Originally Posted by
cblaisd
Do those cases wear out or get less effective over time?
Yes. But you don't use them as much as your native battery, so it isn't as much of an issue. You turn the Mophie "on" only when your phone is getting low.
Originally Posted by
cblaisd
Does anyone make a >2400 mAh internal battery that can be put in the iPhone?
I installed a larger-than-stock battery in my 4s, but it really hasn't made much difference.