My solar e-bike adventure: 251 miles

parajared

10 kW
Joined
Apr 16, 2012
Messages
858
Location
Northern Arizona
Parajared rides again!

Clearly confused about notions of what constitutes “fun” and “sanity” I decided it was time for another multi-day cycling camping adventure! Unlike last time where I relied on rogue power outlets all my charging was done by using the sun with my new fangling solar attachment.

I packed a change of clothes, tent, sleeping bag, jacket, inflatable sleeping pad, tools, a few hygiene items and a fully-automatic assault rifle to ward off commies from the campsite (well actually just a little pocket pistol). I figured it was high time to finally waterproof my stuff and ended up using a method I learned from a youtube video to get r’ done.
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Day 1: Despite knowing about the weather forecast of rain I decided to head out anyway just to see what it was like now that I’m waterproofed and all. It turns out that cycling in the rain is every bit as fun as I was expecting it to be, as in, lets never do that again! The cloud cover was blocking the sun too but I managed to find a small sunny spot halfway through my ride. My new sheep friends seemed to like the sun too.

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Ultimately the clouds completely sealed up the sky ending the day after only a few hours at 61 miles. I set camp in the Coleman Lake area of Williams and spend the rest of the day hiking and playing disc golf. The batteries charged up nicely the next morning taking only about 1 ½ hours to get up to a full charge.

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Day 2:
Lots of weird looks from motorists, it’s hard to bike down the road with a 450 watt solar panel strapped to your bike and not draw attention to yourself. I quickly learned that it was quite awful trying to bike down a bumpy road with a floppy solar panel attached to the trike. The stretch of shoulder between Williams and Flagstaff was in terrible condition and on one particularly hard thump the PVC flexed so much that my cargo managed to skid on the ground puncturing a hole in my inflatable sleeping pad.

I had the pleasure of chasing down a lycra clad carbon fiber race bicycler just to watch the look on his befuddled face as I zoomed past; well that was the plan anyway. The top speed on my solar trike is about 22mph and I let her rip. I would catch up to him on the uphills burning through a lot of energy to out-climb him but as soon as he hit the flats he must have been pushing a good 27mph or so. I chased him all the way from Flagstaff to Mormon lake overlook where he turned off (20 miles or so) and never could overtake the rascal. I didn’t catch the young fella’s name but “Demon Rider: the Mormon Lake anomaly” has a nice ring to it.

After a day of battling the dreaded road shoulder of Bellemont and chasing after a road biker like some kind of lunatic (I call dibs on the movie rights) I set up tent at Camp Verde’s Bull Pen Ranch now at 196 miles in or 135 miles for the day.

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Day 3:
I plugged my batteries in ready for the day’s ride. To my dismay the magical smoke, the supernatural essence that makes all electronic equipment work escaped right out the vent holes of my solar charge controller! I jumped and grasped at the air in an effort to catch the mythical substance but alas my charge controller was without it’s life blood. Despite hearing dire warnings against said practice I decided that it was time to see what happens when I just connect the raw solar panel energy directly to the battery and well nothing exiting happened at all. It turns out that the battery voltage floats a little bit above it’s resting voltage, drops the panel voltage down to it’s level, and takes the amperage from the panels just fine. I was nearly fully charged from the prior day’s evening light so the panels were threatening to overcharge my battery (per my cycle computer: cycle analyst) but that was fixed easy enough by unplugging the battery as I finished packing up. I ran the trike hard for the first couple of miles to bring the voltage down a little to avoid overcharge but that probably wasn’t necessary. I ended up liking the results of not having a charge controller so much that I think this may be the way I do things from now on. Here’s a picture of my MacGyver job. I just chopped the wires then twisted them together.
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The last 55 miles were a breeze, the roads were in good condition and although I didn't have anything to measure panel amperage it felt like my solar panels were charging better than ever. I really liked the camp and charge thing a whole heck of a lot better than trying to find power outlets along the way although the panels were large floppy encumbrances making it slightly harder to find a spot to park and lock the thing up, tougher to ride down bumpy roads.
 
