DIY Solar Panel Handphone Charger not working

[Nakamaru]

i used it to charge my samsung galaxy ace 3 which i think is kinda a small phone. the guy from the store said that the panel could produce 5v and 220ma. but, when i measured it with my multi meter it showed 5v and an amperage over 250 ma (my multimeter can only measure up to 250ma :') i think 5v and 250ma+ should be enough to charge my phone no ?

[Guest]

you measured it in the sun? If there is no sun out it wont have enough amps to charge the phone

Im not sure why it wont charge. Other than that chip dont have MPPT

also did you try doing this also without the battery?

I just tested it out with same panel and same chip as you. And It didnt seem to work at all. I used my tiny MPPT chip and sure enough it works with same panel as yours.

This 5volt small panel seems to be drawing electricity out of the cell phone. And its in full sunlight. 5Volt is obviously not enough if Im loosing charge.

[Nakamaru]

well, the panel won't try to draw electricity if i use diode right ? oh and i tried this very simple design as well and my phone keeps getting charged then not getting charged (im not sure how to say that in english lol) I used a randomly-found-sk34 diode
20160515_220413.jpg

[Nakamaru]

oh and GoldCobra, would you mind to send us some pictures about your project ?

[Guest]

I tested this without a Diode. So I can see if there is any power being loss. Which there is. Pretty sure were using the same epoxy panel.

I tried both chips. My Solar Charger MPPT type. And the chip you have. Which is identical.

That said I couldnt get any charge even with my MPPT Chip. Even if I did put a Diode it most likely wouldnt work. I watched my cell phone as the battery would not charge for over 20 minutes

I do believe you may need a bigger solar panel like this one http://www.ebay.com/itm/2W-6V-USB-Mi...YAAMXQlgtS-wsK

I have one of these and they charge my phone up maybe 10-20percent in 1 hr. in full sunlight

You need alot of Volt and amp to charge a phone.
And ive been reading. Depending on the cell phones battery.. You need to find out how much amp is required for it to start charging.

typically when you buy a battery charger it tells you how much amp is required in order to charge a battery

I read this last night and Im glad I did becuase this is new information to me. Read this for little more info
http://www.learningaboutelectronics....th-solar-cells

Also I should advise you shouldnt solder batteries like that, if you must you should get a case for it
you can find cases here for cheap http://www.ebay.com/itm/5pcs-Plastic...0AAOSw~gRVrJVF

[Nakamaru]

well, i cant buy from ebay cause i live somewhere in indonesia.

so... there is a minimum amperage to charge my phone ? that's just... okay...

i have two of the solars so i might try to parallel them.

but can anyone tell exactly the minimum amperage a li-ion battery and a 18650 battery needs ? thanks.

[Nakamaru]

i parallel'd it and got it working, but it charges REALLY REALLY slow. its like 10% in 2 hours. if one panel = 250ma+ then two panels = 500ma+ which is half of my socket charger. why does it charges very slow even it is half of my charger ?

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]

i parallel'd it and got it working, but it charges REALLY REALLY slow. its like 10% in 2 hours. if one panel = 250ma+ then two panels = 500ma+ which is half of my socket charger. why does it charges very slow even it is half of my charger ?

My guess is that you are not really getting 500ma output from those panels for very long even in direct sunlight.

When you have very little to begin with it doesn't take much of any type poor connection to increase the system "losses" and reduce the output significantly.

[Nakamaru]

so... what do i do to make it 500ma+ ?

[SunEagle]

so... what do i do to make it 500ma+ ?

You might have to increase the panel wattage or find a better way to make your wire connections as low in resistance as possible. When you are working with 1/2 an amp and low voltage it is real easy to lose a lot due to just a little extra resistance in the circuit wiring.

[Nakamaru]

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.

[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.

[Guest]

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

[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

[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