How to Solar Charge an Electric Bicycle

The panel brand uses the top of the line cells, so that's good. I would try avoiding flex of the panels, because back and forth flexing shatter solar cells. The flexible part is really so they're ok to glue down onto a gently curved surface and leave them there, so for yours I'd fix one to have a rigid back and strap the others to it.

I do have a problem with the voltage, which is too high for directly running something at 12V. Those come in all kinds of sizes, so getting the right voltage is easy. Have the multiple panels in series match your pack voltage well, since the less conversion of voltage the more efficient things get.

While camping do you want to be able to unhook the trailer and take of with just the bike? That's the only justification I ever see for trailers. Towing them increases rolling resistance and wind resistance pretty dramatically, so my vote is for a cargo bike instead, which to me is an all-around more practical and useful vehicle. OTOH a very aero cargo trailer that is broad and flatish and long to be able to "fly" a significant panel area is intriguing, but the extra wheels on the ground and air resistance are formidable challenges to avoid a net power deficit compared to a cargo bike and much less panel area in service while riding.

What duration of trips are you considering? I can't think of occasions where an electric fridge wins out over a low tech ice chest, not using a lightweight vehicle like an ebike.

I look forward to your results. Our boys are finally big enough for the guys to head out like that, so come up with some great stuff to copy.

John

Thanks again for the sage advice. I'm gearing up for long. Plan is still the East Coast Greenway, a once-in-life grand adventure. I'll put an aerodynamic cap on the trailer to reduce resistance. May do some other things like that, but going fast is not my aim. I plan slow, meandering, meaningful. But I hear & appreciate your opinion on trailer versus cargo bike build. And yes, definitely a setup camp, start the charge and take off on the bike to explore the area kindof schedule. Find places of extraordinary beauty and suck it up.

so then do you use a dc to dc convertor... like say 12 volt solar panel 2 amps...that's 24 watts... where can you find these dc to dc convertors...so solar panel to dc onvert to dc then to input of lifepo4 battery that has bms built in...so 36 volt 10 amp batterys would be like 15 hours in prime time sunlight mayabe 2 or 3 or 4 days. but its still a charge..


or do you do three series of 12 volts...so you get close to the battery of 36 volts and amps what would you recommend...isn't lifepo4 the ma charge like 4 amps or something...

I guesee....what is a good dc to dc solution....no ac

http://www.batteryspace.com/105-350w-solar-boost-charge-controller-with-mppt-for-lithium-batteries.aspx

Specifications

GVB-8-Pb-12V GVB-8-Pb-24V GVB-8-Pb-36V GVB-8-Pb-48V GVB-8-Li-**.*V
Rated Panel (Input) Current: 8A 8A
Minimum Panel Voltage for Charging: 5V 5V
Minimum Battery Voltage for Operation: 9.5V 9.5V
Absolute Maximum Panel Open-Circuit Voltage (Voc): 63V 63V
Charge Profile: Multi-Stage with Temperature Compensation CC-CV
Nominal Battery Voltage: 12V 24V 36V 48V (See specs for closest -Pb equivalent.)
Maximum Recommended Panel Vmp: 13V 26V 41V 43V
Maximum Recommended Panel Power (8A Panel w/~155mm cells): 105W 210W 325W 350W
Bulk Voltage: 14.4V 28.8V 43.2V 57.6V —
Absorption Voltage: 14.2V 28.4V 42.6V 56.8V —
Absorption Time: 2 Hours —
Float Voltage (Pb models) or CV Voltage (Li models): 13.8V 27.6V 41.4V 55.2V **.*V as specified in part number
Battery Temperature Compensation: -28mV/°C -56mV/°C -84mV/°C -112mV/°C —
Electrical Efficiency: 95% - 97% typical 96% - 98% typical 96% - 98% typical 96% - 99% typical (See specs for closest -Pb equivalent.)
Night Consumption: 7mA 6mA 6mA 5mA
Tracking Efficiency: 99+% typical 99+% typical
MPPT Tracking Speed: 15Hz 15Hz
Marine Grade: Yes Yes
Waterproof: NO NO NO
Connection: 4-position terminal block for 10-30AWG wire
Weight: 6.5oz., 185g
Dimensions: 5.5x2.5x1.2", 14x6.5x3.1cm
Warranty: 5 years


Specifications: Please click here to download user manual



Overview

The industry's most efficient boost controllers. These controllers boost lower-voltage solar panels up to charge higher voltage lithium batteries up to 48V nominal
•8A 12/24/36/48V Boost MPPT Controller
•99% Peak Efficiency
•Continuous MPPT
•Marine-Grade
•Advanced electronic protections
•5-Year Warranty.


