Ed Rowe

I did a search and couldn't find a post on it....I have a 2008 roadster and got it about 9 years ago....the battery needs changed.. in the truck easy to get to but I've checked and it sounds like it's not as easy to just replace it like my other cars in the past ...You need to reset the codes? Is this correct?

If so I'll have my mechanic do it...

Vegas-roadster

No. I replaced the battery in my 2012 and did not reset any codes and had no issues. I'm not sure if all Mk 2s have a battery control module that needs to be reset. In fact, I did not know that ANY Mk 2 TTs had a battery control module that needed to be reset until recently. It wasn't mentioned in my 2012 owner's manual. If anyone on this board knows details about this, please share. This is what I DO know about Audi's that have a battery control module. The module extends battery life and saves on gas by adjusting its charge cycle to the needs of the battery. It has "smarts" so that it is adaptive. That is, as the battery gets older, it senses, adapts, and adjusts to the battery's charging needs. If your TT has a battery control module and you change the battery, if you reset the module then it knows that the old battery is gone and charges the new one accordingly immediately. If you don't reset the module, the adaptive mechanism of the module will figure out that that the charging cycle needs to be changed and will gradually do so over time. No one has ever posted what "over time" means. It could be a few car starts or 20. The effect of not resetting the battery control module is that the battery will be charged longer than necessary for a few starts. While this could theoretically shorten the life of the battery a little bit, practically the effect is negligible. This is particularly true if you replace the battery with the OEM. I did not use the OEM and still had no issues. Note that some aftermarket batteries advertised as suitable for the Mk 2 TT are significantly smaller in size and capacity than the OEM, so check measurements before you buy.

Ed Rowe

thanks for your detailed response...I`m ordering a Bosch battery...

meyergsr

I swapped the battery in my 2008 a few months ago without a reset or coding. I used a Duracell brand from Sam's Club which is made by Deka battery. No issues so far.
I have VCDS and could not even find a module for a reset. It doesn't exist on my car.

Ed Rowe

Thanks for the help..I changed it yesterday with a Bosch I bought from Amazon for about 100 dollars.....I live in Japan and they have Costco but not Sams...

It took about 30 minutes (easy) and car started fine today with no problems....everything seems to work fine...

Vegas-roadster

Relax. You might have to reset your windows for auto up-down but you will be fine.