Hi,

 

has anyone tried to replace their car battery themselves? Maybe changed EFB+ to AGM? Do you need to provide the car with power supply while doing it?

 

Cheers

Hello, welcome to the forum. 

New battery will require adaption (coding) to the vehicle, especially if type or capacity is different to original - this battery adaption is done via VCDS (or similar device) plugged into the OBD port.

  It is not necessary to maintain the 12 volt supply during a battery disconnection, the DTC faults generated when the new battery is connected will clear after a short drive. 

Soluiton:

 

I guess you missed what Warrior193 posted back to you 15mins after your question. It is pretty much what you have posted back.

 

I.e.

1. Buy a battery

2. You don't have to maintain power during the swap

3. Code it with VCDS or equivalent.

Of course I did not miss his post but I was more curious about how to do it with VCDS since it has a SFD lock. Maybe it would even be possible to do with VCDS but I did not know I need to manually clear the errors before setting up a new battery in the computer. Also, for me personally there is a big difference if 1 person says I don't need to keep power or if 5 people say that. Would make me more confident.

40 minutes ago, octaviaIV_lover said:

Of course I did not miss his post but I was more curious about how to do it with VCDS since it has a SFD lock. Maybe it would even be possible to do with VCDS 

Ross-Tech are negotiating with VAG to add SFD unlock into VCDS, they've jumped through all the hoops and paid VAG a princely sum so now it's down to VAG's glacially slow procedures to make it happen.

 

You don't need to keep power applied when changing the 12V battery on an ICE version (can't comment on iV versions), the errors that will appear when the new battery is applied will clear after a short drive. If the thought of errors appearing upsets you then by all means use one the easily available backup leads.