I have my SII equipped Starfire set up without a 1/4 battery powered option, both for ease of wiring and because of the battery life problem. But, I've discovered Panasonic Eneloop AA batteries, which last longer than alkaline AA batteries and can be recharged thousands of times. They also hold a charge for a very long time without being used. So, given that the Starfire has a lot of room in the interior, I'm thinking about rigging up a battery pack out of AA's instead of 9V's. Just a thought at this time.