12S2P A123 packs from www.tanicpacks.com

Charging	12s2p A123 wiring diagram	12s2p A123 from tanic packs	Mastec Power supply - 12s2p A123 charged in 15mins at just over 4C

Charging with the Mastech power supply is very easy. Adjust the voltage knob to set the voltage to your packs full voltage, (You may have to move the current knob slightly to allow the voltage Knob to reach the desired value). Connect the pack and adjust the current to your chosen charge rate ( 20amps or almost 5C for 2p pack). The voltage displayed on the Mastech will drop to the actual pack voltage. It will start to rise to the the full pack value you set in the first step. This is the Constant Current (CC) phase of the charge. Once reached the voltage will remain constant and the current will start to fall as the charge continues. This is the constant voltage or (CV) phase. When the current drops to under 1 C you can turn off the power supply. With the 'watts up' in line with the charger it is possible to see the exact mAh returned to the battery. So for a fully discharged 2p pack when you reach 4600mAh the pack is cooked. This removes any ambiguity.

Here is a couple of videos which I created to illustrate the process.