Great, but better chargers can monitor voltage so the battery really won't overcharge at all. Last thing you need are problems because you went the budget route charging a 9v battery.
If you want to set off and go develop some grand new thing, you don't need millions of dollars of capitalization. You need enough pizza and Diet Coke to stick in your refrigerator, a cheap PC to work on, and the dedication to go through with it. We slept on floors. We waded across rivers. -John Carmack