How to Solar Charge an Electric Bicycle

so I got a question we seem to be looking for step up buck convertors...what if we went from step down convertors. 50 volt panel then too step down convertor would this make charging the lifepo4 battery a better solution donw to 44 volts and say 2 or so amps...

mountain biker said:

so I got a question we seem to be looking for step up buck convertors...what if we went from step down convertors. 50 volt panel then too step down convertor would this make charging the lifepo4 battery a better solution donw to 44 volts and say 2 or so amps...

Click to expand...

So, Mr no punctuation, did you bother to even look at my other thread? Or are you just having a conversation with yourself?

Why would option 2 cost $1,300? something doesn’t add up right.

I have a option 2 system up and running most the time and it cost half that to build with new parts. Off the top of my head since i don't have the receipts to prove it the components cost.

20 Amp rated (10 Amp realisticly) MPPT charge controller $20
158 Watt 36 Cell monocrystalline panel $200
Group 34 lead acid battery $200 to $350 depending on it being AGM or flooded
Power inverter $40
Random bits $20

Total cost $480 to $630

System completely displaced use of a old 2 stroke generator while camping.

could you state what equipment your using, maybe giving us links. what you used and what didn't work. not trying to be judgemental but if you say so and so regulator went bad on because of this set up this could save other posters some heartaches with your knowledge and other posters will give you their experience so this can help you. that would be helpful. you said solar regulator..name brand, specs maybe cost,link to it etc. that would be helpful for this topic. also you mentioned 100 ah batteries and never specified how you could make this mobile. it is a variation of the original posters idea 2, which I think is cool, and I also think your idea is cool too. i.e. you might want to start a thread on syntax, you have mentioned it several times. also you mentioned you sold agm batteries and solar setup very cool, send me a link to the forsale area of this forum and someone might be interested in purchasing something from you because of your technical background and overall charming personality.


Details about Solar Panel Charge Controller Control Regulator 10A 12V 24V CE Certify
9 bucks
http://www.ebay.com/itm/Solar-Panel-Charge-Controller-Control-Regulator-10A-12V-24V-CE-Certify/111372080556?rt=nc
Brand new and high quality
Protection function: overload, short circuit, low voltage, lightning and overcharge protection

Color: black
Dimension: Approx. 10.3x9.5x4cm
Output voltage: DC 12/24V ( Automatically identify )
Current: 10A ( rated charging current )
Working temperature: -20°C ~ +60°C
Power supply stop voltage: 10.8V or 21.6V
Power supply recovery voltage: 11.8V or 23.6V
Charging stop voltage: 14V or 28V
Stop charging temperature coefficient: -3mV / ° C / cell


Package included
1 X CMP solar panel charge controller

DC to DC converter 100W Boost power supply Regulator Volt Amp meter usb output http://www.ebay.com/itm/DC-to-DC-converter-100W-Boost-power-supply-Regulator-Volt-Amp-meter-usb-output-/291273499330?pt=LH_DefaultDomain_0&hash=item43d140e2c2
20 bucks
DC to DC converter 100W Constant voltage and current Boost power supply module step up Voltage Regulator with Voltmeter ammeter usb output for Charging #1300205



Boost Constant voltage and current,

With voltage, current display,

Output with USB port With identification resistor,

Single lithium battery can be directly rise to 5V to charge the phone. Large output current 2.5A.




Module parameters:


Module Name: 100W boost constant current module


Module Properties: non-isolated step-up module (BOOST)


Input voltage: DC 3-35V (limit of 36V)


Input Current: 10A (MAX) ,Please enhance heat dissipation exceed 6A



Quiescent Current: 15mA excluding voltmeter current (12V rise 20V, the output voltage is higher quiescent current will increase)


Output voltage: DC 3-35V continuously adjustable



Output Current: 6A MAX ,exceed 5A Please enhance heat dissipation


Constant current range :0.1-10A


Output power: = Input voltage * 6A, such as: Input 3.8V * 6A = 22.8W, 5V * 6A = 30W,


12V * 6A = 72W, input 24V * 6A = 144W,


Operating temperature: -40 to +85 ° C (ambient temperature is too high, please enhance heat dissipation)




Operating Frequency: 280KHz


Conversion efficiency: max 96%



Over current protection: Yes (input exceeds 12A, automatically reduces the output voltage, have a range of error.)




