Alfred Simkin and I are making a solar powered ebike charging station. We have worked out some of the electronics. We have two related projects in mind. The first is to make a semi-permanent installation. This will use 400 to 1000 watts of solar panels to charge a sealed lead acid (SLA) battery and then use a $40 DC/DC converter to have the 12v SLA charge a 36v or 48v lithium ebike battery. We plan to mount this system on a bike trailer (formerly IG’s coatrack/parade float; see attached sketch) so that it is moderately portable but it wouldn’t be suitable for touring. It will need to be staked down for long-term use. It will weigh 100 pounds or more. It could be towed by bicycle and set up on a lawn. We tested this system a couple of weeks ago and managed to partially charge an ebike battery with a single 200 watt panel, DC/DC converter, and SLA. We found the SLA was necessary to stabilize the voltage produced by the solar panel.
A second more advanced project will be to make a lightweight version suitable for long-distance travel by ebike. For this approach we plan to use a $300 MPPT solar charge controller that has settings for charging lithium batteries. We haven’t tested this yet. Ideally this system will be mounted on a custom bike frame.
The left top drawing shows two solar panels deployed. The array will need to be staked down. Both panels can slide right and left in a channel and rotate around the long axis. The top panel is on two posts that can be raised and lowered or removed completely. The two panels can be rotated to vertical for transport as showed in the lower left sketch. The right sketch shows the panel tray. The panels themselves don’t have a lot of structural integrity so the tray will need tubing on the long axis. Channels with clamps will hold the edges. A clamp holds the tray onto the trailer’s lengthwise beam.