bluezomo

I am planning a high-class trip from Southern Iran back to Europe with an e-bike and a trailer that can be used like a camper. The trailer will extend to 2m in length and host a little tent so I can camp wherever (yes, sometimes illegally).

In addition, I aim at solar charging. There are kits available like Jackery EXPLORER that cost €1000+ but have 200W solar panels and 1000Wh capacity.
However, there are drawbacks with such a system: There is a substantial loss of power when first charging the power station battery and then using the DC/AC transformer to get 230V and using the e-bike charger to get 230 AC down to DC 48V (or 36V, etc.).

Options/wishlist:

1. An adaption/device so that the e-bike battery can be directly charged with DC from the powerstation
2. A "direct mode option" so that the power from the solar panel goes directly to the bicycle. For long roads/high sunshine sections ...
3. Using the powerstation as an e-bike battery skipping the transformation/battery-to-battery charging.

I have some ideas (short-wiring the DC output from the power station to the DC input of the charger, short-wiring the DC output of the solar panels to the e-bike input with voltage protector, etc.) but no experience. I don't want to reinvent the wheel ...

• Does anyone have experience in these fields?
• Are there other powerstation&solar panel kits that fit well for e-bike touring?
• Does anyone know about trailers that are "campers"?
• Other things about e-bike traveling? (I did some but only from hotel to hotel ...)

Mike_Kelly

You must be very careful!!
Lipo batteries can explode if they are not charged properly and at the right voltage. To charge directly you need a "boost mppt solar charge controller" made to charge lipo batteries. You need to know the voltage of your ebike batteries. It is not efficient to charge a "power station" then use it to charge the bike.Lots of info on youtube. Read it.

bluezomo

What about charging while driving? Is this depending on the ebike or is charging while driving or using solar power directly when driving always supported?

PoweredByVeg

It’ll probably be difficult to get enough power to juice up the batteries - think 1kW of panel which is many square meters, and takes time. For charging just use standard equipment, sure there’s losses but that’s physics you’re not going to avoid. You’d want maybe a kWh of bike batteries to carry you and all that gear. But depending on your trailer maybe you could get away with 200-400W while you bike. You’d want a buffer, so I’d just get an off the shelf battery like they have these days that outputs line voltage and has solar MPPT in. Charge that while you bike, then at night charge the bike off that.

More interested in this “high class trailer” idea you have.

2old

An individual who posts here did something similar several years ago; perhaps he'll respond. Also check ebikesca; there was a story about a European trip.

cat0020

You can get some ideas here:

Ebikes & eRecumbents with solar backup across EU

Mike_Kelly

It has been done by a few for a decade or more. It does not require a 1kw panel either. See the Sun Trip videos on youtube for ideas.
https://www.thesuntrip.com/en/the-mo...e-solar-bikes/
A person in the US Mark Havran built a solar trailer with no storage and cycled around the US and to Alaska.
https://solare.bike/author/markhavran/
So it is possible but not with a Power Station. You need direct connection via a mppt boost solar charge controller and you need to know your bicycle battery voltage.
Drew Builds Stuff

bluezomo

I found a youtube clip explaining how to charge a Bosch e-bike during cycling. Does anyone have experience with that? I was looking for an ebike and Bosch is quite frequently found in bikes.
its on youtube ... watch?v=EnSRNZDXE60 (can't post links yet)
I would like some more information before I buy a Bosch ebike.

veganbikes

Bosch bikes are extremely reliable and easy to get service all over the country and the world though it should be of minor note the U.S. cannot do warranties on motors for EU bikes and vice verse but the amount of times one would need to replace a motor is almost never. In terms of charging while riding I don't know how one would do that realistically but I guess maybe if your port was in the right place and you had a generator or some way of creating power maybe it could work but it would sure be a hassle. I have two 625wh batteries so I really don't need to worry too much about needing charge and can get a decent charge in an hour so if I was on tour I could just easily stop and grab lunch and charge for a bit and if I take time and enjoy life an hour will go by quickly. I could also potentially carry any extra set of batteries and swap them in and out as needed but about 150-180 miles in range in eco mode is quite a distance and not one I would probably want to do in a day.

Would be curious to see the link if you get active in the many wonderful current threads going on throughout the bike forums you will get to the required 10 posts and can post links and pictures quite easily.

bluezomo

I have a Bosch charger from the last ebike. Option to adapt it to charge a second battery while driving (or both when resting). Does anyone have knowledge to tweek the Bosch charger to feed DC into it? It should not be magic.

Robert C

I am getting ready to rebuild the whole thing by placing the panels on a trailer and using a rotovelo, I just got annoyed with the project because of some trouble I had with the ebike.ca 5-speed hub motor that was dead out of the box. Also come things have changed, eating into some of my "fun" time.

