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Improving draw current from smartphone?

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Dominover

New Member
Short explanation:
When I charge my phone via a usb charger you plug into the power point, by measuring the output voltage and draw current, it shows around 5.2 volts 1.5 Amps. So the phone is drawing around 1.5 Amps.

When I used a hand cranked charger (portable charger) the output is 5.4 volts with .5 Amps draw current from the phone.
So I tested the portable charger (hand cranked) and it seems that I can get as much as 5.5 volts 3 Amps from it consistently.

From what I'm told, this is because the phone queries the charger and tells it how much draw current there should be. Unfortunately, the phone can't communicate with the hand cranked charger so the draw current remains low at .5 Amps.

I was told to bridge the positive and negative terminals of my charger output cord with a 1000uf to 47000uf capacitor. But I'm not sure what this will do. I can't seem to find the person who told me this so I'm asking does anyone know why this would work and if there are any other solutions to my problem?

Thanks
 

tcmtech

Banned
Most Helpful Member
Unless your power source has the necessary communications circuit or whatever your particular phone uses to identify a power sources current capacity, just adding capacitors wont do anything.
 

JonSea

Well-Known Member
Most Helpful Member
iPhones determine the maximum current they may draw by voltages on the data lines. Four resistors will tell the phone what current it may draw.

I wrote an article on Digital-DIY listing some possibilities. I will provide a link shortly.
 

JonSea

Well-Known Member
Most Helpful Member
Android use a different system. I haven't tested this out, but I have read that either a 100 ohm resistor or a short tying the data lines together will allow an Android device to charge at high rate.

USB-C and high-rate charging using >5 volts do depend on communications between the device and charger to use higher voltages.
 

dr pepper

Well-Known Member
Most Helpful Member
Yes I heard something similar, if you short the middle 2 data connections on the Usb connector the device will change at 1000mA.
 

Ramussons

Active Member
Would'nt the battery being charged heat up if the charging current is increased? Maybe the "Battery Exploding" news is because of this?

I remember reading about this danger regarding using an "original OnePlus x USB3 cables" on other phones.
 
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JonSea

Well-Known Member
Most Helpful Member
Would'nt the battery being charged heat up if the charging current is increased? Maybe the "Battery Exploding" news is because of this?

I remember reading about this danger regarding using an "original OnePlus x USB3 cables" on other phones.

No. The phone or other USB device will only use the current it's designed for. The voltages on the data pins (for iDevices) or resistor/short (for (most?) Android devices) just tell the device that it may draw more power if it likes.


Here it is.. Found a video on this on YouTube just as you were saying.
Note rhat this video will only work for (most?) Android devices. It's a little more complicated fot iPhones as I have shown above.
 

Dominover

New Member
It's a great hack if it works! I'm yet to try it.
I bought a folding solar panel charger some time ago and was never really impressed by the 5.4 volt .5 Amp output to the phone. I thought this was just the fact that the panel was rubbish and have rubbished all of them since.

Now I realize that it's the phone drawing the current and will regulate it if it can't communicate with it. So with this hack I may have something useful after all.

My friend sold his Goal Zero folding solar panel for the reason I stated above. He's going to be cranky when I tell him about this.
 

MikeMl

Well-Known Member
Most Helpful Member
5V @ 2.5A = 12.5W, so the panel should be capable of 13 or more Watts.

Are you saying that a product like this doesn't do what is advertised?
 
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Dominover

New Member
Well yes and no. The product is probably capable of over one Amp output but your phone may not let you use it all.
I was quiet disappointed with the output of these panels.
A friend of mine has an Ankar solar charger and he wasn't too impressed with their ability to charge a phone either.
It could be because the phone restricts the output to only .5 Amps when it may be capable of more.
 

MikeMl

Well-Known Member
Most Helpful Member
When a charger says this:

Fast Charging Technology: PowerIQ delivers the fastest possible charging speed up to 2.4 amps per port or 3 amps overall under direct sunlight. 21 watt SunPower solar array is 21.5-23.5% efficient, providing enough power to charge two devices simultaneously.


And it claims to work with this list of products:

Solar for iPhone 7 / 6s / Plus, iPad Pro / Air 2 / mini, Galaxy S7 / S6 / Edge / Plus, Note 5 / 4, LG, Nexus, HTC and More

I take that to mean that they have figured out how to trick the respective phones into accepting the higher charge rate. I have bought non-Apple automotive chargers for my IPad, and those third parties figured out how to get the IPad to charge at the highest rate...
 

Dominover

New Member
They could have.. But keep in mind that the output they advertise are under certain test conditions, probably using some artificial high intensity UV light. I do have a really large solar panel here and it works allot better than those small fold out ones.

Seriously, without some special mod to communicate with the phone or ipad, I can't see any of these panels putting out more than .5 Amp.

There's plenty of people on youtube using this method (bridging the data lines in a USB) to speed up the charging speed.
 
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