I've been lurking for the last couple days, but this is a topic I can contribute to.
I actually have one of their smaller units (the "CampStove" as opposed to the "HomeStove") and I can tell that it works wonderfully! The battery actually never gets that hot because it's heat shielded and has a heat sink on it... which of course wouldn't solve the issue on it's own, but there is also a built in fan (powered by the thermocouple) which blows through this heat sink and keeps the battery cool. This fan is also what allows the small "can" design to burn super efficiently, because it acts as a bellows, raising the heat level and encouraging a more complete combustion. It's also a *ton* easier to start, since it can use the power in the battery to run the fan on low, effectively "breathing life" into the embers as you try to get it started.
It takes about 5 minutes for it to be generating enough heat/power to output the power over the USB, but once it gets there, it will charge my phone of kindle without an issue, just keep dropping sticks in. I have not tested how long I actually have to charge for to bring either item up from "dead" but the iPhone in particular is very picky about it's power source, so I'm quite impressed they managed to provide such a nice steady power stream from a camp stove.
- Justin
