parajared's solar trike attachment

[parajared]

Outlets? Where we’re going, we don’t need outlets.



Inspired by my last cross country trip, the Sun Trip 2015, but a bit disparaged about the amount of time spent last trip huddled up behind soda machines like a homeless person tapping open outlets for energy I decided to make a solar attachment for my e-trike with hopes of doing my re-charging at the campsite instead.

The rack:
I also gained inspiration from people building PVC patio furniture and decided that if PVC pipe is enough structure to hold someone’s 300lb butt it’s probably plenty for solar panels. Comparing a 6ft stick of aluminum to a 6ft stick of PVC the PVC ended up being 1 ¾ lbs heavier and a little floppier but I chose PVC anyway because of the price of aluminum in my region. I considered building my solar panels tiltable, like a point at the sun while you are riding sorta thing but I also considered the hilarity that would ensue with a nice strong cross-breeze so I ended up building the panels to be completely flat for riding and detachable for pointing at the sun when parked. This ended up being an example of a great idea on paper but trumped by actual experience; in practice it was just easier to tilt the entire trike and prop my helmet under the frame than fuss around with detachment. I added a camping gear rack to the solar rig as well to break away from having to haul a trailer.




The batteries:
I used 12s 10ah of Hobbyking lipo for my setup dropping down from my usual 20ah or my last big trip where I hauled a whopping 30ah. My solar charge controller just sent raw amperage to my batteries without any balancing which lead to two problems:
1) after a long day of riding my sagger packs were about a half a volt lower than my fresh packs. Simply plugging the packs together in parallel every few days fixed this nicely.
2) after a long day of riding my packs were starting to get a little out of balance but I fixed this easy enough with a battery voltage checker with a balance function



The panels:
I serialized four 50watt HQST flexible panels to make a 48 volt 200 watt setup for my 44 volt battery. This got me about 2.9 amps which felt pretty wimpy power-wise, presumably enough for mutant legged man-beasts but not enough for me so I ordered four more panels. Before I installed them I did an experiment. I connected 3-in-series (36 volts) to my 44 volt battery to see what would happen and it turns out its totally fine and yields the exact same energy (2.9 amps) as 4-in-series (48 volts). This is because the panels actually give out 20 volts per panel so the 60 volts I was getting was enough to hit the 50.4 volts needed for a full charge. So now using just six panels (3s 2p 300w) and getting about 5.8 amps of charge I was kicking along at a considerably faster clip, hauling my out-of-shape rear in the ballpark of 50 miles in the morning, a longish lunch break for recharge then another 50 miles in the afternoon. 300 watts is probably more than plenty for most people but still not impressed by this number myself I grabbed those extra two panels in the garage, bought one more and upgraded to 3s 3p for a charge of 9.7amps if the planets were aligned perfectly and the gods were shining down on me, realistically 8-9 amps was about par for the course. On my run today I cleared 37 miles in 2 ½ hours bringing the battery down from 4.2 volts per cell to 4.0 volts per cell (48 volts). My run was ended early due to a rainstorm but my solar rig is starting to really show some potential.




My Solar Adventures

trip 1: 251 miles

 

[Wheazel]

Thats pretty damn cool, how much is the auw? Does it handle wind?

 

[parajared]

As far as wind goes I had the fortune/misfortune of getting to test out my rig in some serious wind. You lose a lot of aero but you don't get yanked off course or anything.

The weight (rack + panels) weighed in at 32lbs when I just had 300 watts attached. I haven't weighed it with the new 450 watt upgrade but I estimate I added another 15lbs or so for a guestimate of about 50lbs. Originally I was just thinking just four panels so the weight penalty of PVC was only a few lbs, but that penalty stacked up on me a bit once I added another 5 panels into the mix. If you have the cash for it aluminum seems the way to go. The HQST's website says the panels weigh 2.8lbs a piece so most of my weight is in the rack itself.