GV-Boost 105-350W MPPT Solar Boost Charge Controller for Lithium Batteries

Want to see a 27V grid-tie panel charge a 48V battery pack? Get a GVB.
Most solar charge controllers move power from a higher voltage panel to a lower voltage battery bank. The GVB-series controllers, in contrast, pump electricity up hill. These controllers will take a standard 12V panel and boost the voltage to charge a 24V, 36V or 48V battery pack. In fact, the GVB's will work with almost any panel that's below your battery voltage. This makes finding a good panel easy: just make sure to stay below 8A panel current and 63 Volts (open circuit). Larger panels are cheaper per Watt than smaller panels, so using one large panel and a boost controller results in a significantly lower system cost than smaller panels in series with a conventional charge controller.

Mission-Critical Reliability
GVB controllers are deployed to the most remote locations on earth. They endure years at sea, harsh Antarctic winters, freezing conditions in the upper atmosphere on solar powered airplanes, and in a few off-the-map locations. Made in the USA, each controller is put through complete electrical testing to ensure reliability. If you need mission-critical power, this is your controller.

High-Speed MPPT: Always on Target
Not all Maximum Power Point Tracking controllers were created equally. Most use a sweep and sleep method that scans the entire voltage range every 30-60 seconds. That's okay for a clear day, with a stationary panel. But moving vehicles and changing cloud cover require a faster, more advanced controller. The controllers adapt to changing light conditions 15 times every second. They are always on target, capturing every bit of available sunshine. Simply put, other controllers can't keep up.

Advanced Lithium Charging Algorithms
Drawing on years of advanced lithium battery development, we offers a complete line of lithium solar charge controllers. These units efficiently charge our high-performance lithium battery packs, and many other commercially available lithium battery systems.

Custom Voltages Available
We stocks the GV-Boost in 24V and 48V nominal charge profile for the LiFePO4 chemistry used in our Marine Lithium batteries. Custom voltages can be programmed at the factory to match the float Voltage (CV voltage) of your battery chemistry. Please select the Custom Voltage option from the drop down, and email sales@batteryspace.com to specify the voltage.

Made in the USA

Proven charge controllers:http://www.morningstarcorp.com/products/

hey appreciate that..yeah Morningstar has good name recognition...basically offgrid online store ranks them highly...my question is how do you use one and what model to charge a 36 volt lifepo4 battery?

hybrid option 1 and 2

grid tie to buy you enough time to wean yourself off the power company's teat. then completely off grid. further feed the "matrix"? last time i checked, we have no vote, no voice on how it would be distributed. more wars in the middle-east? asian pivot? russian threat? no thanks. we are already feeding this debt-based corporatocracy with our physical energy like human batteries. naive to think the energy would be nobly shared. lions share goes to military industrial complex and large conglomerates (monsanto?).

elites would be delighted see the sheeple spending their hard earned fiat currency on expensive panels and feeding our precious electrons back into their pockets. how much are they going to pay you? how much do they make when they resell your energy to upstream, upscale carnivores? who will have priority access to the energy in the event of a crisis? one cannot only look at this from an engineer's lab scope. gotta understand the hidden geo-political, macro-economic agendas (google "zeitgeist").

sooner we become self-sufficient (ie. remove the demand), sooner the centrally controlled power authorities will crumble and only then we can begin to rebuild new decentralized structures that are not based on artificial scarcity. we need to accelerate the process of empowerment (the meek shall inherit the earth) not prolong the fear-based, strangle-hold of these abstract systems of political and economic governance. independence and empowerment--that is why i built my ebike. how about you?

http://www.duracellpower.com/portable-power/power-packs/powerpack-600.aspx
its a Duracell powerpack 600 sealed agm battery 30 ah...

you can plug in a 60 volt panel but also has a carcharging port...it says like 4 hours on carcharging port.....14 or 15 volts is a car running right...so that like 10 amps coming out of the charger???? seems like a lot...but that would get you 600 watts in about 4 hours......

so hook the panel up as should be..... also read somewhere that people would get the connector type for the ac charger portion( ac to dc wall charger) of this and run the solar panel on that so you could user bigger panel or so... or plug in to car charger full on....140 watts it sounds like it could take that would be wild....

