A myth has apparently been circulating over the last year which suggests that dialling 999 from a mobile and immediately disconnecting will charge the battery.
Derbyshire Police has today appealed to phone users not to believe this rumour.
A spokesperson said:
"There is no way any mobile phone battery can be boosted by anything other than a normal charger. We have received several silent 999 calls recently which have turned out to be people who are trying to get more charge on their phone.
Every time we get a silent or aborted 999 call we have to spend time ringing that person back to ensure they are safe. That takes up valuable time which could be spent dealing with a real emergency."