Short circuit protection: (input 15A fuse) double circuit protection, use more secure.


input Reverse Polarity Protection: None, (if required in the input string into the diode)


Output preventionanti-irrigation: Yes, for charging plus blocking diode is not required.


identification resistor: Tablet PC, pad, phone (some phones identification circuit is different, need to be adjusted)


voltmeter minimum resolution: 0.05V/0.05A (10V following automatic switching decimal point)


Installation: 4 pcs 3mm screws


Wiring: no need welding output terminals


Module dimensions: length 60mm x width 50mm x height 20mm






Applications:




1, DIY a power supply, input 12V, output can be 12-35V adjustable with voltage and current display,




2, the power for your electronic devices, can according to your system set output voltage value.




3, as the vehicle power supply for your laptop, PDA, or a variety of digital products supply.




4, DIY a laptop mobile power supply: 12V coupled with high-capacity lithium batteries,




5, the solar panel regulator.




6, DIY high current mobile power with a single lithium battery can be boosted to 5V, comes with USB port and identification resistor, and a large current of 2.5A output to several phones simultaneously charging.


Instructions:




1, the voltage meter power supply options: you can choose via jumpers voltmeter provided by the input supply or output is provided (IN table is an input, OUT is the output table) lower voltage can reduce the loss voltmeter, the jump lines jumpered to remove the jumper cap, voltmeter does not work.




2, USB output port: USB interface board is connected directly to the output terminal for 3V l 5V, can be directly used to charge the phone, has been identified with resistance to note is that in using the USB output, make sure the output voltage is the voltage with your digital product line, remember! ! Otherwise it will burn your digital products.




3, shows the voltage and current switching: This module via a band switch display input voltage and output voltage and output current, VI represents the input voltage, VO represents the output voltage. Represents the output current IO.




Output current adjustment method:




1, regulating CV potentiometer, According to your battery or LED, the output voltage is set to your desired voltage value. Such as 5-string LED voltage regulator 18.5V, 27.6V tune bunches batteries and so on.




2, set CC potentiometer counterclockwise around 30 laps, the output current is set to minimum, connect the LED, adjust CC China locator to the desired current. For battery charging, the battery is discharged, and then connected to the output, adjust to your desired current CC, (for sure when charging the battery completely discharged before being allowed to adjust, because the battery charge remaining in Vietnam more, the charge current is smaller.) Please do not use short-circuit current way of adjusting the boost module circuit structure can not short-circuit the way tune.



packing includidng :

1x 100W boost constant current module

12 Volt 26Ah Deep Cycle Rechargeable Replacement Battery Wheelchair 12v
60 bucks
This listing is for (1) 12 Volt 26 Amp Hour battery



Product Description


Amp Hour: 26
Voltage: 12
Termination: NUT & BOLT
Chemistry: SEALED LEAD ACID
Color: FLAME RETARDENT
Weight: 18.35
Width: 6.5500
Length: 6.90
Height: 5.00

solar panel----199




Condition:
New: A brand-new, unused, unopened, undamaged item in its original packaging (where packaging is ... Read moreabout the condition
Brand:
ECO-WORTHY

Ipm:
5.6A
Model:
100W folding solar panel

Isc:
6.18A
MPN:
FP100-1

Size:
1029*690*36mm
Country/Region of Manufacture:
China

cell marterials:
polycrystallline
Voc:
22.41V

Frame:
Heavy duty aluminum
Vpm:
17.9V

size(open):
1029*690*36mm



okay....solar panel to charge regulator....then agm battery hooked up..then load out to step up convertor to 44 volts...
would this blow up my 36 volt lithium????

yeah I think the cost were based like 2011 price points and I believe the yeti is still around 1500 bucks for above system...goal zero. there really doesn
t seem to be a lot of options out there for this kind of thing even today....Walmart has about 4 different options with something that is solar and can charge more than a cell phone....I believe the yeti is like 60 watts solar panel with 50 ah battery agm. the Duracell one with 26 ah battery agm 12 volt 60 watt panel combo is like 300. bucks but i have got no response from Duracell yet on wether or not i can plug in the 36 volt battery of lifepo4 charger around 180 watt model or so. sorry...no response wether or not their invertor would destroy my charger and or battery? assuming there was enough juice to charge it.... i assume you can only use 40 percent of an agm right before you need to recharge it right or you could destroy the battery... or can you discharge more?

