So I charged my cellphone with 4x AA Eneloop Batteries in series last night. The current was 424mA, and was charging 1% at roughly 6+ minutes.

The charger made by Anker, can charge the cellphone at roughly the same voltage, but at 1A.

How do create or force current (Amps)?

So a Benchtop power supply can force current threw things.

How can I force current?

I = E/R, I = P/E, I = the square root of P/R

Great. So how is it done?

So obviously, if I had a coil with a resistance of 2.1Ω, and put 4.2vdc threw it, it would glow red, and dissipate 8.4 Watts, allowing 2 Amps or 1.6x10^19 x 2 electrons to pass a given point, per second. That's really great.

So basically, anything after the coil, or resistor in series receives the 2 Amps?

No it doesn't because the device also has a resistance. So whatever the device resistance is, it shares or divides the resistance with the other resistor.

How do you force current onto something?

You increase the voltage to it.

Let's say you have a load with a fixed resistance of 100 ohms and that you have 100 volts across it.

From Ohm's law, I = E/R = 100V/100Ω = 1, so you'd have one ampere of current through the load.

If you increased E to 200 volts, then you'd have I = E/R = 200V/100Ω = 2A, so by doubling the voltage you've forced the current through the load to double.

 

You can use a constant current charger, the voltage will alter automatically as the battery charges up.

 

@Guest3123,

Your phone is very much like you. It doesn't really care about the input, it is going to do its own thing.
Joeyd999 gave you the correct answer early in the thread but your response was simply to blow him off.

The batteries in your phone are being charged by the circuit in your phone. The charger that you need to "modify" is IN YOUR phone.

Your external "chargers" are simply a power source to supply power to the phone's on board charger. As long as they are capable of supplying more power than your phone's internal charger asks for, the charge rate is up to the internal charging circuit. As both the power source and the phone are supposed to comply with USB standards, the input voltage should always be 5.0VDC +/- about 0.2V.

So, if you let this information displace your preconceived ideas, you will research a different question. Your question should be, "How do I get my xxx brand/model phone to ACCEPT a higher charge rate?"
Since you have provided no useful information about your phone, no answer is currently possible.

p.s. Your NiMH power source is capable of supplying a LOT more current than your other power sources. Increasing the voltage of the power source may increase the amount of current into your phone because at some point you will destroy components in the charging circuit but you will not get it to put more into the phone battery unless you learn to communicate with the phone... Probably as someone else already posted, by modifying the voltage or resistance of the USB D+\D- terminals.

 

How do create or force current (Amps)?

by applying a voltage?

 

You increase the voltage to it.

Let's say you have a load with a fixed resistance of 100 ohms and that you have 100 volts across it.

From Ohm's law, I = E/R = 100V/100Ω = 1, so you'd have one ampere of current through the load.

If you increased E to 200 volts, then you'd have I = E/R = 200V/100Ω = 2A, so by doubling the voltage you've forced the current through the load to double.

Yes, I'm aware of that.

 

I believe what you're looking for is a constant current source but remember its all relative. Voltage WILL increase as current does if the load remains the same

 

Guys, he wants to charge a cellphone - a device that includes its own charge controller designed to run on 5V. Increasing voltage or using a constant current supply are NOT good options and could damage his phone. He needs two things: A supply capable of supplying the maximum current that the phone demands, and possibly way to tell the phone to not throttle charging because it doesn't recognize the source.

 

Guys, he wants to charge a cellphone - a device that includes its own charge controller designed to run on 5V. Increasing voltage or using a constant current supply are NOT good options and could damage his phone. He needs two things: A supply capable of supplying the maximum current that the phone demands, and possibly way to tell the phone to not throttle charging because it doesn't recognize the source.

He (they) are not listening. I'm waiting for the humorous post about an iPhone exploding.

 

I think it'll be less entertaining than that, but yeah, I don't see this one ending well. Win some, lose most.

 

The TS has covered similar ground in previous posts and yet, here we are again:

http://forum.allaboutcircuits.com/threads/how-do-you-output-current.120603/

http://forum.allaboutcircuits.com/t...phone-charger-a-little-help-is-needed.102912/

 

I'll just try a slightly higher voltage.



Ok, so if the phone is getting 5vdc of voltage, and is only accepting 0.424A of current, than that means it has a resistance as a whole of 11.7924528301887Ω resistance.

If that's true, which it is.. Then passing 6vdc, threw 11.7924528301887Ω of reistance (Note 4), then the current should increase to 0.508A

and if I try to pass 10vdc, to the phone, with the phones internal ressistance of 11.7924528301887Ω, then my DMM should read something like 0.847A..

That's too much voltage.. But I think I might be onto something.

Current (The Ampere), doesn't come from thin air, it's generated. It's defined as an X amount of electrons passing a given point, per second.

Voltage, on the other hand, is NOT an Ampere. But they co exist together, and are determined by Ohm's law.

I = E/R, I = P/E, and last.. I = the sqr. rt. of P/R.

Current (The Ampere) is equal to Voltage divided by resistance.
Current (The Ampere) is equal to Power divided by voltage.
and Current (The Ampere) is equal to the square root of Power divided by Resistance.

One does not exist without the other. Ohm's Law 101.

So..

How the hell can I make more current.

The Phone isn't alive. If I went out and bought something that someone else made (ANKER CHARGER) I could force the phone to take whatever the hell I wanted to give it, and the phone couldn't do jack about it, because it's stupid. It's an inanimate object. It's not living. And even a person is stupid, and if I wanted to put you in the electric chair, and pass 1000 Amperes of current threw your body, I could do so, because people are stupid.

So.. Let's see here.. You saying that putting more voltage on it is a really good answer, but I could damage the phone, because I need far too much voltage to get 1A of current. Ohm's Law proves that giving more voltage, when the phone indeed has a resistance as a whole, would allow me to pass more current to the phone, by simply increasing the voltage. That's easy, and it's too easy, and in turn, would "YES" damage the phone if I took the voltage too high, because after all, the phone is stupid and is just a punch of plastic, metal, and chemicals.

So I honestly need to sit and think a little bit, because I think just with the answer of the higher voltage, I could figure out the missing piece to the puzzle, just by using Ohm's Law.

Ohm's law is smarter than the phone, it governs the whole idea how the phone is made. Without Ohm's Law, the phone doesn't work.

So.. I need to sit and think for a while, until I can think of what the missing piece is.

Thanks for the help so far, some really good answers from helpful people.

If I wanted to be funny I'd say it was a smart phone.
If you look at the cord that plugs into it for charging you will see it has several contacts. This allows it to talk with the USB port you plug it into. Some USB ports can't supply 1 amp, others like your Anker can. So the two of them decide how much current to charge with. I don't know what pin it is that tells it one amp, but someone might.