Solar charging

Tim

Esteemed Pedelecer
Nov 1, 2006
770
78
London
Hello, first post to the list! Great to see something like this get off the ground.

Has anyone had experience in charging their battery using solar panels? Is it viable at these latitudes throughout the year? Would I have to use an inverter to turn the output into a usable supply? Is anybody running their electric bike entirely 'off the grid' using solar or other renewable supplies?

Tim
 

flecc

Member
Oct 25, 2006
52,760
30,348
Yes Tim, the A to B magazine editors run their Lafree from solar and have published articles on it. We have another thread running on this and some of the answers you seek are in the some of the answers on that thread. Here's the link to it:

http://www.pedelecs.co.uk/forum/showthread.php?t=17
 
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Lazybee45

Finding my (electric) wheels
Nov 3, 2006
5
0
70
Iowa, USA
I am runnning a pair of 15v solar panels (10 watt so they are about .6-.7 amp charge rate) They work better than people told me they would, but not enough to get full time power from teh battery. I use them to extend my range and as a charging station while stopped. these are pretty simple units and they are wired basically direct in series to the battery pack through a plug like the standard charger uses. they charge even in pretty diffused light. grey overcast days too. I don't know if you could do an indefinite length ride using ONLY solar panels, but they help some and while youare riding, they are ALWAYS trickling power in. same when you stop. I have ridden my bike to work and left it parked out in the sun and had the batteries fully charged when I returned to the bike! So do they work? yes, are they perfect? no.

mark
 

rsscott

Administrator
Staff member
Aug 17, 2006
1,398
193
Hi Lazybee45, do you have any photographs you could show us ? It sounds like a very interesting setup.

I am runnning a pair of 15v solar panels (10 watt so they are about .6-.7 amp charge rate) They work better than people told me they would, but not enough to get full time power from teh battery. I use them to extend my range and as a charging station while stopped. these are pretty simple units and they are wired basically direct in series to the battery pack through a plug like the standard charger uses. they charge even in pretty diffused light. grey overcast days too. I don't know if you could do an indefinite length ride using ONLY solar panels, but they help some and while youare riding, they are ALWAYS trickling power in. same when you stop. I have ridden my bike to work and left it parked out in the sun and had the batteries fully charged when I returned to the bike! So do they work? yes, are they perfect? no.

mark
 

WayneC

Finding my (electric) wheels
Jul 4, 2007
7
0
Starkville, Mississippi USA
TuneCharger Solar Cell Charging Circuit

For anyone who wants to try using a solar cell with their electric bike, a French inventor has come up with a neat "TuneCharger" circuit that will allow virtually any size photovoltaic solar cell charge almost any type of rechargeable batteries: from lead-acid through NiCd/NiMH and on to Lithium-ion. Basically what the circuit does is save up the energy from the solar panel and then send it in an electric pulse when the correct voltage and current for your particular battery is reached.

I have just received two TuneCharger kits that include the printed circuit board and all parts to solder onto the PCB. I believe the inventor was phasing these kits out and may have only contructed circuits for sale now.

For more information, you can go to chargeur de batterie par impulsions tolérant aux fluctuations de la source - Accueil -. There is also a TuneCharger forum on Yahoo!Groups you can find by going to Yahoo! Groups - Join or create groups, clubs, forums & communities and searching on "TuneCharger." If you join this group you can read about lots of applications that people around the world are using the TuneCharger circuit with.

When I'm able to assemble at least one circuit, I'll be testing it for various applications and will report back here what I find. I don't have an electric bike at this time, but I may have one by the time or soon after I get a TuneCharger put together.

Wayne
 

flecc

Member
Oct 25, 2006
52,760
30,348
Thanks Wayne, those results will be very interesting. I'm not sure how some lithium battery electronics will react to a pulse charge fed to them, but for all the other types it's a good charge method.
.
 

coops

Esteemed Pedelecer
Jan 18, 2007
1,225
1
Manchester U.K.
What happened Ian? I wondered how you got on on holiday? Has something gone seriously wrong, or not enough sun & too much water? :rolleyes: does your solar charger thread need updating now then?

