How to Solar Charge an Electric Bicycle

[grindz145]

Another option. Get 3 12v trickle chargers designed for a car. Wire them in series to get ~36v. Then get a spare 36v battery charger for your 36v E-Bike. Open it up and apply the solar 36v out to the rectified side of the 4 diode rectifier on the 240v input side of the charger.

Just curious, are you retarded by chance?

dood! Harsh......

...yammer yammer...

#1, unless you trek deep into the wilderness and still need to charge up....

[jbond]

Another option. Get 3 12v trickle chargers designed for a car. Wire them in series to get ~36v. Then get a spare 36v battery charger for your 36v E-Bike. Open it up and apply the solar 36v out to the rectified side of the 4 diode rectifier on the 240v input side of the charger.

Just curious, are you retarded by chance?

OK. tell me why it won't work. Then go and look at this. viewtopic.php?f=6&t=13091&p=193922&hilit=solarbike#p193922

[heathyoung]

I'd be looking at a decent panel size and voltage - at least 2, 180's or 250's - coupled with a proper MPPT setup and DC:DC converter to get your float voltages right, you would be losing the least amount of power in conversion losses.

[liveforphysics]

AC power comes in, gets rectified to DC, filtered with a cap, then switched at 50-500khz, run through a step down transformer, rectified again, and then sent to a regulation stage (linear or switching), then filtered, and sent to the pack.

Just hook the cells to the battery if you wanted to do it that way. (and either select the right panel voltage, or use a simple $5 HVC circuit to open a relay when they are topped off) But again, cells on the bicycle itself in no way make any sense, likely the most wasteful application you could use the cells for.

Grid-tie at home in a permanent installation. From sunrise to sunset, you can have your cells supplying energy in the most efficient way. You'r cells will always be creating the most useful energy possible, doesn't matter if you're riding, or parked your bike at a bad angle to the sun, or brought your bike inside, and you don't have to waste extra energy and liability dragging around solar cells (which is semi-retarded in it's own right).

[Gordo]

https://www.bullfrogpower.com/home/onfaq1.cfm#ont3

With Bullfrog Power, you continue to draw electricity from the regional electricity grid, or natural gas from the national natural gas pipeline system—just as you always have—and Bullfrog's generators inject renewable electricity or green natural gas onto the respective energy system to match the amount of electricity or natural gas your home or business uses. No special equipment or wiring is required.

So it's like buying carbon credits ... you hand someone money, they promise they'll do something, but you have no way of verifying that they're actually doing what they're doing.

Oh, they have audits through some 3rd party company.. that they picked..


I'll take the panels please.

Are there really enough stupid people on the planet to support this GREEN BS?
+1 on the panels.

[Lock]

Are there really enough stupid people on the planet to support this GREEN BS?
+1 on the panels.

Hehe... didn't realize it was that complicated. I'm just buying electrons from somebuddy elses grid-tied panels, wind gen, etc... or are grid-tied panels also "BS"?
Lock

[John in CR]

Charge controllers are available with almost any desired output voltage (to the battery) and a wide variety of wide range input voltages. While previous posters are correct about overall economic efficiency and grid tie, our bikes are low power enough that solar charging is feasible in some cases. Once I figure out how to DIY some panels for my bike I expect to only rarely need to plug it in to charge. Of course I'm in the tropics and at altitude, so it's just not the same sun. Plus my rides are typically just short blasts with multiple trips per day, so I can park my bike with the panel(s) at good angles to the sun. Paying only 50cents/watt for the solar cells is what puts it in the realm of making sense, especially once I do a trike with a roof or body.

To me light, durable, and cheap panels are the hold back, not the electronics.

[solbike]

If I had enough money to buy a house and then a bit spare then of course the best option would be to have a grid connected system. Second to that, I like the 36-48V panel regulated down to 42.5V and then directly hooked up to the bike battery. Even though I'll never recover the expense of it all (about $350 all up for me direct from factories) I figure that things aren't always about the money and it's just nice to get some system working. This system actually is pretty good in a few respects as well that weren't mentioned earlier. There are no AC/DC conversion losses and in most cases if you can situate it at work then you are actually getting most of the energy out of it. My uni let me set one up there and I travel 9km to work and 9km back and never have to use my mains power. It's not really the saving from mains power (which is less than 5 cents per day) but it's the feeling of riding on solar energy, the convenience of not having to take my bike or battery inside my house at night to charge up again and also just because we can!

