i have switched to GiffGaff from Vodafone. After two days of use, i am experiencing dreadful battery drain.

I used to get to the end of the day with a bar or two battery left. I disconnected my phone from the charger at 6am and i now need to put my phone back on charge having hardly used it.

I have very poor/no 3G signal. Could this be the issue? Should i set the phone to GSM only?

If this continues i may have to switch to anohter network with better coverage.