The unit ships from China so as you might imagine, documentation and specs are few and far between. In practical application, I ran it for an afternoon and the battery monitor didn't budge, so it appears to be pretty efficient. I'm hoping to get a solid weekend of service out of one 9.6v rechargeable battery. Going forward, I may add a couple of small solar panels just to maintain the charge in the drill battery but we'll see how this works first. This controller doesn't have "parking" and it's an "always on" scenario, this is another reason why I felt it necessary to add an on/off switch. Though it constantly monitors the sun's position, it doesn't use much power at all to do that, only when turning on the motor to reposition the deck. Even then, the duty cycle is extremely short, as it only moves the deck two or three degrees at a time. If power consumption is an issue, the TinyTracker HD has parking built in and is available in either single or dual axis. It runs a few post checks, positions the tracker then checks the sun's position every 10 minutes. More efficient but double the price.