This is the 100W direct solar charging setup I put up at my uni (it actually takes a bit longer to charge than mentioned here but in summer in Perth it's constantly pumping out the electrons):
http://www.solarbike.com.au/solar_success.php

Incidentally, for those wishing to maximise things. I've been playing around a little with testing panels that have a different open circuit voltage. These "48V" panels I bought have an output voltage of around 80V, when I regulate/drop this down to 42.5V I seem to be losing a lot of energy as the maximum current I've been able to measure going into my battery is 1.5Amp (though usually it's about .6-1A). This equates to a max of about 64W - so only really about 64% efficient - though I've been getting these panels from only a mid-range factory in China as they are the only ones that'll do me custom things in low volumes so it was probably never the specified 100W in the first place. When testing with 80W panels that have an open circuit voltage of 54V, I can get a very similar charging rate. Meaning to me that the extra voltage is indeed lost. This could be a factor attributed to regulator design but I believe for a really good "direct" solar charging system then it's best to have the panel at a voltage that will give above about 45V all through the day but not too much in excess as this will be potentially wasted.

[dogman]

I agree, the cost of the panels is what makes other ways of spending money to be green a better way to go. For example, change to led light bulbs, get a more efficient fridge, insulate, or more efficient AC or Heater for the house.

But again, if you have other reasons to desire solar energy that make the setup make economic or practical sense, then the tiny bit you use on the bike won't hurt. I'm thinking of course, of places where there is no power, or you'd have to listen to generators running to have some.

Nothing at all wrong with going grid tie, if you are going big. I'd only want to be off grid with a very small size PV setup.

Personally I'm getting tempted to set up an off grid 200W panel. Then run my TV on the lead acid battery bank. Stupidly expensive per KWH, but I get a back up power plug for those too frequent outages without dragging out the generator from the garage. At least the TV will still work during outages, as well as a charger for batteries. It would get me more power daily than I'll ever use on the bike, thus making the claim possible that my ebike fleet is completely carbon neutral. So what if I still plug the bike into the grid, if I took the TV off it? What matters is that I'm using that much less grid power, not that I actually plug the bike into the actual solar panel.

Soon as the house payment is gone, I want to power the whole house 80% solar. With grid tie. About 7 years from now.

Ya posted while I typed my post. Cool setup on the roof of the school. I'm fuzzy on one thing though, does the pole you plug into ever cut the amps when you are charged? or does it just keep feeding 42v at whatever amps the panel is producing at the moment? I thought that kind of trickle charging once charged was bad for lithium, so that is why the chargers either shut off entirely, or in the case of lead acid chargers, cut the amps to near zero.

[stanz]

I agree, the cost of the panels is what makes other ways of spending money to be green a better way to go. For example, change to led light bulbs, get a more efficient fridge, insulate, or more efficient AC or Heater for the house.

In today's dollars a solar panel installation would be a better financial deal than switching to LED bulbs. LEDs are more efficient incertain applications when you look at lumens/watt but at a much higher cost. I can buy a 12 watt CFL at Home Depot for less than $1 in CT due to incentives. A 60W LED replacement at Amazon, cheaper than Home Depot, is $28.20. The LED bulb consumes less power but it will take many years of average use you pay for the $27.20 difference.

Edit: I just took a closer look at the Amazon LED bulb that is a 60W "replacement" ... it only puts out 300 lumens, that's less than a 40W incandescent!

Solar installations get you a 30% tax break from the feds and in some states up to $2 per installed watt back from your government. I have a college buddy that installs solar systems in NY state and due to all the grants/tax breaks the installations are making money in about 2.5 years. That's a great investment.

I'm trying to do a solar installation on my home and at work. Not because I'm a "green" person but because it makes fiscal sense. Power costs aren't coming down, solar is a good hedge against future costs.