Despite not having the best weighing arrangement I actually lost some AUW!
-lost about 10lbs swapping my 800 watt charger+power supply for a little emergency only 50 watt charger.
-lost 22 lbs and some wheel drag ditching the trailer
-lost about 10lbs swapping my thick rubber electric powered air-mattress for a self-inflating pad
-lost 14lbs switching from 30ah to 10ah of lipo.

Don't go by my heavy solar setup though, Marissa Muller made a 240 watt rig that only weighed 10lbs

 

[dogman dan]

Wow, 9 amps of 48v is enough to cruise at a decent speed indefinitely. Always love to see what you are up to next. Impressive.

 

[icerider]

Nice work. And being in AZ, I'll bet the shade is a welcome side benefit.

 

[AF7JA]

Posting on this because I want to be able to find this thread in the future.

Adding Solar to my e-trike is next years winter project. I didn't see what you are using for a controller.

To be clear, you have 9 panels, three sets in series, then wired together parallel. Is that correct?

 

[parajared]

Yeah nine 50 watt panels (3s 3p). I serialized first then paralleled but as far as I know it doesn't make any difference one way or another. Ultimately if I had the knowledge I had now and I could do all over again I would have gone the larger battery smaller panel route and gone with three HQST 100 watt panels simply doing 3-in-series. The thing is that if you only spend 6 to 8 hours in the saddle you have plenty of time to put energy into a battery when you are parked. I speculate that a 20ah 300 watt setup will get you similar stats to a 450 watt 10ah setup but still enough energy to get you down the road with little to no drain on the battery.

I didn't see what you are using for a controller

I shutter to give the controller I used any publicity at all but I burnt through both the 10amp and 30amp variants of the Wincong controller. I would highly suggest using a different brand if you decide to use a charge controller. Keeping an eye on the voltage displayed on your cycle analyst and simply unplugging your batteries when you hit your charge voltage seems to work great with the stipulation that your stops at the store, lunch breaks, and camping means having to check on the batteries from time to time. Perhaps there is a way to rig up a voltage activated switch to turn things off but it seems easy enough to just unplug if you know you are going to be away from the bike for a while.

Presumably if you are going down a hill or cycling with a buddy pacing slow enough that you are expending less energy than you are collecting you would run into a overcharge problem as well. I believe that the solution to this potential problem (assuming you are not using a controller) is to have a switch within arms reach that would "turn off" the flow of energy from the panels.

 

[craneplaneguy]

As far as wind goes I had the fortune/misfortune of getting to test out my rig in some serious wind. You lose a lot of aero but you don't get yanked off course or anything.

The weight (rack + panels) weighed in at 32lbs when I just had 300 watts attached. I haven't weighed it with the new 450 watt upgrade but I estimate I added another 15lbs or so for a guestimate of about 50lbs. Originally I was just thinking just four panels so the weight penalty of PVC was only a few lbs, but that penalty stacked up on me a bit once I added another 5 panels into the mix. If you have the cash for it aluminum seems the way to go. The HQST's website says the panels weigh 2.8lbs a piece so most of my weight is in the rack itself.

Despite not having the best weighing arrangement I actually lost some AUW!
-lost about 10lbs swapping my 800 watt charger+power supply for a little emergency only 50 watt charger.
-lost 22 lbs and some wheel drag ditching the trailer
-lost about 10lbs swapping my thick rubber electric powered air-mattress for a self-inflating pad
-lost 14lbs switching from 30ah to 10ah of lipo.

Don't go by my heavy solar setup though, Marissa Muller made a 240 watt rig that only weighed 10lbs

A 240 watt solar panel weighs about 40 lbs on average, unless she used something from NASA.

 

[parajared]

A 240 watt solar panel weighs about 40 lbs on average, unless she used something from NASA.

