My 98 S70 is great. But....

If the car sits for more than a couple days, the battery is completely dead requiring a jump or a charge.

The dealer said that the problem probably isn't the primary battery, but the rechargeable lithium battery in the alarm. After 15 years, the alarm battery might have lost it's ability to recharge so it syphons a charge from the main battery to keep working when the car isn't running. The dealer wants $700 for a new alarm and $700 to put it in. Ahhhh, no thank you. Apparently, the lithium battery cannot be replaced by itself.

I take it that disabling the alarm is not practical. I have an under the hood charger, which works, but i keep forgetting to plug it in.

Any suggestions?

 

mine does that too. I just bought the car the beginning of April, 2015. I just replaced the car battery, thinking that was the issue. The alarm has never gone off before, but today it did and I had a bear of a time resetting it. I finally had to put the key in the door and lock and unlock the door and it seemed to reset the alarm. I cringe to think that the alarm system might drain this new battery.

 

check out this Youtube vid - I think you are referring to the 7.2V battery sealed inside the siren box itself that is buried inside the fender...

 

I’ve got a v70. D5 2002 have a battery drain for last week. Can’t seem to find a leak on a circuit but seems when I remove the siren fuse it stops the drain no reading across the fuse to digest a drain Is this how the siren battery failure presents? I cant see a message come up on the dash for alarm siren service as the displays only now works intermittently !

thanks.