I use third party batteries (1750 seidio's) that I had used before w my incredible 1. You just have to cut the little corner phlanges/wings off and turn it upside down. Ive been using the like this since day 1. My wife still has a DINC1 and she still uses them after the modification too.
There is a thread w pics on how to do it somewhere in here. If the 3500 fit in your old DINC without a new door, it will fit in your new phone post mod.
