I did a big thread (all info in first post) on swapping out the mid sized battery for a bigger case size...all info on case sizes & VCDS coding etc in this thread here:-
How to retro-fit a bigger capacity battery to a Mk7 Golf | GOLFMK7 - VW GTI MKVII Forum / VW Golf R Forum / VW Golf MKVII Forum
Quotes:-
If the car has "stop/start" auto engine shutoff & restart (not to be confused with KESSY which is keyless entry & start).....you need at least an EFB type & pefferably an AGM type.
This is what VAG fit at the factory:-
For cars WITH "Start/Stop” eco engine shut off (BlueMotion II):-
59Ah/320A (DIN), H5 size, EFB type
69Ah/360A (DIN), H6 size, EFB type
68Ah/380A (DIN), H6 size, AGM type
H5 is the mid sized case, H6 is the biggest case size.
Varta who make some of the batteries for VAG confirmed that standard battery case sizes are used to make the VW factory batteries, but that the Ah capacities are “special” to VW for those case sizes. Basically, VW are confusing us to make sure we end up buying a direct replacement battery from them when in fact a standard battery which is available from any auto parts supplier will fit & do the job!!
So long as the case size is the same or bigger than your factory battery & the Ah/CCA is better then buy what every you can from any car parts supplier...
VCDS coding required
From the Main screen:-
Select Control Module [Select]
[19-CAN Gateway]
Advanced Functions screen:-
[Adaptions-10]
New value choice screen:-
Change the following four channels, inputting the relevant data about the new battery.
IDE03256-MAS06105-Battery adaptation-Rated battery capacity
IDE03256-MAS06106-Battery adaptation-Battery technology
IDE03256-MAS06107-Battery adaptation-Battery manufacturer
IDE03256-MAS06108-Battery adaptation-Battery Serial Number
When you click on "Battery technology" (using VCDS 21.3.0) a drop down list appears with the following options (= actual meaning):-
Wet = Standard Lead Acid
Fleece = Standard A.G.M.
Wickel6V
Wickel12V
Ultracap
Gel = Standard Gel Lead Acid
Lithium ions = Standard LiFePO4
EFB = Standard E.F.B.
Binary - AGM = "Bipolar" A.G.M. type
EFB+ = E.F.B. "Plus" type
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Unknown
According to various sources of information, including numerous car scans & threads on Ross-Tech, "Fleece" is for standard AGM batteries, "EFB" is for standard EFB batteries, & "Wet" is for standard lead acid batteries, as these settings are used at the factory. The setting of "Binary - AGM" is apparently for specialist "Bipolar AGM" batteries! Also the drop down list is from VCDS & not generated by your car's BCM, therefore, your car may not support all the options on the list, & the BCM will reject the value when you tell it to accept it!
Battery BEM codes are now redundant with the above separate channels. The most important channels are:- Rated battery capacity, Battery technology, & Battery Serial Number. For the Battery Serial Number, just change one digit of the old one. This channel tells the BCM that a new battery has been installed & to relearn the new battery & forget any “learnt values” for the old battery!