wrong. Urban myth. Many folks on Rennlist, including myself, have changed their old batteries by themselves and all going strong. Your car has no idea what consumables are replaced. New tires, not Porsche approved, wrong brand of oil, not Porsche approved coolant, wrong brand of air in the tires. But go ahead and pay thru the nose if you want. I read it on the internet so it must be true!

 

No, that’s not true. I was talking with Atwong today ( he’s pretty much a self taught engineering guru as far as DIY Porsche stuff, the GTS/ Turbo spoiler swap, adaptive cruise control addition, etc, etc). Anyway he told me that the reason you need to tell the car the new info on the battery is two fold. One is that if the serial number and manufacture is not a Porsche serial number (or a VW number as they make a battery that is exactly the same as the Porsche battery) then the system will not reset the battery charge voltage that it set as the old battery aged. Therefore the new AGM battery will charge at a rate the old battery was charging at and this will decrease the lifespan of the new battery. I may have left a few things out of this explanation and if Anthony is monitoring this thread maybe he can elaborate but the crux of the matter is that there is a method to Porsche’s design and it benefits them as well as the owner to update the system when changing the battery.

 

You can believe what you wish.
I made my serial number up off the top of my head.
as long as it has the correct number of digits (see my link) it works. It’s not a Porsche branded battery. I changed it and coded it myself.
The module correctly changed the charging profile and all the stats stored within it.

 

I'm also confident that it does register in memory a battery change and saw a difference in the voltage display. Since the specs on the replacement battery I used were the same as the old/original Porsche brand battery I changed the last character of the serial number to another letter. I actually got this battery from Walmart. (Cheapest I could find). BMWs have a battery monitoring system that needs programming when a battery is replaced. My wife's ex '13 Ford C-MAX Energi also had a battery reset feature which I used ForScan to reset. Porsche could definitely implement this, and did....

I like to do things by the book. Torque spec for the terminal lugs is 6Nm.