...of course you can charge directly from the panels, with better results over using a pwm charge controller because you are now the charge controller Likely you're also the BMS... ( I am)

A MPPT, a good MPPT controller can provide more charge current under most conditions but any controller only protects the battery(s) and most provide all those magical charging routines flooded lead acid batteries require. (and lithium cells don't)
Lithium battery types need none of the magic. Really, to charge a lithium battery only requires a potential higher than the battery's state of charge (and a bit of current) :pancake: . And since you're the controller, you tell the panels to stop charging when you want. -or whatever-
 
Excellent write up Jared. I'm really impressed with the distances you can ride that thing in a day. My personal best is still about 50 miles when I took the back way up Drake Rd/Perkinsville Rd to the Coleman lake area where you camped the first night. My wife drove up and we had a picnic and rode home in the truck.
The impressive thing that you didn't mention is that you gained about 2000 feet in altitude that first day then climbed some more on the way to Flagstaff.
Did you ride the shoulder of I-40 from Ash Fork to Williams?
Do the panels produce enough power to keep up with the draw on level ground so you only have to dip into the battery on hills.
We have been traveling for a couple of years and are currently down near Yarnell. Will be making a grocery trip up your way in the next week or so. I will PM you and see if we can stop by. I really want to see your solar trike.
 
A MPPT, a good MPPT controller can provide more charge current under most conditions but any controller only protects the battery(s) and most provide all those magical charging routines flooded lead acid batteries require. (and lithium cells don't)
I'm still learning the ropes but my hobby battery is rated to take a much greater charge than my panels can give. Most of my research on solar was through the lead acid solar community and from what I have read charging without a charge controller is a huge no-no. I honestly felt like I had a lot hanging over my shoulder when I made the decision but it really paid off in the end.

Did you ride the shoulder of I-40 from Ash Fork to Williams?
Yeah,
I am getting a nasty swing oscillation with the panels due to the floppy nature of PVC; it's either extremely slow going or Mr. Toad's wild ride if I go fast on even something as smooth as Drake overpass. The road wash on those dirt roads is just brutal!

Do the panels produce enough power to keep up with the draw on level ground so you only have to dip into the battery on hills.
In the early morning my PWM controller was showing an amperage yield of about 4-5 amps which I preferred to exceed draining the battery slightly to favor a higher speed of about 15mph. I would hit a magical time from about 10:30 to 2:30 where I was getting 8-10 amps out of the panels and a 15mph average would also slowly get the battery back to full charge. I tended to not want to get fully charged because I wanted to stop and eat lunch and it seemed wasteful to just have the trike sitting there not charging when I could have used that energy for higher speed instead. This would lead me to flirt with 20mph which was draining on the battery at all hours of the day but finagled properly I could make it so I could stop for lunch and get nearly full charged again and run the battery down pretty low around the time that I wanted to stop and set up camp.

I will PM you and see if we can stop by. I really want to see your solar trike
Ok, look forward to seeing you.
 
Nice setup!
 
Nice place to ride too! I've been wanting to ride some of that old 66 in AZ myself.
 
parajared said:
I am getting a nasty swing oscillation with the panels due to the floppy nature of PVC; it's either extremely slow going or Mr. Toad's wild ride if I go fast on even something as smooth as Drake overpass. The road wash on those dirt roads is just brutal!

I had the same problem with my 200W configuration. Annoying but liveable at 14mph, but not fun at ALL at 20+mph.

I finally moved the solar panels to a relatively light trailer and can now use them with my other ebikes too.

The trailer has plenty of room for 400W, and it makes a nice rain-roof for the contents of the trailer. It also simplifies the problem of where to put camping stuff.

If I go to 400W, I will ditch the charge controller completely and replace it with a voltmeter and a switch. Sure does simplify everything although it does offer the opportunity to overcharge if you forget to turn it off.

With 400W, I could ride from 10-4 pretty much without a battery -- pretty sure I would break first.

BTW -- Cool rig -- 450W wow !!
 
So, with a compatible plug, can I SAFELY charge my 52V 11.6 ah Dolphin pack directly from a solar cell and not damage the battery? The solar cell I have now is small, 1'x2', but does it matter?

Thanks for any help you can give to a newby!
 
Stu, solar panels come in many voltage ratings all the way up to several hundred volts. So the answer is no for solar panels in general and yes if you can get a panel with an open circuit voltage (VOC) at or just above the voltage of your battery pack. I suspect the small panel you have is about 17 volts for charging 12V lead acid batteries, in which case it will do nothing for your 52 V battery pack. Keep in mind that the voltage varies during the day and is affected by haze and cloud cover.
If charging directly without a charge controller pay close attention to prevent overcharging.
 
