miles, but it works. From a German website ( just to say that I did not invent this myself ): "Also von einer gebrauchten Batterie würde ich definitiv Abstand nehmen, wer weiß, was die alles schon erlebt hat. Original muss es nicht sein, würde jedoch eine Markenbatterie vorziehen. Ein Chinaböller muss es auch nicht sein. Außerdem wäre es immer einfacher, wenn du denselben Batterietyp nimmst, mit den gleichen Daten. In dem Fall muss die Batterie wohl auch nicht unbedingt angelernt werden (ist aber eher eine Glaubensfrage)." ( Don't substitute with a second hand battery. When you install a new battery with the same characteristics you don't have to "learn it in" ). Have a nice weekend.
I go to a m8's garage on a Saturday morning for a catch up now i am out of the job. He had a car in some weeks ago can't remember the make but when he fitted a new battery it asked him on the dash when he turned the key if a new battery had been fitted and you chose yes or no.