Hydro seems a good source for energy, but more messy to implement & requires a source of flowing water, no?

Stuart.
 

WayneC

Finding my (electric) wheels
Jul 4, 2007
7
0
Starkville, Mississippi USA
Thanks Wayne, those results will be very interesting. I'm not sure how some lithium battery electronics will react to a pulse charge fed to them, but for all the other types it's a good charge method.
.

Yes, I can see a lot of experimentation ahead to see just what will work well with the circuit. I have a big advantage in being involved in the design and installation of a sophisticated automated observatory that is going to have multiple banks of rechargeable batteries of all types. When complete, the observatory will be fully accessible by anyone on the Internet who wants to book observing time there. Instrument results and any astrophotography camera exposures a user runs will be transmitted back to him/her via the Internet. In addition to a large bank of lead-acid batteries with the capacity to run the observatory for an entire night's observing run if there is a power failure, there will be other auxiliary instruments running on rechargeable batteries as well, such as the weather station that gives the observatory the signal that it has started raining and that it should close up shop until better weather. I will therefore be playing around with multiple battery types using the TuneCharger circuit and solar cells. The weather station in particular will have several power sources, including solar panels, since it is imperative that it have no down time whatsoever. One drenching of all the telescope's instruments would probably result in a massive repair bill. The weather station will be supplemented with a cloud detector with similar backup power.

There are TuneCharger users getting results using it with lithium-ion batteries, but I don't recall at the moment if they did any additional modifications to the circuit.

Sorry to go off-topic! Back to electric bikes: since I am about 400 miles from the nearest electric bike dealer, I have been depending a lot on all the great postings on the Pedelec forums to help me narrow down which electric bikes would be best for me to try. I'm lucky that my wife is a secondary-school biology/physics teacher, and she is very big on sustainability and green power. She's 100% behind my project to get an electric bike for less impact on the environment than my current sole means of transportation--a large V8 pickup truck that almost gets gallons-per-mile instead of miles-per-gallon. :) There are probably a quite a few husbands whose convincing the wife of the wisdom of an electric bike is the largest hurdle to overcome in their purchase! :D

After getting so much invaluable help here from everyone being so generous with sharing their hard-won electric bike experiences, I hope I'll be able to give back with at least a few postings!

Best regards,
Wayne
 

Ian

Esteemed Pedelecer
Apr 1, 2007
1,333
0
Leicester LE4, UK.
What happened Ian? I wondered how you got on on holiday? Has something gone seriously wrong, or not enough sun & too much water? :rolleyes: does your solar charger thread need updating now then?

Hydro seems a good source for energy, but more messy to implement & requires a source of flowing water, no?

Stuart.
Something did go seriously wrong Stuart, but only with the weather. As very little sunshine had been forecast I chose a caravan site with mains electricity and as a result was still able to get some decent rides in, I didn't get a tan though. As for updating the other thread, I'll wait 'til theres some positive news, after all to say that solar panels don't work in the rain is a bit pointless;) . I heard today that the forecasters are saying summer will start on the 15th July:rolleyes:
 

coops

Esteemed Pedelecer
Jan 18, 2007
1,225
1
Manchester U.K.
Shame Ian, but at least you had it working before you left, and once someone makes a hydroelectric charger we'll be virtually covered for our climate :D (wind shouldn't be a problem... if there's no flowing water :)).

Stuart.
 

WayneC

Finding my (electric) wheels
Jul 4, 2007
7
0
Starkville, Mississippi USA
More on Solar Cells and TuneCharger Circuit

I've finally managed to find the time to solder together and test one TuneCharger circuit. After my preliminary tests, I'm very hopeful that the TuneCharger will be useful for electric bicycle applications.

Since my last posting on the forum, I've finally taken the plunge with my first electric bike purchase and should have an eZee Liv arriving in about three weeks.

