SOLARPAD Open Source 5 Watt Smart Phone Solar USB Charger
SOLARPAD Open Source 5 Watt Smart Phone Solar USB Charger
Strap this water-resistant solar panel and battery to backpacks or mount it to tripods for camping, hiking, and cycling. MADE IN USA
Strap this water-resistant solar panel and battery to backpacks or mount it to tripods for camping, hiking, and cycling. MADE IN USA Read more
About this project
"Independent Power." NOW OPEN SOURCE! Our Solarpad Kit sets a new standard for a rugged, lightweight, compact, powerful, water resistant, and easy-to-use USB solar charger that can keep a smart phone charged all day! Connect Solarpad to the Power Core battery input then use the cable that came with your smart phone and plug it in to the Power Core output. Solar charge the Power Core battery and charge your phone from this battery at the same time! We designed the Solarpad Kit without an on/off button so you just plug it in and it works automatically! If a phone has a unique connector, one end of its charge cable always has a standard USB compatible plug. No extra cables are required because they are built-in. Use the Solarpad Kit on your next adventure! Will not leave you powerless. Free instructions and files for this project can be obtained from www.solarcyclepower.com
* Those interested in custom orders, like pledging extra for multiple batteries or panels, please message me so I can make a note of what you want. Thanks!
What About Other Similar Solar Chargers on the Market?
Click below for an animation comparing the Solarpad Kit vs. Competitors
The Solarpad Kit is designed to outlive the life of your Smart Phone! Solarpad uses a high-quality, custom Suntactics solar panel, which has a fluoropolymer film with the best light transmission, precision cut and tabbed high-efficiency solar cells, and a high-strength substrate. The panel is attached to an aluminum housing, which holds the buckle straps and 1/4-20 tripod thread in place and acts as a passive heat sink to cool the panel. Our Power Core battery uses a high-efficiency, high-power charge controller from Maxim and the housing is sealed with high-strength epoxy, which prevents water from leaking in. Also, Power Core uses the same battery that's used in the Tesla electric car, which is the best battery of its kind. Even the built-in USB cables consist of thicker gage wire, which allows the electricity to flow more efficiently. The Solarpad Kit is engineered to squeeze the most energy possible from the sun's rays in to your smart phone. No short-cuts that compromise power or efficiency are taken, period. A fully charged Power Core will recharge a dead iPhone from 0% to 100% in 3 hours even after being unused for a month! Our competitors may have a power level indicator, but for this size solar charger, power level indicators are inaccurate and not very useful. Other similar sized solar chargers can only charge a Smart Phone from 0% to 70% and take over 4 hours to recharge, so what good is a power level indicator if it won't charge your phone from 0% to 100% at any level? Power Core's Green LED lights up when charging and turns off when fully charged. Much larger smart phones, like the Samsung Galaxy S4, have a battery that's twice the size of an iPhone battery, but a fully charged Power Core can still provide a Galaxy S4 a 0% to 70% charge.
Why Open Source Hardware?
The solar USB charging market has become saturated with low-quality and poor performing products and every year the big companies are selling the same products with very little improvement. Therefore, Solarcycle has developed its open source solar USB charger to empower customers with the ability to build their own solar USB chargers and to prove that a better solar charger that outperforms anything else on the market is possible. Click here for instructions on how to build the Solarpad Kit.