22 pounds ,,,has solar plug in.... man heavy but kinda interesting if your just looking for a cruiser of mtb,bugout vehicle,,mount this on frame ...heavy..but... hook lifepo4 batteries ac charger to this things....its got the watts....showed a dude watching an old tube tv on add.....
also has a light.....
talking about something that could make good use of
SKU DRPP600
UPC 609525760491
Dimensions (L x W x H) 14.6 x 9.3 x 11.5 (in)
Weight (including DC output cable) 22 lbs
Battery Chemistry SLA (AGM)
Battery Capacity 26Ah
Light Fixed LED Light
Overload & overtemperature
protection Yes
# of AC outlets 3
# of DC outlets 1
USB-port 2 x 2100mA
AC output power
(max. continuous) 480 W
AC output power (peak) 600 W
AC output surge capacity (peak) 960 W
AC output voltage (nominal) 115 V
AC output frequency 60 Hz
Charging time from AC outlet 35 h (max)
Charging time from DC outlet 4 h (max)

sorry 60 watt panel is what they are selling but you can use any panel around 12 volts 5 amps according to posters on amazon.com. not recommened to charge while this device is being used but said it could be done by a poster....just wonder how many chargers you can get out of the agm battery????

mountain biker said:

http://www.duracellpower.com/portable-power/power-packs/powerpack-600.aspx
its a Duracell powerpack 600 sealed agm battery 30 ah...

you can plug in a 60 volt panel but also has a carcharging port...it says like 4 hours on carcharging port.....14 or 15 volts is a car running right...so that like 10 amps coming out of the charger???? seems like a lot...but that would get you 600 watts in about 4 hours......

so hook the panel up as should be..... also read somewhere that people would get the connector type for the ac charger portion( ac to dc wall charger) of this and run the solar panel on that so you could user bigger panel or so... or plug in to car charger full on....140 watts it sounds like it could take that would be wild....

22 pounds ,,,has solar plug in.... man heavy but kinda interesting if your just looking for a cruiser of mtb,bugout vehicle,,mount this on frame ...heavy..but... hook lifepo4 batteries ac charger to this things....its got the watts....showed a dude watching an old tube tv on add.....
also has a light.....
talking about something that could make good use of
SKU DRPP600
UPC 609525760491
Dimensions (L x W x H) 14.6 x 9.3 x 11.5 (in)
Weight (including DC output cable) 22 lbs
Battery Chemistry SLA (AGM)
Battery Capacity 26Ah
Light Fixed LED Light
Overload & overtemperature
protection Yes
# of AC outlets 3
# of DC outlets 1
USB-port 2 x 2100mA
AC output power
(max. continuous) 480 W
AC output power (peak) 600 W
AC output surge capacity (peak) 960 W
AC output voltage (nominal) 115 V
AC output frequency 60 Hz
Charging time from AC outlet 35 h (max)
Charging time from DC outlet 4 h (max)

Click to expand...

If you could construct a proper sentence we might understand what you are trying to say.
Just spewing out thoughts which only make sense to you is a waste of time.
As a guide watts, amps, and volts are not the same thing, ........right!

sorry typo on 60 volt statement...corrected it on next post... go to the website on top of page is their official site also check out amazon.com for comments on this product..

and it looks like this charger is only 30 watts...

solar specs were like 17 volts max.. almost 3 amps on max amps....

I thought I read somewhere someone hooked up a 100 watt panel into the car charging part. however Duracell does not support or recommend that. still. there could be some room to get a few more watts or amps.....

anyone know what a car charger puts out in volts and amps...I know a lot of variables...my camry puts out around 14 volts and 11 amps...so like 150 watts or so.....I think this is where they say you can charge this thing with a car charger in about 4 hours.. the blogs on amazon say anything bove 18 volts hurts the Duracell battery... another poster says any 12 volt array will work. another poster says you need to regulate power if your using anything bigger.... plugging 150 watts of power from a 12 volt solar array into charger sounds interesting.... not quite for sure but I thought I read a poster says the things maximum charging through panel is something like 2.5 amps...apparently you plug in the panel where you would plug in the ac to dc wall charger....

a lot of variables here...but man if you had one of those double speed motors you might be able to get away with this if you didn't mind going 10 mph unassisted...keep it in first gear...

http://www.amazon.com/Duracell-600-Watt-Powerpack-Pro/dp/B009YR00MI/ref=sr_1_1?s=automotive&ie=UTF8&qid=1414250329&sr=1-1&keywords=duracell+solar+charger#productDetails

Shesh, I guess we can blame the education system.