I'll probably be starting my test of the TuneCharger for bicycle rechargeable battery usage by seeing if I can use it with a small solar panel to keep the batteries charged in an LED headlight for the Liv. (The Liv comes with a dynamo-powered headlight, but tossing it will probably be one of the first things I do when I unpack the Liv. It seems a little strange to me to use an electric bicycle's main battery to propel the bike and then turn right around to use the headlight dynamo on the front wheel to go back in the other direction in providing current for the headlight. :) )

I have a variety of solar cell arrays to experiment with, so I'll be testing to see just what minimum combination of TuneCharger + solar cell array will be adequate to keep the light's batteries sufficiently charged.

Several experimenters are trying the TuneCharger with lithium batteries, but it looks like it's probably safest at this point to stick to using the circuit to recharge only lead-acid, NiCad, and NiMH batteries. The TuneCharger has worked successfully in limited tests of charging lithium batteries, but with the very real danger of fire if conditions aren't carefully controlled and monitored, it's probably wise to stay away from charging lithium batteries at this time.

The set of lights I've just ordered today for the Liv will undoubtably arrive long before the bicycle, and I'll go ahead and experiment with solar cell charging the headlight right away.

Therefore, I should have at least some preliminary TuneCharger results to post here in a week or so. And as soon as I have the Liv in hand, I will give it an extensive workout, followed by my evaluation of the Liv here in the Pedelec review section.

Wayne


For anyone who wants to try using a solar cell with their electric bike, a French inventor has come up with a neat "TuneCharger" circuit that will allow virtually any size photovoltaic solar cell charge almost any type of rechargeable batteries: from lead-acid through NiCd/NiMH and on to Lithium-ion. Basically what the circuit does is save up the energy from the solar panel and then send it in an electric pulse when the correct voltage and current for your particular battery is reached.

I have just received two TuneCharger kits that include the printed circuit board and all parts to solder onto the PCB. I believe the inventor was phasing these kits out and may have only contructed circuits for sale now.

For more information, you can go to chargeur de batterie par impulsions tolérant aux fluctuations de la source - Accueil -. There is also a TuneCharger forum on Yahoo!Groups you can find by going to Yahoo! Groups - Join or create groups, clubs, forums & communities and searching on "TuneCharger." If you join this group you can read about lots of applications that people around the world are using the TuneCharger circuit with.

When I'm able to assemble at least one circuit, I'll be testing it for various applications and will report back here what I find. I don't have an electric bike at this time, but I may have one by the time or soon after I get a TuneCharger put together.

Wayne
 

Ian

Esteemed Pedelecer
Apr 1, 2007
1,333
0
Leicester LE4, UK.
It's good news that you have a bike on the way Wayne. I'm sure your solar charging will be more succsessful than mine, here in the UK the key ingredient has been in very short supply for a number of weeks now.
 

WayneC

Finding my (electric) wheels
Jul 4, 2007
7
0
Starkville, Mississippi USA
It's good news that you have a bike on the way Wayne. I'm sure your solar charging will be more succsessful than mine, here in the UK the key ingredient has been in very short supply for a number of weeks now.

Oh, well... the Liv was supposed to have gotten to the U.S. a week ago and have started on its way to me by Friday, but it appears that there has been a delay somewhere along the line. At least my credit card hasn't been charged yet, and I'm pretty sure I'll see that just as soon as the bike is on its way. :) I actually appreciate the dealer not prematurely charging my card; there are way too many Internet sites that charge your card immediately and then take their own sweet time shipping the merchandise.

Weather here in Mississippi (Southeastern U.S.) has actually been almost ideal for solar power this summer: hot and dry. Unfortunately, this has also meant that just about all the crops--mostly soybeans, cotton, and corn--have been burned to a crisp. September and October are usually our clearest months, with the most comfortable temperature and humidity, so as long as the Liv gets here sometime in August I should have at least a couple of months of good testing weather.

(One of my all-time favorite jokes is about the fellow who is talking to an old farmer, and he asks the farmer what he would do if he won a million dollars in the lottery. The old farmer strokes his chin and says, "Well, I guess I'd just keep on farming 'til it was all used up!" Sadly, there is a little too much truth in this joke!)

