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I wanted a charger for my iPodTouch and the MintyBoost was definitely my first choice. I wanted to take it a bit further and make it not only rechargeable but also solar powered. The other issue is that the iPhone and iPodTouch have large batteries in them and will deplete the two AA batteries in the MintyBoost rather quickly so I wanted to increase the battery power as well. What I really wanted was a MightyMintyBoost!
Apple has sold over 30 million iPodTouch/iPhone units- imagine charging all of them via solar power.... If every iPhone/iPodTouch sold was fully charged every day (averaging the battery capacity) via solar power instead of fossil fuel power we would save approximately 50.644gWh of energy, roughly equivalent to 75,965,625 lbs. of CO2 in the atmosphere per year. Granted that's a best case scenario (assuming you can get enough sunlight per day and approximately 1.5 lbs. CO2 produced per kWh used.) Of course, that doesn't even figure in all the other iPods, cell phones, PDAs, microcontrollers (I use it to power my Arduino projects) and other USB devices that can be powered by this charger- one little solar cell charger may not seem like it can make a difference but add all those millions of devices together and that's a lot of energy!
There are some really nice features about this charger:
It's solar powered!
It's small.
Large battery capacity- 3.7v @2000mAh
On board charger charges via solar, USB or wall wart. Accepts input power from 3.7v to 7v.
Remove the solar cell after charging and you have a nice compact USB power supply.
Unplug the solar cell and use the Velcro to secure the MightyMintyBoost inside a backpack or messenger bag- now plug in a larger solar cell attached to your bag for even faster charging. Using a slightly larger solar cell (6v/250mAh) you can generate enough power to fully charge an iPhone in about 5.5 hours and an iPod Touch in 4 hours.
Building this is really easy and straightforward- it only took me around an hour so follow along and build one for yourself!
Safety note and general disclaimer: Be careful cutting the Altoids tin as it can have some really sharp edges- file them smooth if necessary. Assemble this at your own risk- while it is really easy to build, if you mess something up there is the potential to damage the electronic device you are trying to charge. Be careful in your assembly and soldering work and follow good safety practices. Only use a type of battery charger specifically designed for the type of battery you are using. Please read through the entire Instructable before asking questions- if there are are any questions just ask and I'll help out as best as I can!
Apple has sold over 30 million iPodTouch/iPhone units- imagine charging all of them via solar power.... If every iPhone/iPodTouch sold was fully charged every day (averaging the battery capacity) via solar power instead of fossil fuel power we would save approximately 50.644gWh of energy, roughly equivalent to 75,965,625 lbs. of CO2 in the atmosphere per year. Granted that's a best case scenario (assuming you can get enough sunlight per day and approximately 1.5 lbs. CO2 produced per kWh used.) Of course, that doesn't even figure in all the other iPods, cell phones, PDAs, microcontrollers (I use it to power my Arduino projects) and other USB devices that can be powered by this charger- one little solar cell charger may not seem like it can make a difference but add all those millions of devices together and that's a lot of energy!
There are some really nice features about this charger:
It's solar powered!
It's small.
Large battery capacity- 3.7v @2000mAh
On board charger charges via solar, USB or wall wart. Accepts input power from 3.7v to 7v.
Remove the solar cell after charging and you have a nice compact USB power supply.
Unplug the solar cell and use the Velcro to secure the MightyMintyBoost inside a backpack or messenger bag- now plug in a larger solar cell attached to your bag for even faster charging. Using a slightly larger solar cell (6v/250mAh) you can generate enough power to fully charge an iPhone in about 5.5 hours and an iPod Touch in 4 hours.
Building this is really easy and straightforward- it only took me around an hour so follow along and build one for yourself!
Safety note and general disclaimer: Be careful cutting the Altoids tin as it can have some really sharp edges- file them smooth if necessary. Assemble this at your own risk- while it is really easy to build, if you mess something up there is the potential to damage the electronic device you are trying to charge. Be careful in your assembly and soldering work and follow good safety practices. Only use a type of battery charger specifically designed for the type of battery you are using. Please read through the entire Instructable before asking questions- if there are are any questions just ask and I'll help out as best as I can!
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Signing UpStep 1Tools and materials
Here's what you'll need to build your own MightyMintyBoost:
Tools:
Soldering iron
Scissors
Wire cutters
Pliers (or muiltitool)
Multimeter
Metal shears
Clear packing tape
Materials:
MintyBoost kit
Lithium polymer battery charger (the original one specified was discontinued)
3.7v 2000mAh Lithium Polymer battery
JST connector/wire
Small solar cell
2" x 3" adhesive backed Velcro
Small double sided adhesive squares
Altoids tin
7/10/10 UPDATE: Adafruit now also sells all the parts you need to make this a bit more mighty. Have a look here!
http://www.adafruit.com/blog/2010/07/09/how-to-make-a-solar-mintyboost-a-solar-power-charger-for-your-gadgets/
7/18/11- ANOTHER UPDATE: Adafruit recently introduced a new LiPo charger that is specifically designed for solar charging that has much better performance. It's not as small but the performance gains would make it worth it. Have a look and read about the design here-
https://www.adafruit.com/products/390
Some notes:
The single cell Lithium Polymer charger can accept input power that ranges from 3.7 to 7v maximum. When the cell reaches full charge the charger will automatically switch to trickle charging. When charging using the mini USB port, the charging current is limited to 100mA. When charging using the barrel plug jack, the charging current is limited to 280mA.