Insulation is also a great investment since our local gas company will pay 75% of the cost up to $2,000.

[John in CR]

What I'd really like to do is make a sizable but very light flatbed-like trailer, big enough for a couple of passengers, and set it up to be pulled by a high power ebike. The trailer would contain plenty of batteries, and have a drive motor with very low gearing to assist up big hills. Build my 500W of solar cells into panels that stow in the flatbed during transit, or maybe form an aerodynamic shell.

Zip down to the beach with the bike and trailer. Disconnect the trailer from the bike and install a front wheel with handlebars transforming the trailer into a low speed cargo trike, and free the bike up for fun riding. After loading up the ice chest(s), cruise the trike down to set up with the solar panels doubling as a roof or canopy for shade. The solar panels keep the big battery bank charged for a stereo system and to recharge the bike as needed. A genny made with a weedeater motor and an RC motor would be a great emergency backup power source.

If I build the trailer with pop-up camper type features it can also be sleeping quarters. About the only thing I can think of to add to the capabilities is easily removable wheels and total waterproofing, so the trailer is also an electric catamaran to take out on the water.

[stanz]

These panels should do the trick for you: http://sunelec.com/index.php?main_page= ... ts_id=1246

$130 each, 110W at 110 vmp, minimum purchase of four would give you 440 watts peak.

[vanilla ice]

I like both options #1 and #2. A good starter option is #2 because its cheaper, which is no small deal for some. And if you want backup power anyway, you've already got the battery and inverter costs to deal with. Not much additional equipment is needed in this case.

[John in CR]

These panels should do the trick for you: http://sunelec.com/index.php?main_page= ... ts_id=1246

$130 each, 110W at 110 vmp, minimum purchase of four would give you 440 watts peak.

Way too heavy for my mobile plans, but that's a great price and perfect for a charging station for my bike. I like the high voltage, so maybe I could get away with switching power bricks as my pack charger, and run them directly off the panel output.

I think I can get away with panels of 200W peak for a bike charging station. During dry season just a single 100W panel may do the trick, since 2 changes in panel tilt wouldn't be an inconvenience. eg leave it overnight with a 45° tilt toward the east for the morning, tilt it horizontal after the mid-late morning errands, and then a tilt westward after the 1 o'clock school run. We don't get the year-round hours of sun that Dogman gets in the desert, but the sun is far more potent here so close to the equator and 1km of altitude. Just ask LFP what 9am sun here does to the skin.

[Gordo]

https://www.bullfrogpower.com/home/onfaq1.cfm#ont3

With Bullfrog Power, you continue to draw electricity from the regional electricity grid, or natural gas from the national natural gas pipeline system—just as you always have—and Bullfrog's generators inject renewable electricity or green natural gas onto the respective energy system to match the amount of electricity or natural gas your home or business uses. No special equipment or wiring is required.

So it's like buying carbon credits ... you hand someone money, they promise they'll do something, but you have no way of verifying that they're actually doing what they're doing.

Oh, they have audits through some 3rd party company.. that they picked..


I'll take the panels please.

Nep;
There is no need to verify what they are doing, they are doing nothing useful.
It is actually much worse. For the producer of "Green Power" to be "included" in the program they pay an initial audit fee up to $5000, plus 0.05% of their annual gross sales, plus the annual audit fee. THEY RECEIVE NO REVENUE. The operators of this goofy program are licensed by the government to collect and keep all of the fees from both the producer and the consumer, for keeping track of the transactions. The producer gets to put an EcoLogo sticker on their plant, equipment and correspondence. The receiver of the "Green Power" pays @ $0.11 per KWH instead of @$0.08 per KWH (our local rates) for dirty power generated by natural gas.
So please run out and get yourself certified for manufacturing your green electric bike, pay for the initial audit of your solar panel power production or send a second check of $0.03 per KWH used, to Bullfrog for magically turn the little electrons before they go into your charger. For an additional minimum of $2100 per annum, you may continue to proudly display the Ecologo on your forehead.
I wish this were not true, but I'm very sad to say, that it is. The next step will be a tax on solar power.

I still like the simplicity of a panel on the bike.