Solarpad Solar Panel Specs (Made in USA):
* Size: W 6.5 inches X L 10.9 inches X H 0.6 inches
* Strap Material: Polypropylene * Strap Length: 1.5 Feet
* Fastener Style: Plastic Side Release Buckle
* Cable Length: 10.0 inches * Weight: 270g (9.52 oz)
* Body Material: Anodized Aluminum with Nylon Trim
* Output - Female USB 2.0 Type A Connector
* Nominal Output - Current: 1000mA | Voltage: 5 Volts
* Max Open Circuit Voltage: 6 Volts
* Cell Type: Monocrystalline * Cell Efficiency: 18.8%
* Compatible with Power Core Battery Only
Power Core USB Battery Specs (Made in USA):
* Time to Fully Charge Power Core @ 5V 1A: 3 hours
* Capacity: 3350mAh/3.6V * Type: 18650 Lithium-Ion
* Diameter: 1.2 inches * Body Length: 4.2 inches
* Cable Length: 7.0 inches * Weight: 100g (3.53 oz)
* Input - Male USB 2.0 Type A Connector
* Input - Current: 450 to 1300mA | Voltage: 5 to 6 Volts
* Output - Female USB 2.0 Type A Connector
* Output - Current: 500mA | Voltage: 5 Volts
* Body Material: Aluminum Tube with Rubber Caps
* Battery Life Under Typical Use: 5 years
* Provides up to 140% iPhone Charge or 70% Galaxy S4 Charge
* Compatible with iPhone, Android, Windows Phone, and Others
* Many other uses shown below:
Where Do the Funds Go and How Long Will it Take to Finish?
Solarcycle is here to meet your USB charging needs for the outdoors! We've solved the fundamental problems with solar USB charging, but right now each Solarpad Kit is assembled by me in my apartment using rapid prototype components. In order to build the final production version at a reasonable cost, funds must be raised to purchase a minimum order of hundreds of solar panels, batteries, cables, brackets, tubes, circuits, and plastic components. Other equipment costs include molds for the plastic parts and creating custom assembly fixtures. The Solarpad Kit is designed be as simple to manufacture as possible and it is always being refined for the most efficient assembly. Our suppliers have given us great quality prototype parts and they are ready to manufacture the components in larger quantities. Typical manufacturing lead-times for components are about 30 days and test batches are always ordered before going in to large-scale production. Tools, fixtures, test equipment, and work benches for assembling products need to be purchased too. On top of that, there are a lot of house-keeping duties like business licenses, permits, and bookkeeping that any new start-up has to take care of. Realistically, it should take about 6 months to set-up shop, order parts, manufacture parts, inspect components, assemble each batch, final test each unit, package, and then ship them.
FCC Compliance: NOT required because circuit frequencies are below 1.7MHz
- Do Not connect Solarpad directly to a Smart Phone. Solarpad outputs up to 6 Volts of raw unregulated solar power that may not be compatible with Smart Phones. Only connect Solarpad to Power Core.
- Do Not leave Power Core or your phone in direct sunlight. Keep them covered or in the shade. The USB cables allow Power Core to be connected to Solarpad while being hidden away from direct sunlight. Some competitor solar products have a built-in battery that is permanently attached to the solar panel itself, but heat from the solar panel can cause the charge circuit and battery to get very hot, stop charging, degrade the battery, and shorten its lifespan.
- Modifying: Never attempt to repair or modify the Solarpad Kit yourself. The Solarpad Kit does not contain any user-serviceable parts. Disassembling the Solarpad Kit may cause damage.
- Acceptable Temperatures: The Solarpad Kit is designed to be operated in temperatures between 0º and 45º C (32º and 149º F).
- For best results, fully charge Power Core before traveling.
- Keep USB Connectors Dry: If the USB connectors get wet, dry them off. They are water-resistant, but the metal USB connectors may rust with long exposure to moisture. Shake and blow out moisture inside the connector.
- Storage: Store the Solarpad Kit in room temperature. Power Core should be recharged about once a year to prevent over discharge.
Don't Let Your Next Outdoor Adventure Look Like This!
Risks and challenges
I have a M.S. in Mechanical Engineering with over seven years of experience in the semiconductor industry. I also gained a lot manufacturing experience working at my Dad's sheet metal shop since I was a kid. I have spent the last 3 years designing and testing portable energy systems for smart phones and used them while on bicycle tours, camping, and hiking. The prototypes have already been designed with manufacturability in mind, which include designs for plastic molds. From my experience with complex project deadlines, a 6 month lead-time is reasonable for this type of project with the resources available. Unforeseen issues that can delay the shipment of rewards to Kickstarter backers include, but are not limited to:
* Delays in receiving components on time from vendors.
