Searching for an ebike to pull a trailer with at least 2 solar panels?

Tom in Kingman

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Greetings, I am looking at a multitude of options for my very first E-bike. I have grandiose plans with zero knowledge. I want enough power to pull a trailer with at least 2 solar panels mounted on top so as to keep the batts charged along with the batteries and some prospecting equipment. The trailer will be about 8 feet long. I am thinking solid tires all around and a front wheel motor.
 
You've probably already found answers to your question, but I thought I'd point out that it might be best to use a rear wheel motor rather than a front wheel motor. I think you'd run into traction problems with a front wheel motor when towing uphill on rough surfaces.
 
I hate to burst your bubble but solar panels are not going to keep your batteries charged while riding.
Even if you have two 200 watt panels (which are huge) they are going to have to be both facing directly at the sun both compass and elevation to get anywhere near their capacity.
According to the display on my bike I consume 700 watts to travel at 20mph with no trailer.
Also keep in mind that solar panels are quite fragile and can be damaged easily by shock and vibration.
If what you want to do was feasible you would see solar trailers everywhere you went.
Solar panels can be very useful for charging (for hours) while stopped.
I wish you every success. Keep us posted.
 
The other not-mentioned factor is large panels act as a sail, and can flip the trailer over. They are best used for stationary charging if they are large.
 
Greetings, I am looking at a multitude of options for my very first E-bike. I have grandiose plans with zero knowledge. I want enough power to pull a trailer with at least 2 solar panels mounted on top so as to keep the batts charged along with the batteries and some prospecting equipment. The trailer will be about 8 feet long. I am thinking solid tires all around and a front wheel motor.
Wondering what equipment/ weight you'd be towing in your trailer? I don't think it would be practical to expect that your trailer would be able to support enough panels to keep you fully charged while you ride, but you could certainly extend your range. You could be recharging while you prospect. A lot of your questions can't be answered until you place some range and weight boundaries. If you're serious about this, don't skimp on battery. Overbudget for your range requirements due to the unknown nature of the terrain you'd be riding in.

They make flexible solar panels which you could lay flat on top of your load to help with the sail effect addertooth mentioned. I dont't know what the biggest wattage flexible panels are, so you would need to look into that and do some math. You could also deploy higher wattage panels when you arrive and orient them for maximum charge effect. You'll need to carry some sort of charge controller and/or inverter to hook up to the panels and recharge your batts.

Towing will put a big drain on your battery. It would be wise to consider multiple batteries or a reserve one. You'll want your trailer to have good ground clearance, be nimble, and be loaded to balance with your bike. May want to think about 2-wheel drive and extended range ebikes. It won't be cheap to do it right.
 
I hate to burst your bubble but solar panels are not going to keep your batteries charged while riding.
Even if you have two 200 watt panels (which are huge) they are going to have to be both facing directly at the sun both compass and elevation to get anywhere near their capacity.
According to the display on my bike I consume 700 watts to travel at 20mph with no trailer.
Also keep in mind that solar panels are quite fragile and can be damaged easily by shock and vibration.
If what you want to do was feasible you would see solar trailers everywhere you went.
Solar panels can be very useful for charging (for hours) while stopped.
I wish you every success. Keep us posted.
These days you can buy flexible panels that curve to catch at almost any angle. Some are considering covering entire motor car with them.
 
Greetings, I am looking at a multitude of options for my very first E-bike. I have grandiose plans with zero knowledge. I want enough power to pull a trailer with at least 2 solar panels mounted on top so as to keep the batts charged along with the batteries and some prospecting equipment. The trailer will be about 8 feet long. I am thinking solid tires all around and a front wheel motor.

What did you end up getting, Tom?

I'm thinking even with a cockamamie plan like this, it would be done 4+ years later. ;)
 
Wish this guys was still around, he and I have similar ideas. I fully expect that one 200 watt panel will extend the range by huge amounts if one also pedals. With todays much lighter flexible panels coming in at around 10lbs. for a 200 watt panel there's no reason a trailer couldn't carry enough to keep the power levels up on sunny days. As thin as they are one could stack them several deep like sheets of paper and spread them out when stopped...
 
Just remember that it's an infinite loop: You want more power to haul more stuff. More power costs more money and weight. More power needs more charging power. So haul the solar panels too. You'll essentially be riding an electric truck around, which may be novel for a bit, but once the new wears off and you figure out how much money & time you've wasted, it might not be worth it.

Just my opinion, I'm not as adventurous as some!
 
Don’t forget that very few BMS allow you to charge while riding.
I've been living off grid for almost 20 years and that's pure B.S. from MY personal experience! I will grant I haven't tried every type of BMS but none of mine are bothered by charging / discharging at the same time.
 
A curve will only ensure that the panel operates at less than peak efficiency. Only the portion of the panel that is perpendicular to the sun will peak.
Everything comes with advantages & disadvantages.
Our intrepid adventurer needs portable lightweight solar power generation - flexible panels will provide that. The slight drop in efficiency is inconsequential to paramount necessarily of lightweight portability.

 
Everything comes with advantages & disadvantages.
Our intrepid adventurer needs portable lightweight solar power generation - flexible panels will provide that. The slight drop in efficiency is inconsequential to paramount necessarily of lightweight portability.

But it won’t be a “slight” drop in efficiency, it will be a greater than 50% drop in efficiency.
 
I've been living off grid for almost 20 years and that's pure B.S. from MY personal experience! I will grant I haven't tried every type of BMS but none of mine are bothered by charging / discharging at the same time.
I will bow to your greater experience.
All I know is that my bike (unknown BMS) will not power on if the charger is plugged in and energized.
If your solar panel is connected between the bike and the battery then it is like a second battery and will supply current to the bike if the voltage is equal to or greater than battery voltage. While useful that is different from charging.
If your BMS does allow charging from the discharge port that would pretty much bypass any BMS charging protections.
 
I will bow to your greater experience.
All I know is that my bike (unknown BMS) will not power on if the charger is plugged in and energized.
If your solar panel is connected between the bike and the battery then it is like a second battery and will supply current to the bike if the voltage is equal to or greater than battery voltage. While useful that is different from charging.
If your BMS does allow charging from the discharge port that would pretty much bypass any BMS charging protections.
None of the BMS's I've wired up had separate terminals for charging / discharging all is done through the same two wires. My "guess" is on your battery there is another circuit causing this that connects the charge port to the BMS.
 
How then do they provide overcharge or overvoltage protection without a separate charge path?
Every e-bike I have seen has a separate charger port.
 
How then do they provide overcharge or overvoltage protection without a separate charge path?
Every e-bike I have seen has a separate charger port.
That's a great question and one I can answer. A BMS has a series of small wires going to each string of cells this is the circuit that reads the charge and moves power between cells.
 
It will still need separate isolated circuits for monitoring and controlling charge and discharge, if for no other reason than scale.
 
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