I have a 2007 XC90. Is there any risk in installing a cut-put switch for the battery? I have a parasitic battery leak which we think is the SAT Nav LCD screen. Until I isolate the problem I need to manage 2 days of battery life. As a temporary fix does anyone know of any reason why installing a cut out switch directly on the live wire at the battery end would be problematic?

 

Not a problem - a rarely used BMW I owned had the same problem and I installed one of the pictured battery disconnects. Battery did not go dead after that every 2 weeks. Unfortunately your battery is not as easy to get to as on my old M3. You will have to reset the clock and the auto up windows every time you reconnect.

 

If you have a garage with easy AC access, simply hook the car up to a battery tender. $25 at NAPA Online...

 

We have a 2008 R design Xc90 diesel and we've been having ongoing issues with total battery discharge for most of the year. We had it to 2 auto sparkies who couldn't find any fault. They both kept the car for several days with no problem, as soon as we got it back within a day the battery wouldn't have enough power to unlock the doors.
I wondered whether the factory SatNav might be the issue, the screen kept rising up out of the dash of its own accord, so I removed the screen and unplugged the unit under the left front seat (right hand drive car, ex UK). Of course then the audio wouldn't work so I plugged everything but the screen back in.
No improvement.
We fitted an isolator like the one in the picture but then we had an issue with the alarm system going off when we isolated the battery.
In the end we put a battery charger underneath the floor near the battery and plugged it in every time we parked the car up at home. Not a brilliant long term fix.
After further research I found that this has been an ongoing issue with a lot of European cars for years, and it all has to do with the Sirius satellite radio unit. There's a loop you can get to feed the fibreoptics back onto themselves so your audio will still work with normal radio. I guess if you have a Sirius subscription you wouldn't have the issue?
The Sirius unit sits on top of the SatNav in our car. On other Xc90s it's tucked up behind the side trim panels ((not sure which side, or whether it makes a difference whether your car is left or right hand drive)
So, early days, but I hope I've sorted it out. Why it only started this year I'm not sure. The only thing that has changed in the car's environment is that early in the new year we got "smart " electricity meters put on our house, and I wondered whether they might be "waking the car up ".​​​