You haven't been keeping up with new solar technologies. The cheap widely commercially available stuff I used would weigh about 12 lbs without the rack to make 240 watts and likely the stuff Marissa used is the much more expensive ultra thin solar film. However the really cool solar panels are the ones that the solar race teams are using. Instead of just exploiting the visible light spectrum they also collect energy from the infrared and ultraviolet spectrum as well.

https://en.wikipedia.org/wiki/Solar_car_racing

 

[craneplaneguy]

My decades of solar experience, using, selling, and installing, is all tempered glass rigid frame types. My last batch cost me about .75 a watt inc shipping. Name brand, last forever, grid tied. I'll get educated n the lightweight piortable ones

 

[craneplaneguy]

OK, near as I can tell the reason these light weight panels have somewhat slipped below my radar, is that they are more then double (close to triple with the SunPower ones that Marissa used) the cost per watt then what I use for grid tie and off grid jobs, conventional tempered glass, heavy framed modules. It's a little confusing when the weight quoted is totally not counting whatever structure is needed to actually mount them properly, not confusing I guess but misleading a bit.

I find myself in the ironic position of being very experienced in most things solar, having lived and worked with it for the last 30 years, selling it, being totally (more then 100%) solar powered at my home AND my crane yard in town, installing large systems, etc. , while at the same time finding it hard to fathom hauling any significant array around to recharge on the road being practical! But those SunPower panels are pretty darn cool, though like I said real expensive. For now I will continue to 100% recharge my three different bikes using my grid tied conventional solar panels, but will keep a closer eye on the newer light weight modules, at the same time the next large batch I buy for resale will be what I am used to using. They are still the best bang for the long term buck, unless space and weight is a major factor. I'll post a picture in a day or so of a very large solar trailer I could use to run all three of my bikes, at once!

 

[AF7JA]

Well, I went ahead and ordered some solar stuff (two 140W panels and a charge controller). These will be put on the trike; as such I wanted to keep the width under control. I expect that for long trips I will end up pulling a trailer.

Because I work in Kansas and live in Utah, my long term build needs to have ∞ range. However, this build is a few years away. I will already be away for the summer when the panels arrive; so it will be next years project.

 

[parajared]

Very cool! Panels make a very nice sun/rain shield. I'm curious to see how you build your rack. I like the way Bernard Cauquil did his too.

 

[parajared]

For now I will continue to 100% recharge my three different bikes using my grid tied conventional solar panels, but will keep a closer eye on the newer light weight modules, at the same time the next large batch I buy for resale will be what I am used to using.

I used HQST panels for $1.40 per watt so a better deal than Marissa's but still not something you would want on a house for that price. Just using a battery (no solar) is actually quite viable for most stuff. I can knock out 40 miles without too much sweat off just my 20ah battery pack and I am considering touring some of America's scenic bikeways just doing little 40-50 mile trips this way using my car as the charging station'

As far as cost savings solar re-charge vs house recharge we are talking mere pennies here; the bulk of the cost, at least for me as a hobby lipo user is in the duty cycles. My last pack lasted about 400 cycles (or 3 seasons) and cost me about $200 after shipping so about 50 cents per duty cycle. APS (my energy provider) charges me 9 cents per kilowatt hour so my 880 watt hour pack in theory would cost less than 9 cents to charge using "the grid."

Home solar is still pretty awesome though and I really like the idea from an independence standpoint. Also unlike the "golden years" where you could invest your money and make 4-5% interest easy, and 10-12% if you are willing to take a bit of risk now a days I struggle to make even 3% on an investment these days. Solar panels are pretty killer from an investment standpoint in that you instantly make a good 5% ROI (return on investment) right from the get-go.

 

[Warren]

Bernard Cauquil is running 80 cells, like two of these panels, on his bike.

http://store.evtv.me/proddetail.php?prod=120wsolarpanel

"GET EM WHILE YOU CAN. These are the last available. The U.S. has imposed a 250% IMPORT TARIFF on these panels. These are the last we have in stock and when they are gone, we won't be buying more. YOU CAN SAVE AMERICAN JOBS simply by making things four times more expensive."

