I usually use wifi at home on my iPhone 4s. Sometimes, though, everything goes real slow over wifi (at certain times of the day something seems to interfere with our wifi - even on the computer). When that happens I switch my phone to 3G and everything goes much faster. I use my phone a lot and am always trying to conserve battery life. I can't seem to find an answer: does using 3G drain the battery faster than using wifi? Or does it make no difference? Thank you.