Need help with battery powered USB charger

[quackduck314]

So, I took apart a 12V car charger (USB output), and wired it to 5 AA (2000mAh, 1.2V) batteries in a battery pack. This was enough that when I plugged in my phone via a USB cable, it registered as charging. However, it appears that my phone's battery life is decreasing, rather than increasing. Any suggestions?

I tested the charger with a car's outlet, and it worked. It has an indicator light which only comes on if the electric circuit is properly connected, so I know the connection and flow are right, and the terminals didn't get swapped.

 

[Megatron]

The drain from the device was greater than the charge of the batteries. Yes it is only a 12V adapter, but it constantly draws 12V from the car and uses that to charge the phone. You gave the adapter 6V, which is half of the normal draw, and not even constant like a car line.

So yeah, you will need a much more powerful battery source, something that can give 12V constant and for a period of time that you need to charge the battery. Now depending on the device, a normal charge cycle can be for up to 8 hours. I highly doubt you will find a solution out there using AA or any battery type that can do that for you. It is for that reason they made battery packs and replaceable batteries. Cause trying to use AA batteries to charge a cell phone, just wont work.

 

[quackduck314]

Well, things like this exist on the market and work, even ones that only use two AA batteries. I guess the question is, what piece of hardware do they have that prevents it from doing what mine is?

 

[Megatron]

Those things also have a computer built into them so that they can regulate the voltage and power consumption. You rigged a cord directly to batteries and expected it to work. Guess what? You forgot the all important voltage regulators, capacitors and other things that make such devices work.

So yet again my original comment stands. You cant just hook up batteries to a cable and have it work. I cant tell you what they have that you dont as I have never reverse engineered one of those units. But that is what it will take for you to figure out the answer to your question.