600W DC Boost Step Up Converter Car Laptop Note Book Power Supply 10-60V to 12-80V Voltage Regulator

http://www.prodctodc.com/600w-dc-boost-step-up-converter-car-laptop-note-book-power-supply-1060v-to-1280v-voltage-regulator-p-185.html#.VFHMD2PwvIU

Feature: •Input voltage: DC 10V-60V
•Input Current: 15A (Max)
•Output voltage: DC 12V-80V continuously adjustable
•Output current: 10A (Max) adjustable
•Output power: effective power P = input voltage V * 10A
•Conversion efficiency: up to 95% ( Input voltage and current; Output voltage and current will Affect the conversion efficiency)
•Short-circuit protection: fuse
•Dimension: 85x63x60mm
Note: •600W Refers to the maximum power of the module under specific conditions, In the case of different input voltage, The maximum output power declined by the maximum input current limit. For example
•Input Voltage 12V：Max Output Power P=12V*10A=120W
•Input Voltage 24V：Max Output Power P=24V*10A=240W
•Input Voltage 60V：Max Output Power P=60V*10A=600W
Some Applications: •DIY a output adjustable car power supply. input Car DC 12V, output can be DC 14-80V continuously adjustable. but the output voltage can not less than input voltage.
•Car Laptop Power Supply. input 12V, adjust the output voltage for the laptop/notebook.
•Booster charger. use 12V power for charging 24V battery. and the charging current could be adjusted.
•Powered for electronic devices.
Application Example: •Input 12V, 8.73A, output 20V, 5.0A, Efficiency about 86%
•Input 54V 13.5A, Output 58V 12A, Use 5Ω1Kw resistance as the load test, Efficiency 95%
Package Include: •1x DC Converter

okay hook up panel that is above is within specs 10 volts minimum...put panels on front and rear...now should I try to get panel volts close to battery charging 44 volt 5 amp or just not exceed my 10 amp limit and 44 volt limit? well battery has to be at 5 max...so then I need around 200 watts of panel????any guidance is helpful....thank ya.

mountain biker said:

yeah I think the cost were based like 2011 price points and I believe the yeti is still around 1500 bucks for above system...goal zero. there really doesn’t seem to be a lot of options out there for this kind of thing even today....

Click to expand...

That's why i home brew my systems from off the shelf parts. at any given time i could probably get 2 or 3 systems up and running off of what resides in my junk boxes. I do own a few goal zero products and there quality control is hit and miss. If you do decide to go the already made goal zero option i strongly suggest taking a photo of the sales receipt and keeping it in a safe place. I have had several experiences with reps while requesting warranty service and all have been painless, but i had photographic evidence of the purchase. I also like home brew systems because I'm not locked into a set of proprietary connecter and voltage standards, and the needed repair part is often only a junk box away.

mountain biker said:

Walmart has about 4 different options with something that is solar and can charge more than a cell phone....I believe the yeti is like 60 watts solar panel with 50 ah battery agm. the Duracell one with 26 ah battery agm 12 volt 60 watt panel combo is like 300. bucks

Click to expand...

In both those cases i think the battery size is on the too slim to way to small to be useful for charging a ebike battery. however that's subjective and depends on what kind of performance and life span you expect out of the system. In the case of the Duracell system ( that i have never seen ) the 60W panel is just enough to keep that battery happy if you have good weather. For the goal zero option you should budget for extra panels to bring the system up to 120W. My systems if I'm actually trying to size components correctly i aim to charge my main storage battery from flat to full in 5 hours max. But i will admit i don't always fallow my own rule and my battery suffers ( or sulfates ) as a result

mountain biker said:

but i have got no response from Duracell yet on wether or not i can plug in the 36 volt battery of lifepo4 charger around 180 watt model or so. sorry...no response wether or not their invertor would destroy my charger and or battery? assuming there was enough juice to charge it.... i assume you can only use 40 percent of an agm right before you need to recharge it right or you could destroy the battery... or can you discharge more?