Not correct, individual solar modules are at most close to 40 volts most in the 30's. That is their max power point (open circuit voltage a bit higher), the sweet spot where they produce the most power. Only by daisy chaining them in series can you get to the higher voltages.

Maybe you meant solar ARRAYS, they can and are any voltage desired, individual modules less then 40.
 
So, with a compatible plug, can I SAFELY charge my 52V 11.6 ah Dolphin pack directly from a solar cell and not damage the battery? The solar cell I have now is small, 1'x2', but does it matter?

Thanks for any help you can give to a newby!

I presume yes,
You will need to find out what the voltage of your battery is at a full charge then rig up you panel voltage to be greater than that number (either through serializing or through use of a boost converter). The "C rating" of your battery will dictate how many amps you can pump into your battery without roasting it (I presume you have at least 1C or we could say 1 times the ah rating= 11.6 amps). The solar panel will just keep pumping amperage in, overcharge, and destroy your battery hence the need for a charge controller.

Since you have a 11.6ah 52v battery you have a 603 watt hour battery (11.6x52). Your tiny 1x2 solar cell, lets say it outputs 25 watts just to be generous would take 24 hours of perfect sunlight to charge.

I initially said "presume" because I remember reading somewhere that the solar charge controller regulates the temperature of your panels too, like a keep them from overheating kind of thing but I will need to put more research into that before I know the whole story.
Empirically speaking my panels didn't feel hot or anything after my no-charge controller day.
 
Nice read... Sounds like you had a lot of fun. From the pictures it looks like there was not alot of sun. To fix that issue you should come down south a bit and try that ride in a month or so. Say Phoenix in June. With your nice sun shade it should not be too bad.

Seriously... I envy your ride and ingenuity.

NS
 
I stand corrected because I can't find any referances for the high voltage panels. It has been about six years ago that I saw some deeply discounted on http://www.sunelec.com that were rated above 100VOC. They were huge.
What you say is correct and I should not talk in generalities.
Let's get back on topic and not detract from Jared's cool accomplishment.
 
Nice read... Sounds like you had a lot of fun. From the pictures it looks like there was not alot of sun. To fix that issue you should come down south a bit and try that ride in a month or so. Say Phoenix in June. With your nice sun shade it should not be too bad.

Sounds like fun, I'm a soldier (ARMY veteran), climber (top-roping), skydiver (accelerated free-fall), dirt-biker (XR-600), RCer (DLGS), FPVer (mini-talon), geek and electric biker. We seem to share similar interests and would probably have a fun ride.
 
Stu Summer said:
So, with a compatible plug, can I SAFELY charge my 52V 11.6 ah Dolphin pack directly from a solar cell and not damage the battery? The solar cell I have now is small, 1'x2', but does it matter?

Thanks for any help you can give to a newby!
n00by as in b00by. Wink.
MPPT Solar Panel Battery Regulator Charge Controller with LCD Color Display 24/36/48/60/72V 10A with DC-DC Boost Charge Function

http://www.aliexpress.com/item/MPPT-Solar-Panel-Battery-Regulator-Charge-Controller-with-LCD-Color-Display-24-36-48-60-72V/32653059039.html
 
tomjasz said:
...
MPPT Solar Panel Battery Regulator Charge Controller with LCD Color Display 24/36/48/60/72V 10A with DC-DC Boost Charge Function

http://www.aliexpress.com/item/MPPT-Solar-Panel-Battery-Regulator-Charge-Controller-with-LCD-Color-Display-24-36-48-60-72V/32653059039.html

I bought exactly this device and it works as a programmable DC-DC boost setup (the fan is very noisy, replace it with another one) but this device is not useable for solar charging.

A MPP tracker does not exist, the device has to be started manually AFTER having enough power on the solar side just to start it, you have to program the battery parameters áfter each start (U max, I max) and than the device starts increasing current until it stops at I max or until the voltage of the solar panel collapses. It will wait 5s and start again. It is not able to find a MPP on ist own.
So solar charging is next to impossible, efficient solar charging is completly impossible or I'm an idiot and simply do not know how to "switch" the device from DC boost to solar charging. Maybe you can do this but I do not know how...

Now I ordered an expensive charger from Genasun.
 
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