Why does the battery in my car go flat after a week if I don't drive it?

The battery in my Peugeot 308CC was draining frequently, especially in cold weather. I replaced the battery seven months ago but it still goes flat after a week if the car isn't used. Peugeot dealer says...

Range Rover battery problems

I've just bought a used (2004 model) Range Rover and heard beforehand about a simple fix to stop the battery draining every couple of days or so. I've had a "hedgehog" or "Porcupine" fitted in the heater...

Ford Galaxy battery drain

I own Ford Galaxy 1.6 Titanium X (2012 model). It has suffered from battery drain since I bought it in 2013 and the problem has never been solved. Any idea what could be causing this?