Pumping Up

Preparation for towing the caravan includes loads of pumping up: caravan battery, caravan tyres, car tyres and here the car's battery.  

The battery wasn’t flat, but I now understand that the car's charging system takes the battery up to only 80% charge, more than that being a waste of energy. But if I’m towing the car's system charges the caravan's “leisure” battery (and runs the fridge), an extra burden on the engine which will increase fuel consumption. But if I charge the car's battery as well it will reduce that burden. 

I think . . .

And we’re going only 30 miles down the coast, to Sidmouth.