Click to expand...

Honestly when asking a manufacture technical questions about there product good spelling and grammar does help. But as far as if your charger will work off of there inverter i would start by looking at the charger. Is it a solid state unit or does it have a transformer? If solid state odds are quite good it will work just fine or even better on modified sine wave. Square wave inverters are quite rare these days but i don't think you would run into any problems with those as well. The lest likely to give you any problems is a true sine wave inverter. The product literature should say what kind of inverter it has and what wattage its ratted at. Oh if it does have a transformer square wave is a no go. and modified sine wave a favorable maybe. Just get a palm of hand base line on how warm or hot the charger runs on true sine wave and compare that to what it does while running on the inverter. If its much hotter running on the inverter odds are its not happy with the situation. And hears a surprise, My Bionx charger actually pulls less power on the AC side and runs cooler while running on a modified sine inverter.

As far as how far can you discharge a AGM or any other lead acid battery... That's again subjective and depends on what you expect or want out of it. I'm going to state how i approach the matter but i guarantee someone somewhere will probably disagree with me and even be able to come up with facts figures and data to support there argument. But hear goes my couple of pennies.

The only way to not damage a AGM or any other lead acid battery is to always keep it on a battery maintainer in a cool dry location and never use it for anything.... sound useful to you? And even then it will probably die in its sleep inside of 4 or 5 years even just doing that. Would you like to live like that or would you rather have a somewhat shorter life and a few battle scars and stories to go along with them? Ok I guess I'm being silly but you get the idea so now I'm going to give a couple examples.

Number 1. You want to build a smaller more compact and portable setup for say charging a bike at a camp sight. The system might get used on one or two camping trips a month for say 4 months out of the year. That might be something like ohh (2x4x2=16) lets just say 20 days total use for the year to account for 3 day weekends and mystery flues on Friday. Over 5 years that's (5x20=100) cycles. Well if you look at the expected cycle life of a good AGM battery at 100% depth of discharge most will be rated at 200 cycles or more till they have lost 20% of capacity. So while this kind of treatment might not be kind to the batteries cycle count it will likely live to the ripe old age of 4 or 5 years old all the same. Just remember to keep it on a maintainer when not in use. In this example I'm talking about being abusive not neglectful.

Example number 2. Say you want to set up a system to solar charge your commuter rig while while avoiding use of the power grid for what ever reason you fancy. In this case lets assume your bike has a 500Wh battery and that it takes 750Wh from the lead acid battery to charge it. ( for the record i do advocate direct solar charging if feasible) And we also assume that you ride the bike 7 days a week because lets face it staying home on the weekends is not all that fun. we would need from the battery 750Wh multiplied by 7 to equal 5250Wh or 5.25KWh from the battery every week. From hear the numbers for a system just to run a ebike on solar start to get kind of intimidating if you want to guarantee a reliable system. Where i live you count your self lucky if you get 1 sunny day in the week for your solar system to crank up some juice. And also we want are battery to stay healthy and live a long life so we don't want to go below 50% depth of discharge. So were talking about a 10KWh battery hear. and to fallow my rule about being able to fill that battery from 0% to 100% in 5 hours you would need get this... a 2KW solar system. ( you can see why people that live off grid keep a well maintained backup generator on hand now can't you :wink: ) In this case the battery will I'm quite sure run for 1,000s of cycles and last for many many years.

But there is also lots and lots of " middle ground " in system sizing. You just have to educate your self about what it is that you want and what you consider to be tolerable system reliability. The example 1 system i have experience with running a trolling motor on a small fishing boat. The second example actually ran my uncles house at 80% reliability, forcing a generator day after 3 consecutive cloudy days. And no you don't want to know what a 100% reliable off grid solar system for a house will cost.

yeah....100 percent reliable off gride house...I don't even want to think about it (crazy dollars....)because here is an option for the on the road bike.(crazy dollars)

