This only applies if you have a Windows Mobile phone (Start menu, etc). If you do not, ignore this entirely. I assume so because the model you state is that of a battery for WinMo phones.
You seem to have found vGBA - this is part of a program called MorphGear. You do have to either buy or use the trial of MorphGear and its sub-emulators (there's GBC and SNES and such too). MG is decent but not the greatest; it's worth a try if you find games to not work in other emus.
The best two worth looking at are PocketGBA and GBACE. They both have decent compatibility and speed, but it can vary by phone; you may need to do some tweaking of frameskip and screen setup. There are a couple others, but they are not really needed. These big three (PocketGBA, MorphGear, GBACE) will cover most everything.
The main issue you will deal with is your phone - you might not have the speed or the RAM to run certain games. As an example, if you try to run Doom or any other FPS, you will completely fail in most cases. Try a few and you will probably find many that work well.
