In my 2006 S40, I just went out to the car tonight and noticed that the hands free bluetooth is lit up and flashing (asking to pair) when the ignition is off. I can turn on the ignition and pair my phone, but the hands free reverts to this behavior after I turn the ignition off. What I want to know is if it staying lit up all night will kill the battery? I can't find anything about it being constantly lit up in the Hands Free Manual. I also looked on YouTube. Otherwise, it has been working great - always ready to use when I start the car, but I very rarely drive at night, so I have not seen this happening. TY

 

I've not experienced this in a Volvo, but havewith an Acura. BMWs have also had it.
In these other cars the problem is that the BT module is searching for a phone to pair with. It should stop after a while but it doesn't. The current drain is relatively low, but persistent.
Will it kill your battery? The short answer is, yes. But the long answer takes into account all factors.
1) Battery condition - obviously a spanking new battery will last longer
2) Time elapsed between driving - if you drive it every day you will likely have les chance of a dead battery
3) Temp - extreme cold weather decreases battery power, so parking it outside in a Chicago winter may be enough.
4) The drain (in the Acira) is 250 milliamps. About 1/2 a non-led dome light.

My MDX would kill a fresh battery in about 3 days. And even after jumping and driving it would never have the same "reserve power". After a number of cycles it would kill it overnight. Disconnecting the module stopped the problem but of course I lost BT and all voice control. Replaced 400 buck module and all was still good.
Both Acura and BMW have denied the problem, both have class action suits, and both are successfully dragging it out so that they will not have to pay as the cars will no longer be on the road.

First, check the draw to get an idea of what sort of time frame you have, Then call Volvo (expect nothing). If the drain is enough to be troublesome *( I'm sure it is, eventually) then lookinto repair. I am unfamiliar with that module on your car, it may be a stand alone board and an easy replacement. Or Volvo may have integrated it into something major.

This is a good excuse to get a battery charger with the ability to have enough current to start your car as well. Even one of the portable rechargeable packs (pricey though)