36 volts 20 ah- to charge--maybe 720 watts lifepo4 battery with bms....(lets say yeah your off the grid and the bad roads require more wattage and battery life)

gensun 8 specally built boost convetor mppt charger for 36 volt...they make stock 48 or 24 volt for lifepo4...lifepo4=320 for 36 volt 300 for 48 or 12 or 24 volt...
use any panel you want with this system.12 volt 24 volt cant exceed 30 amps or less than 10 volts (I don't think you can exceed the voltage of say 44 volts for lifepo4 booster charger. up to 350 watts maxx input.
350 watts lets say half of that any given sunday is given off....probably lose some to battery inefficiency.. gives us 44 volts times 2 amps 88 wats...3 amp 136watts...4 amps...maybe up to 4 amp charge at 44 volts....but two or three would work for a lot of batteries advertised for bikes.
1 dollar a watt 350..2 dollar a watt 700....3 dollar watt neo tech,small sleek....1050
now to diminish te 100 percent reliability.....will the bms of lifepo4 allow to charge and discharge at same time....can the booster mppt charge and discharge through its load output at same time without messing up the battery bms???
so then we need a duplicate system to have one charge then one run......


I could proably fit one panel in front and one in back of bike...lets say two panels 2foot by 3 foot???......ridicually large 700 bucks...ultra small and slick 1050.
cost 320 mppt booster
670 for panels 350 watts (add 20 bucks for on the road soldering gun)
1370--non sailboat look
1020 for prepper shack panel array.

forgetting to not attempt to put gensun 8 lithium in waterproofing type box or boxes, burning it up....priceless....f
and perhaps replicating the system. double the cost...not to mention the cost of the bicycle and the added stresses from weight and wind force from panels...
and why not add another 20 ah battery to double the capcity..so you can get another ride or two after dark....

where is the amortirization calculator that uncle sam uses for this kind of stuff????

Bioenno Power 12V/24V, 20A Solar Controller for LiFePO4 (Lithium Iron Phosphate) Batteries

this company makes a 48 volt lifepo4 charger around 50 bucks now...they always made 12 and 24 volt....very cool.

Bioenno Power 12V/24V, 20A Solar Controller for LiFePO4 (Lithium Iron Phosphate) Batteries

this company now makes a 48 lifepo4 solar charger....they always made 12 and 24 volt....for around 50 bucks

mountain biker said:

Bioenno Power 12V/24V, 20A Solar Controller for LiFePO4

Click to expand...

Go Cali. (Watt produced the "mountain bike" over 30 years ago, plus lately, seems they are enjoying current object of Ebiker Lust, the "Cruiser Bike" (recumbent trike).)

okay...lets theortically use this buenno system...I would go for a 48 volt system.....now I believe the company said it does not regulate amps...so what I put in is what I get. not quite for sure what kind of lose is involved but....I guesse a question would be the specs say panels up to 100 volts...my battery can only take up to say 2 amps or so maybe 3.... so then...how would you guys play this. I guesse my goal is what 55 volts 3 amps. is what specs are on some batteries....

how would you guys size this to get maximum power and I wonder if volts go through this thing...100 volt panel pushes...100 volts to battery or would it regulate it to.....

bioenno

"Dutch Solar Cycle Electric Bike: Never Plug In?!":
http://electricbikereport.com/dutch-solar-cycle/

lol. loving it....126,000 usa bucks???? wow.... pretty cool. and I thought 48 volt batteries were expensive. I am wondering who were the 50 or so who bought the bike?

LockH said:

"Dutch Solar Cycle Electric Bike: Never Plug In?!":
http://electricbikereport.com/dutch-solar-cycle/

Click to expand...

this is Albert van Dalen who made the schematic of the kingpan charger for us and has the EV website. he is a member here, doesn't post anymore.

Some simple math will tell you that is a colossal waste of time unless you are looking for publicity in which case is May have some merit.

Thanks for the many prior suggestions. Now that I'm past my MAC/Trek build and have my burly travoy styled trailer completed & road tested, I'm preparing for the next step towards my East Coast Greenway cross-country solar ebike camping tour. That would be the investment in solar panel and an MPPT solar charge controller to match the mix. So, thinking about the model GVB-8-Li-**.*V solar boost charge controller from batteryspace.com.

