Got this in the mail for the Hampture Mk.III project some time ago, forgot to mention it here. This is the same battery pack that will be used to recharge the robot in the field. It plugs directly into the solar array out of the box and slowly but surely charges from it while the sun is out.
Since the robot will only consume a small percentage of its power every day, the solar panel is actually kind of overkill. But it needs to be, so that multiple cloudy days don't result in a dead battery. The array is 30 watts, exactly half of what is needed to fully replenish this battery pack in 8 hours (as much useful sunlight as you can get per day). I don't expect this to be a problem as the draw should be pretty modest; the pack only needs to power the charging dock, which will be in use intermittently, and the 4g mifi hotspot which is powered via USB and therefore will hardly add anything to the load.
If everything works as expected and I can find someplace to put all of this where it won't simply be stolen, it should work beautifully. You'll be able to download a program and use it to connect to the robot, steering it and seeing what it sees remotely even though it's off the grid. I am excite.