mrmelo2

I have a dead battery in my 2007 Q7 and have purchased and installed a new one. I'm using a memory saver plugged into a mobile power pack to retain important settings. All seems to be working fine with that. But, when reconnecting the battery clamps on the new battery (positive first and attempting negative second), sparks begin to fly!!!!!!! The first connection doesn't cause any sparks, it is the second connection that sets off the sparks. All the YouTube videos I've watched do not encounter this problem? I pulled the clamp away immediately when sparking appeared and hope that nothing got fried. But I've stopped the job until I can get some help. CAN SOMEONE PLEASE HELP ME OUT HERE???????

lentiman

Its not abnormal for a battery to spark when you connect it.

Cliff68

According to the first response, it’s normal for the terminal to spark when reconnecting, but I would usually connect the negative (ground) first!!
I have a question though- if you don’t use memory saver or a continuous 12v supply while your battery is being changed, or dies on you, what’s the outcome? Would you have to use VCDS and reset everything?? Or just some settings?

dreadlocks

a battery does not have a disconnect switch, its posts are always hot so it arcing when connecting is completely normal and nothing to worry about.

If your ECU looses power all the learning the ECU has done is lost and you'll get poor fuel economy and power for half a tank of fuel or so while it re-adapts on its own, you might also loose other settings like radio programming, seat programming, etc.. no VCDS or anything needed however.

mrmelo2

Hey Cliff68, Thanks for your response! I managed to get a good 12V power source for the Memory Saver and brought the voltage on the bus closer to equal with the new battery and the sparks went away. All appears to be well. To answer your question everything I view/read points out adamantly that you should always preserve the memory when disconnecting your battery to prevent loss of presets (like radio stations, seat positions, etc...) and ECU settings which could affect how your Audi performs.

mrmelo2

Thanks for your response lentiman. Please see my response to Cliff68 below so that I don't have to type it all again But thanks for taking the time.

mrmelo2

Thanks for your response dreadlocks. Please see my response to Cliff68 below. Everything appears to have been preserved, new battery installed, car is running great and I'm a happy camper! Thanks for taking the time.

Cliff68

Glad you got through Mr Melo and all is well. Thanks dreadlocks for the info as well 👍.. One of the reasons I asked about no power is that it appears that I have lost Bluetooth functions on my Q7, and someone said that I should disconnect the battery power for about a minute or so and reconnect, and it should reset the Bluetooth module, but I’m a little skeptical about that!! I had sent a query last week regarding this... I have a 2010 Audi Q7 3.0 TDI right hand drive, but for the hell of me can’t locate the Bluetooth module!! People say it’s under the driver seat in a black box, but I’ve looked and there’s nothing like that!! If I could just locate the module I can bypass it alone, and probably replace it without disconnecting the battery. Some say it may be behind the glove box... any ideas?? Just locating the bloody Bluetooth module is frustrating me 😡

chingwodapigu

After replacing your battery, iirc, you need to use VCDS to code the new battery to the car so that it charges correctly. If you don't do this, your new battery will be charged improperly and will get ruined.

Up-it

Hey Cliff.

mate i have a RHD as well but didn’t go lifting the drivers seat but i did have a quick look by powering the seat all the way forward and then up. It looks like the maybe the Bluetooth module is there along with the trans ecm. Its kinda under the plastic cover and goes under the rear passengers carpet. As for the battery, who cares if you disconnect it. I just had mine disconnected for 8 hours while I worked on the engine and placed the cables back on. All good just need to reset the time and re-sync the iphones and all is good. So maybe its worth dropping the passengers seat back and disconnecting the battery for 30mins just to reboot the Bluetooth module.