If I have a Li-Ion battery with 3 terminals and do not wish to monitor the thermal pin do I need to pull it low or high. When I measure the battery from white to red I see positive volts as do I between black and red. I assume therefore that I should either leave the white wire unconnected or connect it to the black (negative) connection. Please can someone either confirm or explain what should be done.
Unless you know the configuration of the battery pack I would suggest you recycle the entire battery pack in a responsible manner. It is dangerous to connect batteries incorrectly.
It is common to extend the life of a secondary battery pack by balancing the charge between individual cells. Here is an example of passive balancing for a 2 cell battery pack:
It does not sound intuitive to drain the charge off an individual cell to extend the pack's life. But it works.
It may be more intuitive to think about active balancing where the charge is moved from the most charged cell to the least charged cell. However, active balancing is much more complex to implement.