The solar cell maxes out at approximately 5v @ 100mA in bright sunlight. If you need faster charging simply use a larger solar cell- a 6v cell @ 250mA would work very well and they are easily obtainable and inexpensive. I used the size of solar cell that I did because I wanted it to be super compact.
I could not find out from the manufacturer if the solar cell I used has a blocking diode. A blocking diode is used in many solar charging systems to prevent the solar cell from draining the battery during low light conditions. Instructables member RBecho pointed out that the charging circuit used negates the need for a blocking diode in this application. You can tell when the solar cell is producing enough power because the little red LED on the charger will come on during charging.
Tools:
Soldering iron
Scissors
Wire cutters
Pliers (or muiltitool)
Multimeter
Metal shears
Clear packing tape
Materials:
MintyBoost kit
Lithium polymer battery charger (the original one specified was discontinued)
3.7v 2000mAh Lithium Polymer battery
JST connector/wire
Small solar cell
2" x 3" adhesive backed Velcro
Small double sided adhesive squares
Altoids tin
7/10/10 UPDATE: Adafruit now also sells all the parts you need to make this a bit more mighty. Have a look here!
http://www.adafruit.com/blog/2010/07/09/how-to-make-a-solar-mintyboost-a-solar-power-charger-for-your-gadgets/
7/18/11- ANOTHER UPDATE: Adafruit recently introduced a new LiPo charger that is specifically designed for solar charging that has much better performance. It's not as small but the performance gains would make it worth it. Have a look and read about the design here-
https://www.adafruit.com/products/390
Some notes:
The single cell Lithium Polymer charger can accept input power that ranges from 3.7 to 7v maximum. When the cell reaches full charge the charger will automatically switch to trickle charging. When charging using the mini USB port, the charging current is limited to 100mA. When charging using the barrel plug jack, the charging current is limited to 280mA.
The solar cell maxes out at approximately 5v @ 100mA in bright sunlight. If you need faster charging simply use a larger solar cell- a 6v cell @ 250mA would work very well and they are easily obtainable and inexpensive. I used the size of solar cell that I did because I wanted it to be super compact.
I could not find out from the manufacturer if the solar cell I used has a blocking diode. A blocking diode is used in many solar charging systems to prevent the solar cell from draining the battery during low light conditions. Instructables member RBecho pointed out that the charging circuit used negates the need for a blocking diode in this application. You can tell when the solar cell is producing enough power because the little red LED on the charger will come on during charging.
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I plan on building a 12V system for other power hungry applications, but instead of a flimsy altoids can, i decided to beef it up a bit with a pelican project box. If anyone has any suggestions about how to cover ports a little better, that would be great.
Check it out!
Love the instructable! Great work.
Could I just leave out the middle man and solder th solar panel wires straight to the lipo battery to charge it?
one more thing, you said that the charging circuit used doesn't require a blocking diode. Since that model was discontinued, does the other one listed require a diode? ( http://www.sparkfun.com/products/10161 )
Thanks in advance.
The best way to connect the solar cell would be to connect a mini USB cable to the solar cell and then plug the cable into the board. There is a guide here that shows how to splice a mini USB cable to a solar cell.
http://ladyada.net/make/solarlipo/
Just wanted to say this was an awesome project and a great gift idea for my girlfriend! Being that she drives around a lot it is comforting to know that if she ever breaks down she'll have a charged phone ready to call somebody to get some help!
First and foremost I am a complete rookie for these kind of things and I am still riding the learning curve, so exuse my questions if they seem ridiculous.
So I built this about a month ago and it worked very well!
However I would like to try and improve on my previous attempt, add a pelican case, a larger solar cell, larger LiPo battery.. I'm just looking for some clarification on a few things if you could give me a hand.
1. If I upgrade to the 6v 2 watt solar cell, will the battery charge faster?
2. Will I need to upgrade to the 2200 mah battery to charge faster as well?
Essentially I am just looking to charge faster than the current 3.7-3.9 volts I am currently getting from my first charger without crossing over the 7v threshold/without needing to make it anymore confusing for myself.. If you could break it down for me into elementary terms, that would be awesome! I looked through the comments section and abused google and could not quite get a grip on what I would have to do to complete this myself.. I appreciate your time in making this article and your support with my question.
To answer your questions-
1. Yes, the 6V 2 watt panel will charge the battery faster. That should put out close to 300mA so it would charge almost three times faster than the 5V 100mA solar panel.
2. A larger battery will not charge faster- it will charge slower than a smaller capacity battery. It's like filling a swimming pool with water- the bigger the pool the greater amount of time it takes to fill it. The flip side to this is the larger battery will run for a longer period of time simply because it holds more juice.
If you have any other questions just let me know!
Just one more if you wouldn't mind, if I do use that 6v 2watt panel, would I have to make any other changes? Such as use a different LiPo charger? Or will it work exactly the same as if I were going to use the smaller cell?
Thanks again Honus!
Adding the circuit below can solve the problem.. maybe, anyone got some idea? circuit copied from:
http://www.simple-electronics.com/2011/09/iphone-charger-circuit.html