To ask how much electricity my empty flat needs

[harderandharder2breathe]

I'm going away for 2 weeks, I have s prepayment meter so need to make sure there's sufficient credit that it stays on but as it's just before payday I don't want to put more on than needed

It's a small 2 bed flat, I'm going to turn the water heater off the only thing I can think of that will be left on is the under counter fridge/freezer.

Any ideas how much credit I should leave on it? I have emergency credit as well but won't be around to activate it and I don't think it will kick in without being activated by the payment key.

[Charlesroi]

If you are on a reasonable tariff the standing charge is about 25p a day, so budget £2 a week for that.
If you are sure it's only the fridge/freezer then I reckon you'd get away with £10. Maybe put £15 on to be on the safe side.