RE: Solar eBike - Initial Build Ideas
For a battery housing you could possibly find a Pelican weatherproof box that has a double seal and internal foam padding. It may require a small padlock to lock it but the boxes come in a wide range of sizes and are rather durable.
The solar panel(s) could potentially be mounted to a lightweight frame of some type of composite material. Perhaps even a large composite picture frame would work. You could optionally use a clear plastic in the frame to protect the panel.
Something to consider in your setup would be a charge controller and/or the use of blocking diodes to keep the batteries from feeding back voltage into the panel(s) once they are fully charged. The BSV20A is a decent and rather inexpensive charge controller that works great for 12-24 volt systems. I am not sure about the voltage on your bike or the battery bank(s) you are assembling so I am not sure that charge controller would be adequate or not for your needs. I am also unsure how the charge controller would work with the Lithium Ion batteries. You may have to get a charging chip for them to control the charge rate. I do not have much experience with Lithium Ions so I cannot offer much insight there.
This is something that I just thought off and although off topic it may be worth thinking about. Have you considered maybe using a small wind turbine generator mounted to the front (or rear) of the bike to generate power? I have a small ten watt one made by Pacific Sky Power and it does not require much wind to start generating power and the plastic prop is rather small. There are even replacement props for it that are constructed of carbon fiber that are extremely durable.
Just an idea I thought worth mentioning. I really like your project!
I like this idea a lot! Looks like I could harvest quite a bit of energy that way, since my average speed is 20mph.
Haha! Yeah it was a neat idea. I later thought that small wind turbines could be rather functional on the trailer as well.
So...last night I dreamed about your bike project some and as often is the case my mind came up with some interesting approaches.
I previously mentioned using a composite material to make a frame for the panel(s). This could be done with four pieces of PVC pipe or electrical conduit along with four 'elbow' (90 degree) fittings to create the frame. If you were very industrious here you could perhaps even get a large enough pipe/conduit to allow for the batteries to fit inside of them and essentially make the panel and batteries into a single mountable unit. You could also add 'T' fittings and more lengths of pipe to mount this apparatus to the bike. It would look much like a table with four legs that angle in towards the center where another set of four 'T' fittings, shorter lengths of pipe/tubing and 'elbows' (90 degree) fittings would make another square/rectangle frame that can be secured to the rear of the bike with u-bolts or other suitable mounting hardware.
A plastic box with a clear plastic lid could accommodate the batteries and also the panel could be mounted inside the lid of the box. There is going to be some voltage/wattage loss by doing this because of the sunlight being defused but given the right material I think that it would be marginal. Again it would make the batteries and panel into a single unit.
Another idea that I had was to use a child's bicycle seat mounted on the rear of the bike with the panel mounted to it and the battery bank situated in a box that is mounted in the seat where a child would normally sit. This option also makes the batteries and panel into a single unit. Plus the child's seat will already have all the mounting hardware that is needed to attach the seat itself to the rear of the bike.
I love that you dreamed about my project!
I like all these ideas, and the PVC pipe idea the most. I wonder how well the 18650s fit in the different sizes of pipes. I can see this being a nice compact solid system.
Great! Yeah I often fall asleep trying to solve things or invent things. I have gotten pretty good at getting my brain to dream about the ideas also. It is a strange way to solve challenges but it works well enough for me.
Yeah I had also considered making 'capped tubes' with PVC that you could mount on either side of the 'top tube' of the bike frame or along the 'down tube' or 'seat tube'. I think that doing it that way you could disperse the weight of the batteries in a way that it does not make the rear of the bike heavy.
All just ideas.
If you could design and manufacture the frame, I bet you could get all the batteries in there. It'd save space!
Yeah I thought of that as well actually but I was thinking it would make any maintenance on the batteries very difficult. That was what lead me to thinking of mountable external tubes with the batteries in them.
I'll be using a 54.6v MPPT Charge Controller. It boosts the 19v panels up to the max charge voltage of the battery.
I do think I'm gonna need to use a battery management system to keep the cells charged equally.
That sounds like a sweet Mppt charge controller. I am curious what make and model you use. I have been looking for a good one for my solar rig. The Outback ones are what I am leaning towards but they are pricey.
From everything I have researched about Lithium Ions charging them equally is vital.
Ya, I have an old lithium battery pack I made which doesn't work well anymore due to long term imbalances.
The controller is the Genasun Boost 8.
Oh Wow! That is some really neat technology for a charge controller. Never saw anything like that. So neat!
Yeah I have avoided Lithium Ions for simplicity's sake.
Thanks for the information on the charge controller.