Battery woes

[WhyTwo]

Not used the car for approx 6 week, mainly due to being away and the terrible weather, but have had it on an Accumate the whole time. Unplugged the Accumate from the mains to charge something else and forgot about it overnight. Next day I plug the Accumate in and the Accumate tells me the battery has gone from 100% to zero overnight ?! Could just about arm/disarm the alarm, faint flashes of the indicators, but couldn't open doors/boot

Charged it on the Accumate overnight and it's saying it's 100% again. I think the alarm was left off and the car therefore unlocked but I can't open the doors and now can't arm/ disarm the alarm.

So two things a) can somebody PM me the way to get in. Assuming it's pretty similar to the Tuscan but haven't had the chance to look yet b) why has the battery discharged over night on a mild night having shown no issues prior to me parking it a few weeks ago? I've had no battery or alarm related issues since I've had the car (almost a year) and when I put the car away everything was working just fine. What could've changed?

[PuffsBack]

Probably the battery, they do die very quickly these days. My Disco has been fine for a couple of years then a month or so back ago the battery died literally overnight. Started the car fine, took it for a drive, stopped at the shops and then nothing. I was convinced it was the alternator but nope it was the battery.