I haven't seen either with a charger, so your best bet is probably going to be rechargable AAs from Radio Shack or somewhere like that.
I settled on the LeapPad Explorer mainly for the camera, because DD3 has played with her big sister's DSi and loves the camera & doodle software on that so it is a fairly important feature for us. It is a Christmas gift, though, so I can't give any reviews from experience yet. DD3 was asking for an iPad scared1 because of the commercial with the little kid tracing letters on it, so we decided on the Explorer and the Mr Pencil game for a kid-friendly iPad-like experience.
If the camera isn't important to you, the VTech does have a couple of advantages - an SD slot for memory expansion and a MP3 player, which give it more room to "grow" with your child. For us that's not an important feature because DD3 can use one of the big kids' hand-me-downs when she develops an interest in an MP3 player, but it certainly adds to the InnoPad's all-in-one appeal.