In this shot anyway.

http://ezeebike.com/wp-content/uploads/2015/01/unnamed.jpg

In this shot he has a truly massive array!

https://lh3.googleusercontent.com/-HG1CliBHSwA/Vcr6STdbmcI/AAAAAAAALjU/Ou9np1biQ_c/w3840-h2160/DSC_0367.JPG

132 cells is 396 watts.

http://store.evtv.me/proddetail.php?prod=sunpower

 

[craneplaneguy]

Here's my pathetic attempt at a solar powered E bike. Though at 2280 watts I have plenty of power, counting the dual axle trailer, the weight came in at well over 1 ton. A serious upgrade to the Trail Viper's mechanical disc brakes may be in order This is actually an array for a customer ready for delivery, it will be pole mounted similar to the array in the other picture.


I have had more success with this grid tied 1920 watt system, it's at my crane yard in town and is actually an array I had installed at home (along with more PV, hydro, and wind systems, all grid tied) until I realized my KWH surplus with my utility was growing annually, and I could "afford" to transplant this one array down to the crane yard. It will now totally offset my electrical heating loads in the 3 months I need heat in the crane shed (radiant floor heat, electric boiler, temp at 50 degrees). One great thing about grid tie, is the that the utility, at no extra charge, provides you with a very accurate written record of how much power you have consumed (they call it a bill, I call it an earning statement), thus by going back over old records, I can very accurately predict the result. I should actually be able to bump the temps in the crane shed up to 55 maybe, anything over 45 is pure luxury for winter time storage of heavy equipment. My non solar assisted competition in the local biz keep their rigs outside and just plug in the engines (and pay for it), I have the entire rig rig, for freeView attachment 1

Anyway.....the light weight flexible panels more applicable to ebike use are pretty cool, and the pricing not as bad as I thought. Personally, I would lead toward a trailer configuration, by the time you enough on a 2 wheeled bike you are forced to have a pretty ungainly apparatus overhead. Marissa had it pretty well figured out it seems.

 

[AF7JA]

My panels and charge controller arrived yesterday. However, I fly out for the summer on Monday; so the project is on hold for a few months.

Hopefully, during that time, more pictures of how the panels have been attached to trikes will be posted. It is just a matter of getting more, and better, ideas for how to go about it

 

[craneplaneguy]

parajared: you got me up to speed on these lighter/thinner/flexible panels, to the point that I am eyeballing the roof above the cockpit of the plane, (thanks, I guess!) I don't want to bogart your thread so started another concerning my particular questions and would appreciate your input if you have any. "SOLAR CONTROLLER FOR 52 V. BATTERY AND SINGLE PV PANEL."

 

[parajared]

SOLAR CONTROLLER FOR 52 V. BATTERY

I'm no expert in what's good and what isn't but the controllers I have tried so far are total crap. I would rather not give the controller I was using any publicity at all but I recommend you steer clear of Wincong controllers. I am thinking about building my own but my knowledge of electronics is limited. I was thinking of using an analog volt meter with a needle and rig it so that when the needle gets high enough it would touch another wire and complete the circuit to a 5v relay switch. As soon as the power from the panels are shut off however the voltage will of course drop and the switch will try to turn on and off again repeatedly. I believe I would wire some capacitors into the circuit so that there would be maybe a 30 second delay between the on and off as the capacitors would continue to discharge that 5 volts for a little while until they are completely discharged but I bet someone who actually knows what they are doing would know of a much better solution.

 

[parajared]

Also I would use a 5v relay because cell phones use 5 volts to charge and that 5v would be useful to tap into so that I could re-charge on the road and use my phone as a GPS unit.

 

[cycleops612]

dunno, just putting a thought out there, but if an ebike controller has a provision for regen input, isnt that the basics of the circuitry needed to input the pv output into the native managed circuit of the controller?

Regen braking is a dubious benefit anyhoo?

I gather regen input is not usually protected from overcharging the battery, but that can be solved variously.

 

[parajared]

My Lyen controller does not have an overcharge protection feature but perhaps there is a controller out there that does.

