It really does seem to be a tiny battery! 😞
I've had issues with it from having the car valeted, doors open long enough drains it.
Also my Blackvue camera in parking mode killed it, even with the option to turn it off with low battery. I think it just drops too quick for the camera to sense it and turn it off.
So had to turn that feature off which is a shame.
I became an expert at the manual unlocking of the doors, and now have a battery pack in the glovebox just in case - Don't put it in the boot, can't get in if battery dead 😄