* Delays from rejected parts during inspection.
* Delays from the carrier in shipping the product to the Kickstarter backer.
These products are designed to last many years and they won't ship unless they've been fully qualified and tested. Backers that receive a factory defective item can send it back to us right away and we'll exchange it for a new one. As a backer of other projects, I understand the importance of honest communication, even if the news is not so good, so I will make it a priority to answer all backer questions as fast as I can and give updates as soon as possible. We are on this journey together.Learn about accountability on Kickstarter
Protecting any bicycle or backpack accessory is always a matter of judgement. For commuting, after you lock up your bicycle, the Solarpad Kit can be detached and you can take it with you to charge your USB devices away from the bicycle. If your bicycle is kept in a secure outdoor bicycle facility (like Bike Valet Parking or in front of your work with security cameras), then the Solarpad Kit can be left outside to charge the battery in the sun. While camping, hiking, or on long distance touring rides, it is less of an issue because for the most part, your bicycle or backpack is with you and/or with your friends at all times.
I used to own an electric bike, so I have experience in this issue. The Solarpad Kit produces 5 Watts and the minimum power for an electric bike motor is between 100 and 200 Watts. That means that it would take over 40 days to store enough energy to ride an electric bike for only 1 hour! I noticed that hardly any electric bikes have a USB port for charging phones, so you may still want to use the Solarpad Kit on an electric bike. However, European electric bikes, like the Smart bike, are starting to have built-in USB ports. That said, it would take a large solar panel array, probably 6ft x 6ft, to power an electric bike for daily use.
Future products will be Tablet compatible. However, for now, Power Core can charge black & white e-readers and might be able to partially charge some tablets, but it's not designed for charging tablets. Our standard is to make battery products that can charge a USB mobile device from 0% to 100% off a single charge. A USB battery at least 4 to 8 times the size of the Power Core is required to fully charge tablets from 0% to 100% off a single charge, so for now we are only making an external battery for phones and other small devices with a similar battery capacity. If other similar sized USB batteries on the market claim to charge a tablet, they will only charge a tablet from 0% to about 20%.
Lithium-Ion batteries have the highest power and capacity for the smallest size. NiMH batteries have lower power and capacity for the same size. The Lithium-Ion battery we use in the Power Core is the only battery for this size with a confirmed 3350Ah/3.6V capacity and voltage on the market. This wikipedia link here shows that the voltage of a NiMH battery is 1.2 V where a fully charged Li-Ion battery is 4.2 Volts. You would need to connect at least 4 fully charged NiMH batteries together to match the same voltage as one fully charged Li-Ion battery.
The solar cells have been incased in plastic making it a very strong composite material. The battery is housed in an aluminum tube with epoxy sealed rubber caps for shock and water resistance. Solarpad and Power Core can be dropped, hit, and submerged in water without breaking it. By following the Safety and Troubleshooting precautions, it should last its intended lifespan without any issues under normal outdoor wear and tear. A carrying case is not required to protect the Solarpad Kit.
Lithium-Ion battery life is determined by the point at which the capacity starts to significantly deteriorate. Power Core is designed to last 5 years under normal use without any large drop in capacity. It will still work after 5 years, but not hold as much charge. However, even if it loses 50% of its original capacity after 5 years, it will still work better than any similar sized USB battery on the market today.
Talk time is irrelevant when it comes to smart phones. Just leaving the smart phone screen on doing nothing will drain the battery fast! The chip for making calls takes very little energy. Most of the energy is used up by the screen, operating system, video streaming, playing games, and surfing the web. When competitors talk about talk time, they are assuming that the screen takes up no energy, which is ridiculous! We really should be talking about screen time instead. The Solarpad Kit can charge an iPhone up to 100% in 3 hours so you can do whatever you want with your phone.
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