[stanz]

I still like the simplicity of a panel on the bike.

Oh, that's easy!

1) Build a bike with a full fairing.

2) Attach flexible solar panel film to the fairing.

Yes, they do make solar panel film with self-adhesive backing.

[dogman]

Going big with solar can depend a lot on the local tax incentives, and the deal you get with the electric company. Todays headline on the front page, 100kw PV installed and running on the cheese factory in NM. Plans to make it 300kw.

Meanwhile, the big news from Texas, dealing with the exact same El Paso Electric company, People who installed PV on their homes got electric bills that were up to 60% HIGER, than before. ????? It turns out they didn't read their contract too good, and texas state law didn't forbid EPE from sticking it to them. Turns out, the power produced does not go into their house directly. It got metered, and sold to EPE for .05 per kwh. Then they could buy the grid power they actually used for .15 per kwh. Hell of a deal eh? Add to that, they turned on stuff and left it on, thinking they had kwh to burn.

Better deal for New Mexico customers. A few years back, EPE had the same contract in place for NM. I read it, and said, no way no grid tie for me now.

[lcyclist]

A couple of years ago, I scored 2 Sharp panels cheap. I recently built a standalone solar shed in backyard. It is a 250W solar array with 4 Walmart group 31 125AH marine batteries for a 6kWh system. AC power is from a 2000W inverter.

Aside from charging my ebike/power tool batteries; I also use it to run power tools in my shop (saw, drills, etc) and use it to power my lawn mower/hedger. This winter, it will power my outdoor Christmas lights.

The shed is great for charging my lipos as it is isolated from the house.

Here is some pictures of my setup.

Solar shed

solar_shed.jpg (110.7 KiB) Viewed 552 times

inside

inside.jpg (86.89 KiB) Viewed 552 times

[liveforphysics]

Icyclist- I love it! Fantastic setup!

[jbond]

AC power comes in, gets rectified to DC, filtered with a cap, then switched at 50-500khz, run through a step down transformer, rectified again, and then sent to a regulation stage (linear or switching), then filtered, and sent to the pack.

Just hook the cells to the battery if you wanted to do it that way. (and either select the right panel voltage, or use a simple $5 HVC circuit to open a relay when they are topped off) But again, cells on the bicycle itself in no way make any sense, likely the most wasteful application you could use the cells for.

I'd agree that putting cells on the bike makes no sense unless you have a very specific need, like a round the world trip or something.

If you have a boring (!), standard 36v or 48v E-Bike with the typical Li-On battery and charger, then I think plumbing direct into a spare charger makes a certain amount of sense. Switch mode power supplies really don't care what input voltage they have as long as it's above the output voltage. And the charger already knows how to charge LiOn batteries and has suitable cut offs and charging strategies. So applying enough solar cell voltage just after the mains rectification stage should work fine. On the link I pointed to, they'd successfully linked 3 12v solar cells to a standard charger. They had a need to put cells on the bike and mounted them on a trailer but of course, the cells could be stationary on the garage. The point I was trying to make was that for a minimal setup you can do away with the intermediate batteries and inverter or the big cost setup of solar into the grid.

Doing the math on the potential input and output WHr means that a minimal setup might take a very long time to charge your battery. However, if you don't use the bike every day, there might be a sweet spot in there where a couple of days of sunshine are enough to charge the battery for one ride. Even then, one charge of the battery is probably only pennies in electricity cost so you'll never recoup the investment, but you do at least have the feel good factor!

[stanz]

Going big with solar can depend a lot on the local tax incentives, and the deal you get with the electric company. Todays headline on the front page, 100kw PV installed and running on the cheese factory in NM. Plans to make it 300kw.

Meanwhile, the big news from Texas, dealing with the exact same El Paso Electric company, People who installed PV on their homes got electric bills that were up to 60% HIGER, than before. ????? It turns out they didn't read their contract too good, and texas state law didn't forbid EPE from sticking it to them. Turns out, the power produced does not go into their house directly. It got metered, and sold to EPE for .05 per kwh. Then they could buy the grid power they actually used for .15 per kwh. Hell of a deal eh? Add to that, they turned on stuff and left it on, thinking they had kwh to burn.

