How to recalibrate the OS for an external battery? I recently bought an external non-standard 7000 mAh battery for my Samsung Galaxy S3 but the phone doesn't seem to recognize it. 
Is it possible that the phone needs to be reconfigured or recalibrated so as to recognize the difference in the battery capacity?
That is most definitely an INTERNAL batery, and I am also curious as to what you mean by "doesn't seem to recognize it". I'm not sure how you could install that externally as you imply. Did you follow the manufacturer directions EXACTLY? Did you charge it completely before powering yor device on? I am most curious becouse I plan to purchase the s5 version of the same battery. I'll try to keep you posted as to my results.

This is the most complete calibration method that I could find. I hope this helps. 

How to format a new Li-Ion battery. 


Plug in the charger but leave the phone off. charge your phone until the the charge is 'full' not just 100%. Then at least on the first charge leave it another 30 minutes to an hour to make sure it is full/full. 
Unplug, and pull out the battery. You need to press and hold the power button for 1 minute to discharge any current left in your phone. This current is needed to store data in your phone’s RAM. If there is any corrupt data in the RAM it will stay there even if the phone is off as long as current is still available. In reality, even if you press and hold the power button for a mere 30 seconds the current will be discharged. It is however best to do it for a longer period of time just to make sure. 
Put the battery back in and boot in recovery mode using the following method.
While phone is off Hold down the Home and Volume Up keys. 
Press and hold the Power button while still holding the other keys. 
As soon as you see the Samsung logo, release all keys/buttons (May need to continue holding volume up and home).
When blue screen appears use the Volume Down key to scroll down to Wipe Cache Partition. (Wipe dalvik as well if possible)
Press the Power button to select it. 
Press the Volume down button to highlight "Yes" and press the Power Button to select it. 
Wait for a few minutes for the phone to clear the data. 
Then press the Power button to select reboot system now. 
Wait for your phone to reboot.
Connect the phone to the charger with the phone powered on, and allow the phone to charge until it shows "full".
Disconnect the phone from the charger, and power it off. 
Pull out the battery. You need to press and hold the power button for 1 minute to discharge any current left in your phone. This current is needed to store data in your phone’s RAM. If there is any corrupt data in the RAM it will stay there even if the phone is off as long as current is still available. In reality, even if you press and hold the power button for a mere 30 seconds the current will be discharged. It is however best to do it for a longer period of time just to make sure.
Reconnect the phone to the charger with the phone powered off, and allow the phone to charge until the battery indicator shows "full". 
Disconnect the phone, power it on, and use it.
Use the phone till it shuts off by itself due to exhausted battery.
(1st time ONLY, turn on and drain battery until phone shuts down [repeat until you are unable to turn the phone on- this step is very important because we need to drain the battery completely])
-Charge till "full" before turning back on.
Repeat step 17 - 6× for ZeroLemon, or high capacity battery (3× for standard battery). (This step takes DAYS.)


You should only use this sequence one time.



Note: The easiest way to calibrate your battery is to allow it to fully discharged (until it turns itself off), then plug in the charger but leave the phone off. Charge it until "full" while the phone is off. When it hits "battery full", unplug it and turn it on. 


Recommend is do not continually drain battery below 10%, battery calibrates itself via onchip. Generally, using the phone for a week will recalibrate it. Previous steps are only recommended for a new battery.
Personal suggestion is do NOT repeat step 17 any more than the manufacturer recomends. Completely discharging,  or keeping a Li-Ion battery at "full" charge WILL place undo stress on the "chemical" battery and reduce longevity. 
Also it does seem to make sense to get the most accurate possible reads for 100% AND 0%, especially with a new high capacity battery.