Dry weather here almost invariably means someone else is getting really hit hard by rain and thunderstorms, and in this case it has been Louisiana and Texas. The "Bermuda High" sitting on top of us just will not let anything but the strongest cold fronts through.

I intend to take the Liv with me on my next trip down to the Mississippi Gulf Coast for at least one more autumn volunteer stint helping out Hurricane Katrina rebuilding efforts. It should really be the ideal way to get around down there, since there are still (after almost two years) quite a few roads and streets that are barely passable.

Before the Liv arrives, I might be able use my one completed TuneCharger circuit to make a few tests with charging various batteries with my small solar cells. If so, I'll report my results here as soon as I see what's happening...

Wayne
 

flecc

Member
Oct 25, 2006
52,760
30,348
It seems a little strange to me to use an electric bicycle's main battery to propel the bike and then turn right around to use the headlight dynamo on the front wheel to go back in the other direction in providing current for the headlight. :) )

Wayne
The argument for doing this Wayne is that if the battery runs out, the bulb headlight light isn't affected if there's a dynamo supplying it.

On eZee's bikes with LED lighting which we have here, they are powered from the main battery since when the battery runs out to the controller cut off level, the LEDs can still run for many hours off the remaining battery charge given their tiny requirements.

So there is some logic in it, though as you say, using electrical power to generate electrical power does seem odd!
.
 

WayneC

Finding my (electric) wheels
Jul 4, 2007
7
0
Starkville, Mississippi USA
The argument for doing this Wayne is that if the battery runs out, the bulb headlight light isn't affected if there's a dynamo supplying it.

On eZee's bikes with LED lighting which we have here, they are powered from the main battery since when the battery runs out to the controller cut off level, the LEDs can still run for many hours off the remaining battery charge given their tiny requirements.

So there is some logic in it, though as you say, using electrical power to generate electrical power does seem odd!
.
Yeah, that makes sense if the headlamp and taillight are (as is certain to be with a low-end bike) incandescent instead of LED. I am such a believer in LED lights that I have replaced all the brake and turn signal lights on my pickup with LED lamps. They are expensive and usually require replacement of the turn signal controller box as well, but it's nice knowing that the bulbs will never burn out. Also, if I get stuck by the side of the road but have a fully-charged battery, the hazard flashers will blink essentially forever before the battery runs down.

If I switch over to an LED headlight and LED taillight, I should have a small-enough draw on the main battery to run the whole lighting system off it. Since I intend to do a good bit of experimentation, I'll probably set up a power bus in a weather-proof box with switches to allow accessories to run on their own internal batteries or get their current from the main battery. I have an ammeter laying around here somewhere that can be enlisted for the project. It should be interesting to watch what current I'm drawing moment-by-moment.

I just got word that my Liv has indeed arrived in the U.S., and estimated shipment is Thursday, August 2! By this time next week there's a good chance that I'll actually have an honest-to-goodness Liv in hand, ready to start testing. That will actually be almost the perfect time for me to do some experimenting, since Mississippi State University will be out of session that same day and is not back for the fall semester until August 20. I usually have almost a holiday during that whole period, with almost no service calls (or phone calls, period, many times).

My $300 box of accessories for the Liv (LED headlight, LED taillight, emergency bike tools, etc.) arrives today, so I'll be ready to go when the bike arrives.

At the very least, I'll be connecting all the accessories' batteries to the TuneCharger + solar cell, and continuing on to seeing eventually if I can come up with a cheap, easy way to do some charging of the Liv's main lithium battery via the solar cell.

