I have an ordinary Anker battery, which charges my phone up to twice but then I bought a bigger Anker one. The charge lasts for for about 5-7 days, a bit heavier (12ozs) but I think well worth it.
Yes, good reminder about leads. I have to carry two leads, one for the charger, one for my phone. When will they standardise these things? My 3 pin plug is so cleverly designed, it folds flat when not in use, got it for a tenner when other sites were wanting £30.