Is it possible? Solar charge 96v EV while driving?

[Eldan]

Hi everyone, 1st post, found the community off youtube will prowse, hopefully someone here understands my crazy ideas lol

So I’m planning to build an e-motorcycle, 72v-96v system (haven’t finalized yet, I’m waiting on the order to test the speeds out)

Instead of order fairings(plastic coverings) for the bike cost like $150. I’m think of custom building a body or extension pieces out of solar to charge, so that I drive longer and charge on the go if I’m stuck.

The problem is how do I connect it to the battery without going through the basic process of (solar>chargecontroller>inverterDCtoAC>outlet>ACtoDC>96v Battery) I feel that’s a lot of wasted energy...But is it the only way?

I couldn’t find a 96v charge controller. So I was thinking to do (2) 48v mppt in series(if possible) to get 96v?
Or maybe separate the batteries into (2) 48v packs charge separately with 48v CC?(but that would mean A possibility of 2 different voltages when in series for the (2) 48v packs.

Some details,
I plan on ordering the qsmotor 17in 8kw, starting at 72v and incrementally increase your 96v as I’m comfortable with.(they say 60-80mph, I don’t believe them lol, so I will be testing it myself)

I’m not even sure there is a 96v charger, at least a fast one..
Any ideas? Also I can’t go too big on size b/c it’s a motorcycle, Because things are taking up space quickly, batteries, speed & charge controller, inverter, that are mostly large b/c of the high voltage. So is it possible to approach this 96v battery system with lower voltage to charge it?

Starting with SLA batteries for now, but will switch to lithium as I progress ($$)

Any inputs on any part of this project would be Greatly Appreciated!

Thanks for reading!

 

[Forbisher]

Forget about starting with lead acid batteries. Too much weight and not enough energy density for a motorcycle as well as many other problems.

You can not fit enough solar panels on a motorcycle (or car) to get any charging benefit.

Start of by getting an education in solar as to what is possible as your ideas are crazy.
Zero makes pretty decent electric motorcycles so look at those.

 

[Ampster]

The problem is how do I connect it to the battery

The real issue is how much surface area can you commit to solar without creating wind resistance or instability?
Answer the following questions and you may have a clue why this idea has not been implemented. It has been tried many times on paper and in real life.
How many Watts per square foot will solar panels generate per hour?
How many Watts per mile will your motorcycle consume?
How much time do you want to spend by the side of the road charging from the sun?
Connecting to your battery is simple once you get through the above.

 

[Trukinbear]

Lead-acid batteries, no way. Enough solar to make a noticeable difference in range, maybe if you tow a trailer with a fold-out array otherwise you don't have enough surface area to do anything beyond charging your phone. I tried to modify my Prius into a plug-in hybrid without a plug and came to the ultimate conclusion that if I could fold out 25 sq ft of panels, and maybe had an extendible mast with a wind turbine on it AND I parked it at the beach all day it still wouldn't make enough power to take me to town on a day's charge, much less back. I figured that if I could do all the above I would have added so much weight, and otherwise destroyed the aerodynamics of my Prius to such an extent even my most pessimistic calculations were probably way off as I was assuming the car to be as efficient as it was when I started out. Just covering it with solar cells can do little more than trickle charge your 12V coach battery, and/or operate a small vent fan (as Toyota has done).

 

[Ampster]

I plan on ordering the qsmotor 17in 8kw, starting at 72v

Once you understand the issues with solar panels and focus on the build, try Endless Sphere for good info on wiring a hub motor and available battery options.

 

[Eldan]

Thanks for the quick responses, I’m going to try to respond to all the feedback,

essentially, I know SLA are the crap or the crap, I have them laying around, so I was planning to test out what speeds each voltage produced, then order lithium cells accordingly.

solar wise I know it’s not “worth it” due to size & space. I was toying with the idea, order 50/75w flexible panels (thin) and Have them stored on the bike in a collapsible way. Which would open up into a big 20+ piece panel. Prob around 1200w, it’s not much, but probably a blessing if you went too far

so I could drive farther to the beach, leave it charging and be able to increase distance

I guess my question is

How many Watts per mile will your motorcycle consume?

