Like another reviewer here, I got this with specific intent in mind - keeping what I expect is going to be a lightly used motorcycle's battery charged while it sits semi-neglected waiting for me to have some more free time and cooperative weather to take it out for a relaxing ride.  Since I've become a fair weather rider and am more cautious about taking a motorcycle out on overly crowded roadways, the motorcycle that I own is going to be left sitting for longer periods that I'd like, leaving the battery to slowly drain, which leaves me a few options to keep the battery ready when I am finally ready to use the m/c.I could pull out my old plug-in charger and let it sit like the vampire that it is while it provides a trickle charge, or I can make use of this device to use the free sunshine to get the same results.  Not that I expect a trickle charger to pull that much electricity, but given that I've got a house full of electronic items and with each monthly electric bill I see a reminder that my home is pulling more than twice what my neighbors do (which neighbors they are actually comparing to is something I wonder, but that's a different story for another day) and I feel like I'm paying more than I otherwise might need to (uh, gee, would that electrical usage also have something to do with two young ladies in the household, my wife's daughter and my own daughter, and their usage of hot water in the showers to wash their hair, followed by the use of the blow dryers to dry their hair, etc.) I figure that I should probably do what I can to avoid using utility company provided power when possible.Heck, I wish that solar power would come down in cost even more and that I could power things like the water heater and the blow dryer with solar, but the panels are still costly and the number of panels needed is still higher than I'd like so I'm back to using devices like this one which work fine for the types of purposes they are designed for.If you don't ask too much from it (or expect too much from it) it is a very useful device.  Don't expect it to power your home or even power a single device, but do expect it to be useful for keeping a battery charged.