Solar Powered Cell Phone Charger

Step 5

Once this is done, place all the wires into the box and place the top on. Velcro the solar cell to the top of the box. And lastly screw the top of the box down.

I had to wait 2 days before the sun came out, but it was worth the wait. It charged my phone right up!

Comments

[SpeakNoEvil]

Great device! I'm curious about the input voltage from the solar panel - did you have to match it to the car charger or the phone?

[kenshi07]

I would guess that the car charger device would regulate the voltage for him.

[Knuxz]

Incorrect. The car port is just that. A port. All it does is allow power to flow through it to the charging device. It, itself is not electronic in any way, except having power flow through it.

Example:
If you have twenty-four instead of twelve watts run to it, it will output at twenty-four, not twelve.

[lloydrmc]

Incorrect. The car charger itself has voltage regulation circuitry in it.

[Pale_Flyer]

kenshi, there still needs to be enough power for the charger to knock it down to the correct level

knuxz the PORT is just a contact, as you stated. there is nothing else there.

lloydrmc, you are right in the charger, but technically Knuxz is also right, as he specified the PORT, not the CHARGER. the charger would be expecting 12V at like 10 Watts (i am not sure on the wattage, if i am wrong, i appologize) the charger probably has a transformer in it set to about 2.4:1, so if 6 volts go in, you will not have the 5V the phone is expecting, or what every the phone wants. i am going off current phones which normally go straight from USB at 5V.

[Pale_Flyer]

with the system he designed, he could connect anything under 6v to it. as currently configured, he has to have it as a car style plug... if he spliced in another power port, say to screw terminals, or aligator clips, he could direct charge just about anything, and maybe use the terminals for a battery, with diodes so the panel could charge the battery, and the battery could power the port. WARNING! WARNING! WITH OUT VOLTAGE REGULATOR ON BATTERY RISK OF FIRE, EXPLOSION, DEATH! Some capacitors in a bank with some resistors and diodes may work better, and through a friends, ahem... experimentation... ahem... in electronics class... caps don't appear to suffer from overcharge problems... he plugged some 2000 mA caps into breadboard power supply at much greater than recommended voltage/amperage, and they did not suffer problems after multiple charge/discharge cycles. i know small caps can power small circuits depending on drain for at least a few seconds. So with the right circuit, and the right cap(s) you could build this with a decent "charge" capacity. and ultracaps would be even better, but have not seen any other than online.

[lloydrmc]

2000mA, or uF? I'm not aware that caps have an amp rating at all.

Look - this would make a LOT more sense with more/better solar cells, and some NiCD or NiMH batteries to store the juice. Set it up so you have nor more than C/10 or maybe C/5 at about the correct voltage, in optimum sun conditions, and you will be fine.

"C" is the capacity of the battery. So, with 3000mAh AA batteries (which are available cheap as dirt on ebay), you set it up so you have no more than 300 to maybe 600 mA output from the solar cells.

You'll note that the specified solar cell has a current rating much lower than that. No problem, except that it would take proportionately longer to charge any given battery. It would also help to orient the solar cell properly, at the correct heading and angle (rather than have it just sit flat on top of the box.

I'm pretty sure someone has a solar-assisted minty-boost project on Instructables..

[Pale_Flyer]

that was supposed to be Farads in my comment... i wonder how i messed that up...

i looked at your comment, and yeah, you could go for a battery bank, but that would as you said, take a while to charge. The other thing is, i think i was suggesting more along the lines of smoothing the charge, or maybe a quick emergency charge, like 5-10% of a cell phone batt to allow for a call to a tow truck... i am not 100% sure, as it has been over a year and a half since i have looked at that.

[gabe009]

The only time i would use this is if I'm stranded on a island.

[rjwarpath]

I made something like this once for a middle school science fair project. At the time it was used to power a Walkman. The one that I created had 2 rechargeable batteries inside the the case. A power cord then went to the AC jack on the Walkman. It basically gave me about 30mins of extra play time. Rechargeable batteries and solar cells are much better now than they were 15yrs ago. I'm sure the results would be better now. May have to try this project with a few innovations. Good instructable!

[christian2gothic]

why not bypass the car charger completely and just stick the solar panel to the back of your phone with a voltage regulator and wire going straight to your phone jack/ in your phone, so your phone just have to have it's back facing light to stay charged???
is there a way to make that happen and still be compact and sleek?

[hugoepifanio]

 hi, i think this is what you're looking for:

www.instructables.com/id/A_SOLAR_POWERED_MOBILE_PHONE/

Have fun!

[creaton20]

what happens to the energy your solar cell collects once your cell phone is fully charged, could you connect some kind of battery to store that for later use and how would you do that