Bullitt cargo bike with solar panels
I finally became a proper citizen of Copenhagen, Denmark… I bought a cargo bicycle! Now this isn’t any old cargo bike, it is a new take on the Danish Long John from 1923. Introducing the Bullitt from Larry vs Harry with a load capacity of 180 kilo, driver included. Now with all that room and capacity it is time to take my geeky projects outside and enjoy the weather!
One thing I needed was a renewable source of energy so I bought a front wheel dynamo, the Shimano DH-S501 Alfine Dynamo Disc Hub, which generates about 3 watts of power at 6v AC. This can output about 0.5 amps at 5v DC using an adapter to charge USB devices, but it is a bit on the low side. It also introduces some drag as you can see from the video, but nothing I can feel when using the bike.
So I decided to mount my Voltaic solar panels for a total of 30 watts of pure solar power!
The setup consists of
- Voltaic Fuse 10W solar panel. This also doubles up as a bag with easy access to the battery, adapters and cables for charging
- Voltaic Arc 20W foldable solar panel
- Voltaic V60 16.000 mAh battery. You might want to get the newer V72 battery which has a capacity of 20.000 mAh.
- Voltaic V60 barrel adapter
- Voltaic 5.5x2.5mm laptop cable
The battery is connected to the Fuse 10W and the Arc 20W supplies extra power by connecting it to the “Solar Panel Output” on the Fuse 10W. To do this I needed to use one of the included adapters to bridge the V60 barrel adapter with the Arc 20W and then the 5.5x2.5mm wire to connect the V60 barrel adapter to the Fuse 10W. Check out this guide for more information on how to do this. The above setup works nice for dedicated trips to the beach or a long bike ride where I need a lot of power. But there are a few drawbacks
- You cannot leave your bike out with all that gear, it will get stolen! So it does take about 5 min. to mount / unmount the setup
- The V60 lithium ion battery does not perform too well in the harsh and cold Danish winter. I might look into replacing it with a deep cycle lead acid battery that should perform better in all weather
- The angles of the solar panels are less than optimal
- The setup has to be adjusted when loading and offloading cargo
The next project is to change the setup so both the front hub dynamo and the solar panels charge the same battery and mounting smaller solar panels permanently on the bike.