As far as usefulness of regen, regen is accompanied by the problem where if you repeatedly brake with it you get a problem where it wiggles the shaft or something and loosens the nuts. Easy fix is to just tighten the nuts from time to time but for "regular" riding there is very little benefit as the majority of your stops involve rolling to a stop with little to no assistance from either regenerative or physical braking. This isn't to say that regen isn't useful however, say for instance when you have a 50 lb solar panel or a bunch of camping gear strapped to your trike your braking authority you have goes way down. The fact that you regenerate power just happens to be a nice little side effect of the much more useful feature of having an increase in stopping power.

99% of the time you want regen off, but it's great to have a switch that can turn on regen for those mondo hairball downhills assuming you have the torque arms to handle the stress.

 

[cycleops612]

?

my, perhaps ignorant, point was, i get the impression you also have a controller for the PVs.

why not simply use the regen input that often pre-exists on ebike controllers, to feed in the PVs current. In a normal regen scenario, this current would recharge the battery via the ebike controller. I dunno in the new scenario of running the motor while receiving regen input. that may confuse the software.

but i do know, i can have my charger connected and run my ebike, from tests.

another way of putting the problem i mentioned, is warnings against using regen with a fully charged battery. there is no protection built in against overcharging the battery. it doesnt sound hard to fix.

 

[amberwolf]

The "regen input" is the same as the motor itself--the phase wires from the controller to the motor.

So you can't use the motor controller for inputting from some other voltage source unless you first disconnect it from the motor, if for no other reason than that the motor windings will appear as a direct short to the panel.

Plus, when the controller is running the motor, it would be outputting a voltage across the panel, trying to force current thru it (whether there is sun on it or not).

To use the controller as a "regen input" taking the voltage from the panels back to the battery, you'd need to use one not connected to a motor, and with the ebrake input turned on. But you probably can't just wire the brake input on, it probably has to be turned on after powering on the controller, or the controller will probably fault. You may also have to either keep an inactive throttle wired to it's throttle input, or wire up a voltage divider to the throttle input to put a throttle-off voltage level (whatever that controller needs), or it may fault without any throttle input.


Additionally, if you use a 3-phase controller, if you only put a panel across two phases, I'm not sure how the controller will handle that. Might fault and stop converting. You might have to use a brushed-type controller instead.

 

[cycleops612]

The "regen input" is the same as the motor itself--the phase wires from the controller to the motor.

So you can't use the motor controller for inputting from some other voltage source unless you first disconnect it from the motor, if for no other reason than that the motor windings will appear as a direct short to the panel.

Plus, when the controller is running the motor, it would be outputting a voltage across the panel, trying to force current thru it (whether there is sun on it or not).

To use the controller as a "regen input" taking the voltage from the panels back to the battery, you'd need to use one not connected to a motor, and with the ebrake input turned on. But you probably can't just wire the brake input on, it probably has to be turned on after powering on the controller, or the controller will probably fault. You may also have to either keep an inactive throttle wired to it's throttle input, or wire up a voltage divider to the throttle input to put a throttle-off voltage level (whatever that controller needs), or it may fault without any throttle input.


Additionally, if you use a 3-phase controller, if you only put a panel across two phases, I'm not sure how the controller will handle that. Might fault and stop converting. You might have to use a brushed-type controller instead.

I may have understood your answer, but so much was garbled by the strange notion that the regen would actually be used for regen. Why? its ~useless except as a brake most agree. Of course not. It is simply an ebike controller input labelled "regen", which could conceivably be fed current SOLELY from the PVs. I dont know the logic after that.

my limited understanding in simple terms is, brake on=make motor a generator & possibly, prepare to receive current via the regen input wire. If this signal goes via the unconnected regen wire loom to the motor, then the motor is unaffected by the brake on condition, as it never gets the signal.

I dont know. It was just an idea. thanks for the answer. sorry most was lost on me as i wasnt sure what context it related to - connected or disconnected?

I dont doubt there may be a fatal flaw in the idea. But if it worked, it sounds neater than 2 controllers.