Let's start this post with providing some context.
A couple of month's ago I purchased a 2015 (Series 2) Skoda Superb 'Tour de France' Estate 2.0L Diesel 4X4.
It had covered 170k miles, had a full service history and was in good condition. It was not perfect and needed a few, relatively inexpensive parts to bring it up to scratch.
I am reasonably handy with the spanners and have VCDS and Autel (Pro level) diagnostics equipment.
One of the issues was a battery that was clearly on the way out. It was the original VAG badged 68 amp AGM Varta battery but it had done extremely well to last this long!
I purchased a replacement 70amp AGM Varta Battery from Tayna Batteries.
Now for the adaption on Channel 4. Having fitted the battery, I used VCDS to enter the new battery's adaption values. The original battery was recorded as 068 JCB 1111111111
18 digits including the spaces (1 space = 1 digit) are required.
The code for Varta is VA0 (that's zero not capital 'O').
There are plenty of posts / You Tube videos that suggest you enter 'O' not '0' (zero) after VA for a Varta battery.
They also suggest that you end the sequence of 1's with a 2. This is what I did, the new adaption values were accepted and I assumed that everything was ok.
The big problem here is that whatever you enter, providing you use the correct format, will be accepted, lulling you into a false sense of security that what you have input has been accepted and has adapted your new battery!
If you have an AGM battery or equivalent, needed for the start / stop function, the adaption code (the series of 1's after the space, after JCB or VA0 is in binary. Entering the number '2' will be accepted but it is not a binary number and will not result in your new AGM battery being adapted.
SO WHAT!
Not a problem if your new battery does not become drained. You will not notice any issues and will probably be none the wiser!
The problem is that your battery generator function will not be operating as you have not adapted your new battery correctly. If your new battery becomes drained below say 11v, your battery warning light will come on but before the battery warning light comes and the voltage had dropped to just above this level, some of your functions may start playing up. Examples of this may include power steering working intermittently and heater blower fans not functioning. The battery generator function works like a relay and allows the battery to charge to its optimum level. If the battery generator is not functioning, due to the battery not being adapted properly, it will never charge beyond its current value, whatever that may be.
In my case I installed an aftermarket head unit, amplifier and component speakers. Testing the system (with the engine off), but the ignition on, must have depleted the battery. This morning, the car was iced up. I started it with heater blower on full and rear window heater on. The battery warning light came on and did not go out, despite a 45 mile journey down the M1. Luckily for me, I had my Autel Pro diagnostics scanner on me so I interrogated the live data. This showed that the battery was not charging above 10.7V.
I went into the battery's function adaption screen, cleared the value I had input originally, when I installed the new Varta 70amp battery and input the following:
070 VA0 1111111111
This, when saved, resulted in the battery warning light going off and staying off. The battery also started charging up to its optimal level.
Sorry for such a long, rambling post but I hope this can be of help to others.