Im looking at making a self build iPad solar panel charger, Is it possible to get a small solar panel, a battery to hold charge and then a USB output? nothing fancy, just power in and power out?
Lithium okorder / For USB power, there are some references you should seek out from the websites of Fairchild, On Semiconductor, Texas Instruments, National Semiconductor, just to name a few. There are others, and if your IPad has the control circuitry for the accurate charging of their batteries, and you just need the USB port to have the right power available, a high compliance regulator such as an LM7805 should do just fine. Spec sheets for that regulator are available through the above mentioned manufacturers websites as well.
You would need a pretty hefty panel, the standard power charger is like 0 watts. You would need more than that for the overhead of charging a battery and converter loss. You would need a regulated supply, like a car ipad adapter, I seen them for like 20 bucks. They have to say Ipad , the ipod/iphone chargers have less power and would charge much slower.
Sure it is possible. There are even commercial products that do that. I have a solar cell phone charger. But it is not able to fully charge the phone battery. I am not sure why but I suspect the voltage it puts out is too low. In other words, it is a poor design. It is certainly possible to make a better design, but maybe not easy. You can damage a battery by over charging it, so just increasing the voltage is not the solution. You need just the right voltage and current.
Yes you can. You would need to look up and see the voltage output by a USB port and the current rating. You should be able to find it on the web. I have found it in the past. Check several sites to make sure that you have the correct values. Then wire up the solar panels to get the correct voltage and current capabilities. You may need to learn how a LM7805 works and wire one of them up to the circuit if you can't wire the solar panels to get the correct voltage. Make sure that you protect the solar panels from the weather and have some kind of protection for your iPad so that it does not get rained on and ruined.
