I use this as a backup power source for my pellet stove. If the power goes out when the stove is on, you get a smoky mess since it relies on a fan for combustion and exhaust. I chose to go the APC route instead of the stove-branded unit - I feel more comfortable with a company that knows this business well. I could not be happier with it - fast switching, charges the battery fast after the outage too. Ultimately simple as well - the switch is either off, or automatic or charge-only. Set it and forget it!