What you are looking at is a battery in a fancy box. Probably a $25 SLA battery. You really don't need a massive battery to jump start a car. Expensive and pretty much a waste of time for anything except the odd jump start and maybe a light.

lol.... read up on the specs from official websites and url posted and if your interested you can comment on the topic of this thread.


looking like there may be a pro version and regular version and one with an air compressor...

they are all reading around 23 or 26 or 29 amp hour agm battery.... at around 12 volt or so...

one poster said he was able to take it to a battery outlet type store and have his battery replaced..

this seems very similar to the goal zero equipment but its about 60 percent the cost.

there is a goal zero posting with an offgrid type store...that basically is talking about the same setup....use their yeti brand equipment, the total for something similar was about 1500 bucks and neither one has officially said their stuff is waterproof. so you would need to add a few duffle bags or something to make this truly waterresistent.

this also will lead to waterproofing everything...if your bike is to sit in the sun with a panel. all controllers must be waterproofed motor everything etc... saw a few threads on this thing... do like the idea of having a long wire on panel..the Duracell 600 has a 25 foot wire now.... that way you could put the bike in a garage or something or porch or inside and let the panels work outside on the rainy slash cloudy days catching the rays when they can and not get the bike wet...

I do like this yeta/duracel/powerwagon.... idea... granted their 30 watt solar panel is obviously low but with the battery back up with three ways to charge...car charger, solar panel and ac this makes your bike pretty mobile. plus you can charge your cell phone and run a tv for a few hours if you wanted to. also you could use the solar power in essence to jump start a car on the highway if you were biking...this would be good for biker karma.

There's this thread... How to Solar Charge an Electric Bicycle which was a decent post:

solbike said:

There are four ways to solar charge a lithium ion battery that I know of; please comment if you know of others or better ways. Each has their advantages and disadvantages. A difficulty with solar charging lithium ion batteries for electric bicycles is that the best voltage to use for motor powers from 200W to 500W is 36V. This in nearly exclusively a voltage used for electric bicycles and it's near impossible to find commercially available systems for charging this voltage with care needed to make sure it's suitable for lithium ion chemistry (36V regulators for lead acid batteries can be found, many of these regulators can be set at 12, 24, 36 or 48V).

Here are the methods I can think of with their approximate prices and pros and cons -

1) Get a standard grid connected solar system and then use your charger from the mains power. Approximately $3000 for a 1.5kW system in Australia with current government rebate scheme. Advantages - can charge at any time you like, excess energy fed to grid and you get paid for it. Disadvantages - you need to own a home and have a spare 3K, nothing elegant about it, losses through the system through inverter, AC to DC conversions.

2) Get a 12V 80-100W panel, a 5-10A solar regulator, a 80-120Ah deep cycle lead acid (AGM) battery, an ~300W inverter (modified or true sine wave, both seem to work).Connect all of these items together then connect your regular charger to the inverter. Approximately $1300. Advantages - can charge anytime you like, system can be used for other applications, relatively small, can possibly be put in a trailer for cross county touring. Disadvantages - need an extra storage battery, losses through AC/DC conversions.

3) Get a 36-48V panel. Have an electrician construct a regulator to drop the voltage to float at approximately 42.5V. This is the voltage the regular charger puts out, I've found it to charge batteries fully and not over charge them. I've been using such a system daily for about 4 months. I don't know what the long term damage may be but nothing's exploded yet and range is still fine.If using a 100W panel (48V), then it'll take about 6-26 hours of sun to fully charge a 36V 10Ah battery from dead flat. Approximately $650. Advantages - Quite elegant direct system, can be mounted at work or home and you'll never have to charge from mains if you're in a sunny zone within bombing range of your charging capacity. Disadvantages - When the bike isn't connected the energy created is lost, can't re-charge at night, need to find an electrician to create a step down regulator to match your panel.

