[injb]

Sure. Trickle chargers usually never shut off. These are AGM batteries, not the older lead acid batteries. They want to be charged at 14.7V, not 14.4V. You can start by reading this massive thread

Charging the Macan

Caveat: The following is information only. Caveat Emptor. These products are not Porsche official products and your use is on you. What has worked for me, and the risks I take, might not work for you. The following is, in good faith, correct to my knowledge. If anything is wrong, say so and lets...

www.macanforum.com

and watching this video

smart chargers will go to some kind of pulse mode only sending a boost when needed.

Further, AGM batteries ALWAYS want to be fully charged. Read your warranty, regardless if the car is out of warranty. They warn you. Not driving, plug it in.



And that is exactly why this thread exists. I'm guessing today, with inflation, its close to $1000 to get a new battery from a dealer and have them register. You can read the arguments in this and other threads. The arguements have gone on since 2012, when the first AGM went into a Porsche. AGM did come with start/stop. I would ignore the cynics. Want an answer, ask Porsche AG, not your dealer, but the car maker. Let us know what they say

OK I was confused because you referred to the newer CTEK charger as a trickle charger earlier in the thread, saying that trickle chargers were needed:

AGM charges at 14.7 volts, not 14.4, hence the need for trickle chargers, like the newer CTEKs, with snowflake mode which is for cold weather or AGM batteries (14.7 volts).

In any case my charger uses a microcontroller to detect when the battery is fully charged, and then it stops.

I read about the whole registration thing on Varta's website here and this is what they have to say

Others diagnostic tools like Hella Gutmann or BOSCH KTS create the required battery specific information using drop-down options. Entering the BEM code is not required. You just need to select the capacity, manufacturer and technology. The serial number requested is just for traceability purpose. Any 10 digit number can be applied.

Granted that example was for VAG cars but the BEM codes are obviously identical to ours and contain the same information.

 

[injb]

Well I just installed the Interstate H8 95aH battery. But first I was curious to see if I could reactivate my start/stop feature by registering the existing battery as a new one. So I used the iCarsoft POR 2.0 to register it. Like this person I had to use the 911 option because the Macan option didn't work.

It didn't make any difference to the start/stop feature. It was still deactivated. So I installed the new battery, and immediately the start/stop feature started to work again, without registering the new battery. So that proves that this feature gets disabled not only based on the info that the car has stored about the battery (if it even uses that at all), but also based on what it can detect about the battery's condition.

The next question was, what if I had replaced the battery but didn't register it - would that have reactivated the stop/start feature? I hoped to answer that question by registering the new battery as the old one. But unfortunately this wasn't conclusive because I don't have any way of knowing what numbers Porsche used to register it at the factory. The iCarsoft wanted a 15 digit "scanner number" and an 11 digit "part number". The only 15 digit number on the battery was the QR code number (which Varta says shouldn't be used). There's no 11 digit number on the battery - the Varta part number is 10 digits. The Porsche part number is apparently 95861109221 which is 11 digits. This doesn't appear on the battery, which isn't surprising because the battery is stamped as "VW". So I tried registering my new battery using the QR code and the Porsche part #, but the start/stop remained active after that.

So either (a) the car didn't recognize it as the old battery because those weren't the numbers used at the factory, or (b) the car did recognize it as the old battery but it doesn't care about that for the start/stop feature.

Charging voltage was, as always, all over the place regardless of whether I registered the new battery as the old one or with new numbers. So I think the charging is based mostly (if not entirely) on what the car can detect from the battery, along with many other variables (temp, load etc.).

My guess is that anything the car does with the stored info about the battery is subtle and not hugely important. But there's no way to know for sure.

 

[embdenb]

There is a theory that registering the battery has nothing to do which how the car charges the battery. Registration is designed to track battery models / amperage etc. and how often the battery is changed.

 

[injb]

After a few days of driving, I can say for 100% certain that there's a big difference in the voltage shown on the MFD. With the old battery it tended to stabilize around 14.5 or so. With the new battery, it's around 13.1. As I said before, there's no way to know to what extent this is due to it being registered, vs. just being a new battery.

 

[embdenb]

I am not totally convinced that battery registration has anything to do with the rate the battery is charged. AFAIK The majority of cars do not require battery registration and they charge replacement batteries just fine. Even the cheapest battery maintainer will charge a battery based on that batteries feedback as to its charge state.

 

[injb]

I am not totally convinced that battery registration has anything to do with the rate the battery is charged. AFAIK The majority of cars do not require battery registration and they charge replacement batteries just fine. Even the cheapest battery maintainer will charge a battery based on that batteries feedback as to its charge state.

You may be right. Although battery maintainers and trickle chargers probably charge with constant current, unlike the car's charging system. Most cars charge with constant voltage afaik. But it's possible that the registration has nothing, or very little to do with it.

 

[grim]

You may be right. Although battery maintainers and trickle chargers probably charge with constant current, unlike the car's charging system.

Not CTEKs. Read the manual. During the absorption stage the voltage stays at 14.7V while the current declines.

 

[Jbunceiii]

Can anyone confirm that the iCarsoft 2.0 with firmware 11.50 fixes the battery registration issue with having to pick 911 instead of the Macan?

 

[injb]

Can anyone confirm that the iCarsoft 2.0 with firmware 11.50 fixes the battery registration issue with having to pick 911 instead of the Macan?

It doesn't - read the post I linked to above.