IPhone Charging is not supported with this accessory? FAST

So I have an iPhone 3GS 8GB iOS 6.1.3 jailbroken and my original charge cable broke. Bought a new one and that charged perfectly. That one broke too. Bought another from the same shop and when I connect the cable to the original wall connector it says Charging is not supported with this accesory. I tried connecting the charger to other wall ports but didn't work. After that I tried connecting the cable to other connectors. I tried to connect it to my brother's LG connector and it charges perfectly. But the LG's adapter's output is 5.1V and the Apple adapter's output is 5V. What should I do so I would make the original charger work? I want to sell this phone so I need to fix it. Also my brother needs his adapter because my one is charging his phone too slow. FAST ANSWER Please?

I would recommend buying a new charger from the Apple Store- and don't break it! If it still doesn't work, contact Apple Support.

Explained here: http://www.gatorspit.com/tips/iphone-wont-charge.html