DIY Solar Panel Handphone Charger not working

Great thanks for the information.I just like the fact there is experimenting going on.

[inetdog]

One problem for DIYers who are not up to speed on the theory and technology is that thin film devices can look like a single "cell" but actually consist of multiple cells in series on a single substrate.

We generally would call them small thin film panels rather than thin film cells.

When looking at silicon based crystalline cells one cell will produce an output voltage of about .5V. No more, no less.

If you have two identical solar light panels (not cells!) you can wire them in series to get twice the voltage, allowing you to charge a higher voltage battery.

Note also that some solar lights use lithium chemistry batteries (often LiFePO4) which take on the order of 4V to charge, while others use Nickel Metal Hydride (NiMH) batteries which only need 1.5V to charge. (3.0V if two batteries in series)

could try cutting solar cells to get more voltage. LOL
im very clueless man sorry

[Nakamaru]

sorry, what i was saying is
i got 250mA+ reading from my multimeter

but why my battery doctor only detects 50mA from the small solar panel while charging ?
and why does the voltage drop to 3.7v while charging ?

Im confused what you are trying to do.

That solar charging chip requires 0.9 - 5volts
and 500-600ma

sorry forgot to put in .10 amps. :P

[Nakamaru]

so... in conclusion, both of our DIY solar panel is not 250 mA and we've been lied by the store
i used a solar charging chip for the c60 panel

2pcs C-60 Cells will not produce enough Voltage for the cell phone you are trying to charge. My cell phone requires 3.7 Volt. So I would try finding a Solar cell that produces 5 Volts.

Ive got a large glass solar cell from solar garden lights. This one produces 4 volts and .10amps. and powers my cell phone which is 3.7 volt...

[Nakamaru]

okay i might have found the problem here.

yesterday, i bought a handy dandy charger doctor https://www.adafruit.com/product/1852 and it showed some interesting result.
here's the results of both of my PV chargers.
2 Maxeon 0.5V 6A in series (not charging) 4.7 V & 0 A
2 Maxeon 0.5V 6A in series (charging) 4.1 V & (0.05 A Max)

1 Mini solar panel 5V 220mA(not charging) 5.2 V & 0 A
1 Mini solar panel 5V 220mA(charging) 3.7 V & (0.07A Max)

1 A AC Charger (not charging) 5 V & 0 A
1 A AC Charger (charging) 5 V & 1 A

so, is it because my mini solar panel is NOT actually 250mA+ ? (the reading i got from my multimeter)
or what here ?
i'm really confused.

[Nakamaru]

well, you see the chip back at the PV cells ?
they're the voltage booster charger circuit.
and im buying a schottky diode (very low voltage drop i believe) and it should arrive today.

[Mike90250]

Not going to work, ever.

The PV cells are 0.5V, you have 2 in series, which would give you 1.0V That is not going to charge a 4.7V battery, unless you use a voltage boost charger circuit. Adding a diode will reduce the voltage by about 0.7V

[Nakamaru]

i'm back after like 1 weeks or more.

i bought some new panels, this time i bought a good panel (i think)
it's maxeon c60 3.2 W 0.5 V 6.4 A
i serial'd both of them and soldered them to my usb charger chip.

i thought that this is gonna work at first, but unfortunately it didn't charge.
maybe it is because i didn't place a diode ? (my diode is still shipping so i'll have to wait)
i tested it with my multimeter and it showed 4.8V and 250ma+

and i downloaded DU battery saver and saw a difference


Screenshot_2016-06-08-15-52-09.png
this is charging with usb to my laptop
Screenshot_2016-06-08-15-52-20.png
this is charging to my new solar panel (i got the same screenshot with the old panel)
did you notice the battery logo is charging ? (upper right)

oh, and also this is my new panel
WIN_20160608_161717.JPG WIN_20160608_161729.JPG

Im happy you got it working atleast. I got mine to work thanks to you!
The plus and negative on the backside sure are confusing.

So now your problem is you not charging Fast Enough. I think getting another solar cell in parallel may help bit more!

If you can reach anything closer to 5V and 600ma
you should have a better Charging

HAha thats funny. I ran it parallel and it works also! Thanks I would have never clued in that it needed to be parallel

[SunEagle]

well, i don't use any resistors on the circuit so it should be the lowest resistance.
or i don't know... im really clueless in this resistance thing.

Every solder point or wire connection adds resistance to the circuit. A poor connection may cause a large increase of resistance thus lowering your amp output.