2014 xc60 R Design Premier Plus
 

Hello,
A buddy of mine has a 2014 XC60 R-Design Premier Plus he is selling and it has 95k on it and wanting to know if there are problems I need to be aware of? He is the only owner and is very meticulous so I am confident it has been well maintained. One current issue is it has sat for a bit and it doesn't start. Like the battery is dead. AAA came and jumped it and he drove for 40minutes and then a day later went to start and nothing. Took to the dealer they had it overnight and said battery was 91% and good. No other issues could be found? The alarm horn goes off though?
Any insight would be awesome!
TIA

UPDATE. Replaced battery and all seems good now. Put a volt meter on the old battery and it only showed 2v.

UPDATE: Problem still happening after putting in a new battery from Batteries Plus. Went back to dealer and they said aftermarket batteries can cause issues and that a Volvo battery is recommended. New Volvo battery installed and complete system check for power draw. Nothing found. This was 1/6/22. Today dead again!
Heading back to dealer. What else could it be? I can't believe two new batteries each have an issue.