Run out off electricity here too
The Mazda has a comically small battery which seems to be good for around 3 weeks parked up before it loses the enthusiasm to start the engine - and that presupposes that the battery was properly charged in the first place.
We have been in lockdown for 8 weeks now, the car gets an occasional short run to buy heavy or bulky essentials (beer, wine, toilet rolls). After 3 weeks it failed to start so I hoiked the battery out and charged it overnight. That got about 3 weeks. I ran the next charge until the charger said it was fully charged and that lasted about 10 days.
It is on charge again now and has been since it failed to start this morning . Charger claims that it is fully charged. Just checked with a voltmeter and it is sitting at 13.85V. Going to leave it overnight and see if that achieves anything.