Since there are no reviews of the eZee Liv posted on the forum yet, I'll try my best to get one together and uploaded as soon as I've put the Liv through its paces. Although MSU will be out, the MSU Bicycling Club has some activities while the university is out, and there is "Little Sturgis" the last week of August. This is a micro-version of the famous Sturgis Motorcycle Rally which starts up this coming weekend (The 67th Anniversary Sturgis Rally 2007. Schedules, Lodging, Merchandise, 35,000+ Sturgis Rally pictures and more....). Since our Sturgis (Mississippi) Rally just happens to be only about eight miles from the tiny community we live in, it will be an easy trip there on the Liv. I'll be dwarfed by pretty much everything else at the Little Sturgis Rally, but I might get a second glance from some motorcycle enthusiasts. Considering that people will be coming from up to a thousand miles away for the Little Sturgis Rally, it's the least I can do to pedal down the highway to check out the festivities!
:) Here's the URL for our Little Sturgis Rally: Sturgis South Motorcycle Rally.

Things really couldn't have worked out better with the timing of the shipment of my Liv, with me having huge slabs of time off to test out the Liv pretty thoroughly.

Stay tuned!

Wayne
 

flecc

Member
Oct 25, 2006
52,760
30,348
Thanks Wayne, look forward to your reports and the review of the Liv in due course. I rode one briefly for the first time just recently.

Far from getting just a glance, you may become the centre of attention at the rally, since you might be the one who's most different!

Hope you get your bike without further delay and can get down to some riding.
.
 

WayneC

Finding my (electric) wheels
Jul 4, 2007
7
0
Starkville, Mississippi USA
The argument for doing this Wayne is that if the battery runs out, the bulb headlight light isn't affected if there's a dynamo supplying it.

Yes, it makes good sense if you're an electric bike manufacturer and have to go with something to send along with virtually every electric bike you sell. A dynamo-supplied lighting system makes the most sense to ensure your customers don't end up down a dark country road with plenty of running power but no headlight whatsoever. (It's also nice for your profit margin as well, since I have yet to see a dynamo light system that isn't made of the cheapest materials and that gives more than a feeble little light beam, even with that wheel rotating at a pretty good clip.)



On eZee's bikes with LED lighting which we have here, they are powered from the main battery since when the battery runs out to the controller cut off level, the LEDs can still run for many hours off the remaining battery charge given their tiny requirements.

So there is some logic in it, though as you say, using electrical power to generate electrical power does seem odd!
.
Yes, that is mainly what I was saying: it just seems to be one of those things that rings a little strange when you first hear it. :)

Good news: almost as soon as I entered my last posting, I got an email saying that my Liv is actually already on its way, two days ahead of schedule. It is now scheduled to arrive next Monday. As I said in that posting, this will be almost the perfect time for the Liv to arrive. Unless some huge emergency job pops up between now and then, I should be able to devote virtually my full attention to get the Liv tested and outfitted exactly as I want it. Should be fun!

Wayne
 

WayneC

Finding my (electric) wheels
Jul 4, 2007
7
0
Starkville, Mississippi USA
First Impressions of eZee Liv

The eZee Liv finally arrived yesterday by 18-wheeler. I was pleasantly surprised that the $200 freight charge from New York to Mississippi included delivery to my front door, even though I'm five miles in the country outside a small college town. I had expected to have to drive the 60 miles to the nearest UPS Freight terminal to pick up the package, but when UPS Freight finally called to say the Liv had arrived they said they would be delivering it to me the standard "between 8 am and 5 pm" that same day.

One other pleasant surprise is that eZee appears to have gotten the message that customers would rather have LED lights instead of the crappy wheel generator and halogen light setup. The Liv has both an LED headlight and LED taillight, with a switch for both on the battery charge status LED box. The Cats-Eye headlight I had already ordered will still be good to add, since its more concentrated beam is a good complement to the wide-beam Liv LED headlight.

This also simplifies the whole arrangement of experimenting with adding a small solar cell panel to at least extend the Liv's range. Due to an important out-of-town family wedding this weekend, I won't be able to do much more with the Liv until next Monday, but I'm very happy with my purchase so far. I'm putting together a full review to post on the forum review section, and it should be complete by later next week.

Wayne
 

flecc

Member
Oct 25, 2006
52,760
30,348
Comgratulations on your new Liv Wayne. I'm not surprised it has the LED lights as they've been on ours for a while now.

We'll look forward to your review once you've had some experience of it.
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