Do you notice that when charging your Galaxy Nexus using a USB charger, the charging is slower than through an AC connection? There is actually no problem with this if you have all the time to charge your phone, but if you want to make your phone charge faster when charging through a USB connection, there is a way around it. This can be done by applying a kernel patch developed by XDA Developers member chad0989.
The patch forces the phone to charge as if it were on an AC connection, even if it is actually plugged into a USB connection. It even works with car chargers, inductive chargers (through pogo pins), and MHL.
Unfortunately, installing the patch seems rather impossible or complicated for ordinary Galaxy Nexus users. As of now, no ClockworkMod Recovery-flashable ZIP file exists to make it easier for users to flash the patch to their phones.
There’s no Android app for easy installation of the patch either. So, for now, the patch is still exclusive to those who know their code, but we are crossing our fingers for an easier method soon. For now, the patch’s developer has provided the code which is intended for kernel developers only, and which, in his own words, will be “useless to those who do not/can not compile their own kernel.”
Though, if you know how to flash kernels to your Galaxy Nexus, you can flash a kernel that supports fast charge or force AC charging. (Take note that your Galaxy Nexus needs to be rooted so that you can flash custom kernels.)
According to a user report, the patch has been incorporated into the Franco Kernel. If you want to try, a suggested combo is the AOKP ROM and the Franco Kernel. So, basically, you flash the AOKP ROM to your phone, then flash the Franco Kernel.
Once you’ve got that set up, your next steps are the following:
That’s all that you have to do. Your Galaxy Nexus will now charge faster (as if on AC) on a USB connection thanks to Force AC (Fast) Charging.