Running and charging

SIR – I agree that drivers should be banned from sitting in their cars with the engine running while waiting at the school gates (report, June 30).

When walking to collect my grandchildren from school, I have noticed that most of the drivers who do this are tapping away on their mobile phones, which are plugged into the auxiliary power (cigarette lighter) socket, presumably to charge their phone battery.

I believe that charging a phone will only drain a small amount of power from a car battery, so there is no need to run the engine, but I suspect that in many cars the auxiliary power socket does not work unless the car ignition is turned on.

If people cannot be bothered to recharge their phone at home, perhaps car manufacturers need to build in a system for charging them without the need to turn on the car engine. Ian Burton

Hemel Hempstead, Hertfordshire