I was told when brought my new NZ Mondeo Titanium that power is being used while the car is just sitting there (computer, alarm etc) and the battery will go flat after 1 month of non use. With Keyless entry thats a problem. I have my OXORD 360T Maximiser battery maintenance charger hooked on now and the battery will be in full charge for later. I had this OXFORD Maximiser for my Yamaha FZ1, Gen 2 Fazer 1000 Super Bike and worked great for that. I'm DJ NEZZ, The Kiwi from Auckland, New Zealand.

Newer Fords go into a sleep mode if not used for a couple of weeks to stop the battery going flat.

I have two trickle chargers for the cars that winter in my garage, one of which I built about 25 years ago, and another that was in the "Bargain Bucket" for £1.00 UK  in Halfords that works perfectly well.

I have previously used a solar panel on the parcels shelf plugged into the accessory socket - but in a modern car, that does not work because the car electronics would disconnect it !!

 

All you really need to do is start the car and let the engine run for half an hour every 4 or 5 days, that will keep the battery charged and also prevent condensation in the engine.

Or just drive it round the block occasionally, if you're not using it at all but we still need to use ours for food shops etc

Had to get breakdown AA to mine a week or so back. All kinds of error messages when I tried to start up. Turns out the battery was flat. Nothing wrong with the battery but his equipment showed something was draining it at a much faster rate than the normal little trickle after turning off. Now have to run the engine for a short while each day as I can’t get diagnostics done to identify the problem until they open up again.