A few weeks back I got 'stranded' at the local shopping centre when the key fob died and I could neither lock or start the car.
Fortunately for me, as I was at a shopping centre I could go into the nearest shop (leaving the car unlocked
) and buy a replacement CR2025 battery despite having spares back at home.
Bought new battery, but try getting into one of these so called blister packs without scissors or a knife almost proved impossible. Only brute force with house keys got it open.
Managed to resolve it, and my own stupid fault as the car had warned on the dash to replace battery, but only a few days warning before it went!
Morale of the story, replace that battery asap to avoid massive inconvenience.
Battery only lasts max 1 year with keyless.