Better deal for New Mexico customers. A few years back, EPE had the same contract in place for NM. I read it, and said, no way no grid tie for me now.

If you buy power from an investor owned power company in Texas you get net metering, unfortunately EPE is not investor owned.

http://solarpowerrocks.com/texas/

[dogman]

That crappy deal with EPE for the texas customers is in the process of being fixed. Once it got on the local TV news, it suddenly looked like a bad idea for EPE to continue, politically. NM state law made that contract illegal here, so they had to improve the deal for NM customers.

What a great deal it was for those El Paso folks for a while though. All you had to do was spend 20k on a solar panel set up, and it added ten cents a kwh to your bill for every watt it put out. Cool! Now that the situation went on the media, EPE looks like the biggest jackasses on earth. Oh,,,,, that's nothing new. Refer to my comments on needing to use my back up generators several times a year, in a place that has ice storms every 30 years...... I could go on ranting forever.

Icylist's solar shed is exactly what I've been thinking of putting up. Just keep hoping to score some panels on the cheap someday. The perfect size for taking a few ebikes, a few power tools, etc off the grid. It doesn't matter what you actually run on the solar power, you are still producing just the right amount to say your bikes are green.

A resident in the condos where I work just put in 2 kw. His next purchase is going to be a plug in prius to replace his current one. So his car will be carbon neutral, and half of his house. Very cool. Nice for him, he's got cash.

[solbike]

If you have a boring (!), standard 36v or 48v E-Bike with the typical Li-On battery and charger, then I think plumbing direct into a spare charger makes a certain amount of sense. Switch mode power supplies really don't care what input voltage they have as long as it's above the output voltage. And the charger already knows how to charge LiOn batteries and has suitable cut offs and charging strategies. So applying enough solar cell voltage just after the mains rectification stage should work fine. On the link I pointed to, they'd successfully linked 3 12v solar cells to a standard charger. They had a need to put cells on the bike and mounted them on a trailer but of course, the cells could be stationary on the garage. The point I was trying to make was that for a minimal setup you can do away with the intermediate batteries and inverter or the big cost setup of solar into the grid.

Yeah, this is a good way for option 3. I thought of this and pulled a charger apart to have a look at it after seeing the youtube clip of someone doing this. I have little electric ability so got someone to make a regulator for me instead of trying it but I think this would be great to use the intelligence of a charger and limit potential bad things happening. I think that there are two levels of protection in any case, one is setting the output voltage to about 42.5 (for a 36V Li battery), when the battery reaches this voltage then no more charge should be able to enter into the battery. The second protection is from the BMS within the battery; hopefully it has intelligence enough to limit overcharge. Once actually, one of the transistors in a basic reg that was made for me blew out and the output voltage went up to the panel's open circuit voltage of 80V. This was plugged straight into the battery and strangely I could not notice any damage to the battery, it charged up just fine and thankfully didn't burst into crazy flames like I saw in one of the videos posted here. I'll try and get an electrician to pull a charger apart for me and show me where to connect the panel voltage and see how that goes. Any takers keen to help out? Send me an address and I'll send a charger out to you and you can fix it for me so I can plug a panel straight into it? jbond perhaps?

[liveforphysics]

Linear regulators eat a bunch of power.

You just want an HVC. I think Gary even sells them for $10usd assembled or something on that order of cheap. Of with 4 resistors and a mosfets you can make your own for $2.

Then you've got the best possible charge efficiency from cells to battery. It also takes up hardly any space, you could have it inline with the wire rather than a separate box.

[HumboldtRc]

Linear regulators eat a bunch of power.

You just want an HVC. I think Gary even sells them for $10usd assembled or something on that order of cheap. Of with 4 resistors and a mosfets you can make your own for $2.

Then you've got the best possible charge efficiency from cells to battery. It also takes up hardly any space, you could have it inline with the wire rather than a separate box.

How would I make a hvc circuit with 4 resistors and a MOSFET ? Any links? Or just a quick explanation... Thanks

Also can you tell me about making server PS's go into a CC mode, like I asked in the PM I sent a few days back...