4) Get 10W panels (about the largest size you can comfortably attach to a bike) cut specifically to give a closed circuit voltage of ~ 42-43V open circuit voltage of about 50V) - connect this straight to the bike battery. Some Chinese factories will do this if you promise it's just a test sample and you'll by hundreds (of containers full!). Approximately $100. Advantages - small and can be put on a bicycle (see picture), most efficient use of panel energy. Disadvantages - will only allow about 1km travel per hour in the sun, un-regulated system is probably not ideal and could cause battery damage over time (though so far so good).

I've put these methods in a video (it's near the end of the conversion kit video at about 14min into this youtube clip posted here):
http://www.youtube.com/watch?v=N58Jq77-E4k

Matt - Solar Bike - http://www.solarbike.com.au

Click to expand...

I think what I can glean from your jumble of disconnected text is you like the setup. That's great. So go and buy one and give us a review.
Try using syntax we can understand.

lol.... loving it... the original poster I believe his second option was a similar setup. just trying to contribute to topix related to this forum. perhaps you would be interested in doing the same.
trying to get a price from alibaba..this one looks pretty cool. damp proof...12 volt 48 amp hour....nice...lithium battery...and I believe 100 watt panel..12 kilograms weight....solar panel is 50 watt and weighs 13 kilograms.... so we got 25 kilograms..sounds very heavy on panel....

below is what I got from their website.specs

http://www.alibaba.com/product-detail/off-grid-solar-generator-portable-350w_1873150286.html
Place of Origin:
Guangdong China (Mainland)
Brand Name:
Risen
Model Number:
BX007

Specification:
Mini
Application:
Commercial
Output Voltage (V):
100V-240V

Load Power (W):
350W
Solar Power (W):
50W
Work Time (h):
8-10

Description::
350w solar generators portable
Battery::
lithium polymer battery 12V48Ah
Solar panel::
Monocrystalline solar panel 50W

Inverter::
Pure sine wave inverter 350W
Output::
AC/DC power supply
Feature::
Portable, light-weight, integrated design, AC/DC power

Color::
Dark grey, other color please contact us;
Weight::
12kg;
Type::
solar generators portable,

Product name::
solar generators portable, solar generators portable



Packaging & Delivery

Packaging Detail: Product size: 442*345*145mm Package size: 472*375*165mm White carton Product weight: Net Weight: 12kg; Gross Weight: 13kg; solar generators portable
Delivery Detail: 7-15days after order confirmation


Specifications

IP65 waterproof;
high portability;
low weight;
High work temperature;
350w solar generators portable


off grid solar generator portable, 350w solar generators portable, solar generators portable








Product Description

Specification:

Solar panel: 50W/18V PET laminated Monocrystalline;

Battery: 12V48Ah li polymer battery;

Controller: 12V/8A PWM Charge Controller;

Inverter: Pure sine wave 350W inverter ;

Output: DC5V/12V, and AC100V-240V, 50/60Hz optional;

Function:

AC: As long as the equipment power is less than 350Watt, such as: TV/Laptop/Desktop/TV satallite receiver/Fridge/Fan etc.;

DC: DC devices that is less than 5Amp work current.

Application Range:

Camping/Hiking/Travelling in canravas/Military/Emergency power/Disasters/Earthquake/Flood/Off grid areas etc.

Features:

Integrated design, light weight, makes it very easy for carrying!

Lithium battery, with long lifespan, can be replaced easily after its service period.

IP65 Waterproof, no worry for being dampened by the rainy weather or water;

AC/DC power supply, so no problem for working/travelling during the power outage or off grid areas.

Can withstand high work temperature, temperature protection level: 70degree;

off grid solar generator portable, 350w solar generators

concerning the Duracell 600 watt generator another website shows a 62 watt solar panel they plug into the Duracell 600.
http://www.earthtechproducts.com/portable-solar-power-system.html

The 62 Watt Sunlinq Foldable Solar Panel will completely charge the 600W PowerPack in approximately 7-9 hours providing up to 8 hours of runtime for a 25 Watt Laptop Computer while 4 hours of sun will charge the PowerPack halfway for 4 hours of runtime. Our Portable Solar Power System includes all cables for a simple plug n play system. Simply connect the Solar Panel to the PowerPack 600 via the DC adaptor (male cigarette lighter adaptor) and your ready to go! The Portable PowerPack 600 also comes with an AC Charger to recharge from a standard wall outlet and a DC Charging Cable to recharge from your car, truck, boat or small RV
panel specs...
Folded: Length 14.5" x Width 8.5" x Thickness 1.4"
Deployed: Length 52.5" x Width 30" x Thickness .01"
Weight: 3.1 lbs
Solar Panel Power:
Voltage: 12 Volts
Wattage: 62 Watts
Amperage: Amperage: 3.1 Amps
Solar Panel Materials:
Solar Cells: Flexible CIGS
Weatherproof: YES
UV Resistant: YES