I’m not sure how to find this out. I’m assuming that 1200w is peanuts to this.

the Prius is cool,read somewhere (maybe endless sphere or reddit) that someone did just that, and was able to handle15-20 mile (total) daily commutes on solar alone, which sparked this idea

Love endless sphere! I learn how to make an e-longboard there, and I’ve already posted there for this build. I’m just thinking out loud, especially because I don’t know enough

 

[Ampster]

How many Watts per mile will be a function of how fast you want to go. The Watts per mile goes up very fast with the speed and overall is somewhat related to the weight. You could get 25-50 Watts per mile on the flats at 5-10 mph. I am sure there are many reliable estimates on Endless Sphere. The QS motor you referenced is an 8000 Watt motor. If it could go 50 MPH you would use 160 Watts per mile to go 50 miles. That is a lot of batteries.

When I was messing around with ebikes ten years ago increasing voltage was the easiest way to get speed out of a hub motor. Unless you are going to spend lots of money on a custom frame you will probably use a bike frame so there is always pedal power to get you back home. Once you do the math you will see that lugging around some foldable panels would be a pain. The answer to my question is 15 Watts per sq. ft. for solar energy. That is on a sunny day facing the panels directly at the sun. Do the math and you will see why you don't see anybody doing it. It would take 3 sq ft of panels one hour to get you a mile worth of energy. You could walk faster. The detail the Prius story did not explain is it took a car port size set of solar panels to get that 20 miles of range each day.

 

[Eldan]

Thanks for replying!

Unless you are going to spend lots of money on a custom frame you will probably use a bike frame so there is always pedal power to get you back home.

It’s not a bike, it’s a motorcycle (‘09 ninja 500) so I feel there’s a bit more room to play with.

It would take 3 sq ft of panels one hour to get you a mile worth of energy.

Let’s say that’s accurate, I’m thinking a collapsible 9’ x 4’ array, 3ft^2/mi 36sqft = 13 mi/hr, no? They are really thin I would have to order couple and play with them see if my build idea is feasible.
However for now, I looking to see if it’s technically possible assuming I get to that amount of panels or more.

Prius

From what I read he simply covered the car completely with solar panels

For now, my Main question is not whether it’s worth it or not.. It is simply,
How do I use solar panels to charge a 72v-96v (20-26 cell) battery system ? (if possible)
Hence I came to a solar forum

 

[Ampster]

For now, my Main question is not whether it’s worth it or not.. It is simply,
How do I use solar panels to charge a 72v-96v (20-26 cell) battery system ? (if possible)

The simple answer is you would need enough solar panels to put out about 130 volts if you could find a charge controller that was designed for that voltage.

 

[gnubie]

1kW of flexible panels including the thickness of the connector box is going to be unwieldy just to store on a motorbike and we haven't even started talking about cabling and the charger. As a means of ultimate propulsion the panels would be better used as sails.

 

[Trukinbear]

Unfortunately my drive to town was 22 miles each way.

 

[Trukinbear]

1kW of flexible panels including the thickness of the connector box is going to be unwieldy just to store on a motorbike and we haven't even started talking about cabling and the charger. As a means of ultimate propulsion the panels would be better used as sails.

Sails are a good idea - I had an idea for a hybrid electric sailboat a few years back. Boats often do sit for weeks or months at a time, and cumulatively one could gather a bunch of power this way. My idea was to exchange the ballast for batteries, remove the rigging, and replace the sails with a turbo-sail topped with a retractable vertical axis wind turbine, cover it with a solar cell covered canopy for shade. I love the turbo-sail, that might be the cat's meow all by itself but we'd have it overpowered electrically with enough power (and bow thrusters) to get out of any situation, with something like one of the electric motors from a Nissan Leaf turning a large folding propeller. This would be in essence an easy to handle motor-sailer with computer-aided controls where even a novice could maneuver it like a pro with a game-style joystick and video screens giving an overview view from above, using cameras on the turbo-sail. Just a dream these days as I'm old and poor now, but I can still dream at least.

