[Galaxy Note II Q&A, Help & Troubleshooting] Alexei Volkoff:
OK. Lets start troubleshooting your problem but first some basics to help you better understand the issue and maintain your battery in good shape and maximize its longevity:

Full battery discharges - until power shutdown (0%) - or discharges that drain the battery below 3% must be avoided because they stress the battery and cause premature wear. It is better to perform partial discharges and frequent charges instead of performing a full discharge followed by a full charge. I never let my battery drop below 5%.

A discharge/charge cycle consist of using all of the battery charge (100%) but not necessarily at once. For example, you can use half its capacity then fully charge it. This is not a discharge cycle, it is only half of a cycle. Only if you do this twice does it counts as a single discharge cycle (50%+50% = 100%). Same goes if you use 30% then charge, then use 20% then charge, then use 25% then charge, then use another 25% then charge. You charged 4 times but you only did one cycle (30%+20%+25%+25%=100%). So it may take several charges/discharges until a full discharge cycle is completed.

Charging speed depends on the amount of current the battery is fed. The Note 2 can be charged with a max. current of 2A (2 Amps) or 2000 mA (2000 milliamps). If you check the stock charger's specifications, you'll see that it's output is 2A. However, not all USB cables can conduct this amount of current. So, even if the charger is outputting 2A the battery may be being fed less because the cable can't handle 2A. Hence, the importance of the cable. One way to check this, is by installing a software that can read the amount of current that is being fed to the device. I personally use "Galaxy Charging". It is free and serves its purpose.

Also, charging speed is not linear. You probably have noticed that when you charge a totally drained battery, the first 20% are charged pretty quickly and the last 10% are rather slow.

Last, if you charge your device through a regular USB port from your computer or another device, it is perfectly normal that it charges much slower since the original USB specification defines an output current of 0,5A. Even the so-called "charging ports" from today's laptop don't output 2A (not any that I know, at least). The fact is that even most wall USB chargers don't output 2A and even some of the ones that claim they do, actually don't.

If you are having trouble understanding any of these theoretical facts about charging, please let me know and I'll try to explain them better. I don't know if I got through to you.

So, let's see what is wrong.

1) Download "Galaxy Charging" from the Play Store. There may be other, but it seems this one is popular among XDA members, so it is easier to compare figures.

2) Take the cable with which you are charging now, the stock cable and another USB cable.

3) Make sure the battery is more than 20% charged and less than 80%.

4) Shut down all apps, including the ones that are running in the background. Take note of the initial battery level (%). Charge the battery using your regular cable. Run "Galaxy Charging", check the "Now" input current and take note of it. Let it charge for a while (no need to fully charge it). If you want to, you can also take note of the charging time. DON'T USE YOUR PHONE while charging!!! If you do, you won't be able to truly compare the measurements.

5) Take note of the "Maximum", "Now" and "Avg" figures in "Galaxy Charging", unplug the charger and take note of the final battery level (%).

6) Use you cellphone until the battery level drops to the initial battery level at the begging of the charging procedure. Repeat steps 4) and 5) with the other cables, not forgetting to take notes of the currents measured by the software.

This may sound like a pain in the a$$ but unless a procedure is repeatable, you cannot draw any serious conclusions. The initial and final battery levels must be the same because, as I said, charging is not linear. So, the range at which this experiment is conducted must also be the same. Also, charging times can be affected by variables like: battery age, room temperature, mains current variations, how low the battery level is and so on. So, other people's charging times are a rough guideline only. Not to mention the people who use their phones while charging or keep a zillion apps running in the background and them post their times on the forums like if they meant something.

Let me know your findings. I'm sure you will find something of interest if you take the time and trouble to follow these steps and maybe we can all learn something in the process. Good luck.