Armrest battery
Main battery
From past experience
I’ve had 5 main batteries fitted and 1 armrest battery, all under warranty in less than 2 years.
Also I dont think your sticking door handles are down to the batteries, if it were they would all either not work at all or all stay in the out or in postion.
Again this is from my experience, I’ve had all 4 replaced under warranty in the past 2 years.
Your issue with the handles is more likely down to the known fault of water ingress into the handles sealed mechanism unit.
My guess is you have two separate issues.
Low 12v battery, either the main or armrest , but could be both.
Then you have the known sticking handle fault.
Welcome to DS .