Building a simple battery charger

[gauravdc]

Hello All,
I am in the 10th grade and as part of my science-class project i decided to build a mobile-mobile charger...the way this works is pretty simple actually....
I connect a couple of AA batteries together and send the output to my mobile thus charging the mobile battery....

I have two wall chargers for my mobile which work OK.The markings on them---

First charger:
Output---5.7V ,800mA

Second Charger:
Output---3.7V ,355mA

My current progress...
I connected 4 standard AA cells(1.2V,1500mAh each) in Series thus giving an output of (4.8V,1500mAh...i think???)....but when i connect it to my phone i get the message "NOT CHARGING"....the only reason that i think this is happening is because the current is too high?(The terminals are connected correctly...i checked!)
Is this true or am i doing something else wrong?...if yes, then what is the easiest way to reduce the current in the circuit while maintaining the same voltage?

PLEASE HELP ME as soon as you can as i have very little time to give up the project...!

THANK YOU VERY MUCH!!!

Best regards,
g
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Update: a friend tells me that the current is not a problem and the phone will only pick up as much current as it needs....then why isint it working???
plzzzzz help!
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[gauravdc]

this was posted on another internet page....
hope one of you can read it and make some sense out of it
"""the phone would start charging when the power supply was at 5.2V, and would stop when it went down to about 5.09V. Given the 0.6V drop across the diodes this means that the phone happily charges at 4.6V (at 350mA!) but not 4.5V (2mA) -- much more sensitive than I expected, but not too suprising."""