That said, yes, this was me:



. . . and yes, I was absurdly overloaded

You will need a DC-DC charge controller, yes, they are expensive, but you will fry your battery, at some point, if you don't have one. As you note, there are just too many losses to go DC>AC-AC>DC

I used:
Two 140w Flexible Solar panels and a GVBoost GENUSUN WATERPROOF 105-350W 56.8V LITHIUM BATTERY SOLAR CHARGE CONTROLLER. Keep in mind, my plan had me going over the Rocky Mountains

I also used a Nu-Vinci hub, which is nearly ideal for this application, you can "trim' the current draw very precisely by adjusting the transmission. This called for a crank motor. I also ended up switching, mid-trip, to a set of BMX chains. The regular bicycle chains kept breaking on steep hills.

bluezomo

Thanks for answering. The tricky part is still the ebike that can drive while charging or charge while driving. The boost MPPT and the solar panels are ok, that stuff you can get from Grin technologies, or else.

Robert C

Not at all, the charger controller connects to the battery. the Motor Controller also connects to the battery. Both are connected to the battery at the same time. As such, there is no issue with charging and driving at the same time.

bluezomo

I don't get it. When I have a e.g. Bosch motor, the Bosch electronic prevents driving when charging. It also prevents charging with a non-Bosch charger. This might work for self-made ebikes but not for proprietary models with Bosch or Yamaha motors and electronics.
Or how would you do it for a Bosch bike?

Robert C

You have me at that one. I know next to nothing about the Bosch system. I can suspect what would work, but I don't have one to look at. So I don't know if it would. As you can see, mine was a self-build.
Sorry I can't be more help.

Mike_Kelly

It is complicated. If you connect one charged battery to an uncharged battery you can destroy both batteries and cause a fire. So ebikes that are designed to have an external battery have a switch built-in that senses that state of the two batteries and turns one off until they are at a similar charge.
So some vendors will turn off the internal battery if they detect an external battery to prevent problems. Hence the solar panel will never charge the internal battery. Some charger ports are only designed for a low current charger and can't be used to supply large amounts of current directly to the motor.
They are all different.
I think in the DIY world you are better off with a Bafang motor because they sell to DIY people and you will find more people doing self-built projects that might be of assistance.
But don't hook anything up unless you know it works.

MarcusT

I have no experience with charging while riding, but if it is a Bosch system, it may be near to impossible because of the computer set up. Bosch is very, very proprietory. You may need several technicians to get something feasible.
I would consider getting a generic hub motor. Easy to set up, batteries can be found any where, charging is much simpler. And in case of dead battery, pedalling is still resistance free.
Mind you, I have no experience in world touring with an ebike. But I know that current Bosch is impossible to service, repair or hack in many parts of the world.

bluezomo

New idea: I take off the battery simulate the battery with an external system, solar charger, boost mppt, and external non-proprietary battery. I.e. Where the battery connects to the bike, I solder cables and provide the power. For the rest I could use a Grind technology set and a Swiss battery (speedped).
Unless there is an electronic that detects the battery (control channel on the battery) this should work. The boost mppt and some electronics could supply the exact voltage to the bike.

Pop N Wood

All plug in chargers take the AC power and convert it to DC to before regulating it to the battery. It seems completely doable to take a commercial charger and convert it to some sort of DC input power. The challenge might be generating a steady source of power from the solar panels.

Having said that solar panel controllers do exactly what you say, manage solar panel output to safely charge a battery. I would bet there is an existing product already available to do what you want.

I think the biggest limitation will be getting enough solar energy to actually keep the batteries charged. Hooking up a trailer and solar farm is going to add a lot of weight. This means driving on electric assist more often than not. This will suck up a lot of juice. My guess is a 1 kw panel will be woefully inadequate. Yes, you can build a system with smaller panels, but that limits the range of the electric assist.

The other thing to consider is charging while riding simply won't produce much energy. You won't be able to deploy much solar area and what you have will be in and out of shade or not pointed directly at the sun.

2old

If it can be accomplished, I'll bet Justin at ebikesca did it while touring Europe a couple of years ago in a "tandem" with his girlfriend (now wife). You might look up the details of the trip. They might even have a product(s) that will facilitate your "system".

cat0020

Interesting concepts from competition:

RoulezTandem

Look into DC to DC converters

Robert C

Don't bother converting it to AC just to convert it back to DC, each and every time you "change" something, there are losses. Get a solar charge controller to the same voltage as your batteries. No, they are not cheap, but it is the right answer.

You will need a battery. You will be both charging and drawing from it. However, without it you will be overpowered at times and underpowered at others. You will have severe trouble with any hill or tree cover, it just won't work.

Next, I had about 350W of solar panels. I had ammeters (gauges of current flow) for both in from the panel, and out, to the motor. By mu calculations, I was able to hold 13 over level ground and charge at the same time. in practice, I was generally able to go faster than this. This was an ideal application of the NuVinci IGH as it allowed me to carefully trim my power draw.