"John Rumm" <see.my.signature@nowhere.null> wrote in message
news:45bd6691$0$8753$ed2619ec@ptn-nntp-reader02.plus.net...
> Dave R wrote:
>
>> I have one of those energy monitors from Maplin, my mobile phone chargers
>> use nothing when not plugged into the phone.
>
> It is worth noting that many modern phone chargers are switched mode power
> supplies. Many of these will in effect turn off when there is no load.
>

One test is whether it warms up at all when its not charging.