https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1
I bought one of these to monitor the electric consumption of the electric car I recently purchased. The car isn't seeing much use so it only goes on charge about once week.
I keep a note of the distance covered and record it against the kWhs used to recharge the batteries.

The strange thing is the meter records usage when the car isn't being charged.(i.e.) last week after recharging the meter read 73.65kWh. This morning when going to recharge the car again the meter read 74.16kWh so where did the 0.51kW go ?
Gremlins
Is my neighbour plugging in extension lead ?

It just questions my faith in the meter.