If I'm reading this right, I should be able to charge a 48V LiFePO4 battery with a maximum of 350 watts of solar panel.
I'm looking at these Renogy 100W Monocrystalline Bendable Solar Panels. Per suggestion on form factor at 12V per and a mere 4 lbs and 41.3 X 21.3 inches, to fit nicely as part of my touring pack. Still the high-efficiency SunPower solar cells.

Looking at this combo, I believe that I can put three of these panels in series. Four would exceed the maximum power & open-circuit voltage of the controller. Or not?

So, given that 3*100 watts or 300 watts of charging capacity and my 2 * 48V * 20ah, ~1000 watt-hour battery and two of them, should take about 7-8 hours of charging with this setup. Huh? I figure I'll be able to do about 50 miles a day, which will take me about 2-3 hours. Morning ride, setup camp and start charging one battery. Visit the area on the other battery, then switch. Its a plan at least.

transamericanelectricbiketour.com tips, summarized:

1. Everything has a way of working itself out.
2. You can find good people everywhere.
3. It can be done – one mile at a time!
4. Bungee cords and duct tape save the day.
5. Just ask, and you’ll be surprised what you’ll receive.
6. Don’t make excuses — just go for it.

1. The value of a “Coke break.”
2. Audiobooks are great.
3. Pack lightly when you can.
4. Don’t expect it to be great the entire time.
5. Don’t be afraid to be alone.
6. Pick your partners well

Click to expand...

I think you will like those panels from Renogy. I love mine. They are only marginally bendable being pretty darn stiff. That was what I wanted for my application where I wanted them to stay flat.

Be careful about putting panels in series. If illumination is not equal, you will be disappointed with the output.

I will be very interested in any results you get with the MPPT controller. I used a simple DC-to-DC converter set to the battery max voltage (42V) and got decent but not great efficiency. When the battery was low, the DC-to-DC converter was loaded down to run slightly above battery voltage and pulled the panels well below Vmp, but instead ran close to Isc.

More info if you are interested at: http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=62700

Thanks. Do you think I should put 4 of them in series to get the needed voltage and forget approaching max V for the MPPT?

The MPPT shows a design input of 8A so putting the panels in parallel is probably a bad idea.

Max voltage of 63V would put you pretty close with 3 panels -- at the end of charge when the voltage on the panels will approach Voc. 4 panels would be WAY over the 63V and probably a bad idea.

wire 2 pairs of panels in series and then wire the two sets in parallel for ~12A at 15V under load is closer but now you violate the 8A limit on the MPPT. I have done that kind of thing but I had an open design and I could make SURE there was plenty of cooling. I don't know about long term reliability.

If you can get them all to have the same illumination -- one big (80" x 40") flat surface then the series/parallel question is not such a big deal. If they are NOT on the same flat surface, then wire those that ARE on the same surface in series and wire the sets in parallel with blocking diodes to keep the better-illuminated panel set from back-driving the other panel set (I am thinking of a pup-tent like geometry over the top of your trailer). When you are stopped you can make the pup tent into a single surface by raising one side and pointing that to the sun as best you can.

I really think 4 panels is overkill. With my 36V 13Ah Bionx system and 200W of panels in Arizona summer I was figuring on a trip like this:
1. Start at 8am and ride 30 miles (2 hours) -- mostly on battery and very moderate leg power
2. Break for 2 hours (tipping panels into the sun) -- charging battery to 1/2 full or better.
3. 11am-2pm ride 30 more miles mostly solar and very moderate leg power (stopping and tipping panels to sun periodically) battery should stay roughly constant at half full.
4. 2pm stop for the day and tip panels to sun to fully charge battery for next day.

From the performance I got with two panels, this trip looked very do-able with a fair bit of margin.

Hey thanks for the feedback. I'll stick with the plan of 3 in series then and see if it all works. Glad to know there's at least one other person doing the solar eBike camping thing. Will post on how it all works out.

Still wanna see if old hub motor can be rewired (if necessary) to be spun as a generator by a Savonius rotor. (On theory that winds still blow on cloudy days and at night.)

I'm charging with 100% wind power right now. Solar will give me an extraordinary new dimension of personal freedom. Go anywhere without worry and never buy another drop of oil again (except for my chilli & other food/drink, which has that continued dependency).