 

[Craig]

1kW of flexible panels including the thickness of the connector box is going to be unwieldy just to store on a motorbike and we haven't even started talking about cabling and the charger. As a means of ultimate propulsion the panels would be better used as sails.

Why do we have to knock everything? Sorry @gnubie not trying to signal you out but I see this over and over again and it really disappointing to me.

Sometimes the journey is way more interesting than the destination.

Lets forget what is practical and answer his questions reasonably.

 

[Craig]

if he had a panel that produced 93 volts? Could it work without a charge controller since it would never overvolt the battery. Obviously diodes to stop back current to the panels would be needed.

 

[gnubie]

Why do we have to knock everything? Sorry @gnubie not trying to signal you out but I see this over and over again and it really disappointing to me.

Sometimes the journey is way more interesting than the destination.

Lets forget what is practical and answer his questions reasonably.

There are some things that are so obviously a broken idea that there's no point in persuing it. I can talk about a nuclear powered attack penguin at length and ask all sorts of questions as to how to go about building it but it's never going to actually happen. The same goes for this. Just the practicalities of carrying solar panels, of any type or construction, that would do anything useful for charging a battery capable of moving a motorcycle any sort of reasonable distance is completely and utterly impractical. It's been well and truly rebutted in the first few posts in the thread.

It's not even technically possible because the aerodynamics of the bike would be completely and utterly ruined just trying to carry the things in racks on either side of the bike. I'm sure everyone here that has been on two wheels knows all too well how the wind buffets a rider. Now imagine what adding a couple of sq metres of nice wind grabbing panels will do. You'd be in the other lane and under a truck before you knew what happened.

So to address the question in the very title of the thread, no. no it is not possible. As already stated.

 

[Craig]

There are some things that are so obviously a broken idea that there's no point in persuing it. I can talk about a nuclear powered attack penguin at length and ask all sorts of questions as to how to go about building it but it's never going to actually happen. The same goes for this. Just the practicalities of carrying solar panels, of any type or construction, that would do anything useful for charging a battery capable of moving a motorcycle any sort of reasonable distance is completely and utterly impractical. It's been well and truly rebutted in the first few posts in the thread.

It's not even technically possible because the aerodynamics of the bike would be completely and utterly ruined just trying to carry the things in racks on either side of the bike. I'm sure everyone here that has been on two wheels knows all too well how the wind buffets a rider. Now imagine what adding a couple of sq metres of nice wind grabbing panels will do. You'd be in the other lane and under a truck before you knew what happened.

So to address the question in the very title of the thread, no. no it is not possible. As already stated.

Sorry but you are wrong it is completely possible.
Practicality is another matter.

 

[Craig]

To the Original poster I like the idea especially the part with the folding panel system. Controlling the charge could be an issue but I think with some outside the box thinking it could work.

 

[gnubie]

Sorry but you are wrong it is completely possible.
Practicality is another matter.

Fine. How do you propose to store the solar panels on the machine in such a way that it won't end up with the rider under truck?

 

[Craig]

Fine. How do you propose to store the solar panels on the machine in such a way that it won't end up with the rider under truck?

Many ways how about a motorcycle trailer or a side car.

 

[gnubie]

Oh wait, I just thought of the answer to it all. Outrigger wheels. Just build an outrigger frame and weld it to the bike then add two wheels on either side. That will give the lateral stability to allow the panels to be deployed overhead or perhaps on the sides of the outrigger frame and then the motorbike can be charged while riding.

You are right, anything really is possible. If you are dumb enough.