I am building myself a solar trailer for my e-bike for touring Europe next summer. I want something like the one in the picture below:
It doesn't need to be a perfect setup. I don't want to break any records, nor spend all my money on it. I just like the freedom of touring without being bound to grid electricity all the time. I'm not the most technical dude, so I prefer to keep it simple.
I bought a bike trailer, solar panel (100 watts , but I will buy another one) and a boost charge controller (genasun GV-8 / 42v)
My bike has a bafang mid drive (250w) and at this moment I have a cheap aliexpress 36v (17.5 Ah) battery pack.
I have read how other people done this, and it seems I got two basic options :
1. Two batteries Probably the most simple setup. Just buy another cheap aliexpress battery pack, and charge 1 battery pack while I ride (or camp) on the trailer , while the other is connected to the motor and used for riding. I have come up with this list of advantages / disadvantages:
- double my range (if I am able to charge both packs on a campsite)
- reserve battery (in case my cheap aliexpress pack blows up)
- It's simple. Not much wiring and soldering
- heavy. I have to drag along an extra battery
- less efficient ? Power probably get's lost while charging (instead of the motor using it directly)
- A bit more expensive, have to buy two batteries (but my batteries also last two times longer)
- I have to manually switch the batteries / monitor my charging
2. Charge while riding (only 1 battery) I think most people do it this way, but it requires more work and technical expertise.
- Probably more efficient (power the motor directly from solar panels?)
- No switching of batteries
- harder to build, more technical knowledge needed. Have to run wires all over my bike and open up my battery pack to make a connection(input port) for charging
- I've heard it could mess up the BMS of my battery pack (resetting it all the time). Maybe my cheap aliexpress pack can't handle it very well? Then I probably have to buy an expensive battery.
That's what I could come up with for now. What do you people think about the list? What would your advise be?
I appreciate any input.