Can move to How to and tips!
Thought I'd do a quick write-up on replacing the battery in a S5 4.2 since I wasn't able to find all the correct info in one place.
1) Buy a replacement battery. Surprisingly, for me here in Canada, the dealer was cheaper than aftermarket. I paid $240 for an OEM (Varta) replacement. Part # 8K0915105F.
2) Replace Battery - this is pretty self evident and takes 10-15 minutes. The only setting I lost was the clock. Favorite radio stations, one touch windows etc., were all saved.
3) Code new battery with VCDS:
- Go to CAN Gateway 19, then Long Adaption, then Channel 4, Battery Identification.
- There are three strings of numbers in the following order (Part#, Battery Vendor, Serial #). For example:
8K0915105F VA0 080388159X
- I replaced the last 10 digits with the updated serial # on my new battery.
A few observations:
- Interestingly, the battery reading in the MMI was about 30% before and after I replaced the battery. It wasn't until I reset the battery serial # with the VCDS that it went up to 100%.
- My thoughts are that the battery reading in the MMI was never meant to give a reading based on current state voltage (…like a voltmeter would). But rather it is meant to give an indicator of overall battery life span given the monitoring of various readings over a long period of time.
- Resting voltage for my original battery was 12.1V. The new battery is 12.6V.
- Its pretty crappy given newer battery technology like AGM or VRLA (check these out if you aren't aware of them...), that we have to pay twice as much for an inferior replacement battery given the unique shape. I guess thats PAR for the course with these cars.
Cheers
Thought I'd do a quick write-up on replacing the battery in a S5 4.2 since I wasn't able to find all the correct info in one place.
1) Buy a replacement battery. Surprisingly, for me here in Canada, the dealer was cheaper than aftermarket. I paid $240 for an OEM (Varta) replacement. Part # 8K0915105F.
2) Replace Battery - this is pretty self evident and takes 10-15 minutes. The only setting I lost was the clock. Favorite radio stations, one touch windows etc., were all saved.
3) Code new battery with VCDS:
- Go to CAN Gateway 19, then Long Adaption, then Channel 4, Battery Identification.
- There are three strings of numbers in the following order (Part#, Battery Vendor, Serial #). For example:
8K0915105F VA0 080388159X
- I replaced the last 10 digits with the updated serial # on my new battery.
A few observations:
- Interestingly, the battery reading in the MMI was about 30% before and after I replaced the battery. It wasn't until I reset the battery serial # with the VCDS that it went up to 100%.
- My thoughts are that the battery reading in the MMI was never meant to give a reading based on current state voltage (…like a voltmeter would). But rather it is meant to give an indicator of overall battery life span given the monitoring of various readings over a long period of time.
- Resting voltage for my original battery was 12.1V. The new battery is 12.6V.
- Its pretty crappy given newer battery technology like AGM or VRLA (check these out if you aren't aware of them...), that we have to pay twice as much for an inferior replacement battery given the unique shape. I guess thats PAR for the course with these cars.
Cheers