Powerpack Specifications:
Dimensions: 14.6" x 9.3" x 11.5" H
Weight: 22 lbs.
Wattage: 600 Watts
Battery: Sealed, non-spillable 26 amp-hour AGM battery
Inverter: Built-in 600 watt inverter

I believe their price was 1299...yeah 1300 bucks... whats weird the 600 powerback was like 250 so they are saying the foldable panel is worth around a grand??? specs on it above 12 volts 3 amps......looks like 36 watts or so..sunny day maybe 15 volts 4.5 amps?

Solar Cells: Flexible CIGS

Click to expand...

IF the PV cells are latest generation with high 20%'s efficiency sure!!

mountain biker said:

lol.... loving it... the original poster I believe his second option was a similar setup. just trying to contribute to topix related to this forum. perhaps you would be interested in doing the same.

Click to expand...

My apologies if English is not your first language but you are very difficult to understand. English is a wonderful language if we all follow the rules.
I was employed in the solar industry in the early 90s for 3 years and have been involved off and on ever since.
I bought my first solar cells in the 70s making a basic solar panel.
I have had solar panels generating power since the late 80s in various application and still have a set of my original panels still generating power. I think I know what I am talking about.

I have done some testing in this area with Lipo batteries on an ebike, please see my other thread.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=64268

http://www.walmart.com/ip/ePower-EE860WSP-600WH-Solar-High-Power-Generator-Self-Contained-Portable-Unit-with-LiFePO4-Battery/35869430

Designed and Built as a Self-Contained Unit
• Power Capacity Extendable
• LiFePO4 Battery, 600WH Capacity
• 60W Power load for 10HRS
• IPM - Intelligent Power Management, 60W/17Vmpp solar panel, DIY Mounting
• 1 Year Limited Warranty/
700 bucks kinda pricey. there are no reviews on the Walmart site and I didn't find any reviews on it...


however they look like they are putting out 12 volts and 5 amps roughly...you could run this through a buck convertor/boost convertor..36 volt 1.5 amps to charge up the lithium battery.....then let bms deal with charge.

wouldn't it be nice if they made this in a 36 volt 10 ah format????

Not much information of how the thing is assembled. If the battery is tucked under the panel it could be a disaster overheating the battery.
A better arrangement is to have the battery and regulator away from the panel in a sheltered area where they won't get hot.
I sell a folding panel system 85 watts with regulator cable and a carry bag for A$299. It is designed to charge a lead acid battery, you can pick up a pretty good 12v 100ah deep cycle battery for $200.

yeah on that last one I was wondering where they were keeping the battery...looking at the pic and the info you would assume its underthe panel.... now 100ah agm battery sound heavy. do you put it on a small wagon or something? then how do you charge the set bicycle set up? ideally I would like panel cut to voltage of 36 panel and keep it under 3 amps or so..i would love to hear stories of the guys that have been doing that for a while...seeing if it hurts the lifepo4. I talked to gensun yesterday they said they $320 they can do a boost converto rmppt for solar and charge a lithium. it is not waterproof unlike the other chargers, they were like keep it around 8 amps max or less and voltage whatever but total couldn't be more than 250 watts or something.

so any size solar panel or voltage or watts is cool...just keep it to total of 250 watts...only had one input for solar panel, (in case you wanted to use it later for a shed or something adding more panels etc or generator )

http://www.amazon.com/YEKE-AdjustableHigh-converter-regulator-voltmeter/dp/B00MUTLTZE/ref=sr_1_6?s=electronics&ie=UTF8&qid=1414509999&sr=1-6

boost convertor with led votage reading...input 10-30 volts 8 amps output up to 46 volts 4 amps....90 watts output without adding heat sink. 20 bucks...

the only thing does it charge it up the battery when the panel goes inbetween clouds.. I believe this has been a constant issue with all the buck convertors on this thing....works good then clouds come and then system shuts off....so you have to restart your charger again... the output led is nice so you see the volts and if your at 36 volts output not a lot of amps to blow up your battery I guese with a 100 watt panel