Anyone got a solid breakdown of the DeWALT 20V battery pinout?

[Thomas Martinez]

Find some informations on what each pin do on the DeWALT 20V packs. Most of the diagrams out there shows the same information which is good to start with but ultimately want to know what each contact pins does.
B- and B+ are an obvious negative and positive for the cells. Then there is an ID pin to identify the battery. Next is the TH pin which is used for thermistor to measure the temperature of the battery cells. Finally the C1-C4 pins is used to tap into each group of cells allowing for balance between the cells in the battery.
The tricky one is the ID pin as there is a variety of different Dewalt tools and they all use different capacities of batteries and the tools use the ID pin to recognize if it is meant for a compact battery or flexvolt tool. So if someone were to meter the ID pin on a variety of different DeWALT packs would that value change or would it always be the same? Would it be safe to use the C1-C4 pins to allow for balance charging for the packs?

 

[Save Yourself]

the ID pin is a resistor to ground however the value of that resistor will depend on the capacity of the battery. Flexvolt tools use there own separate connection to identify the battery as they have a 20v and 60v configuration.

 

[Special Stick For Kids]

If the ID pin is a resistor then what prevents the high draw tool from simply drawing from the compact 1.5ah battery until it dies? Does the tool read the value of that resistor or simple check for the presence of the resistor?