Configuration Calculator

This page will help you pick part values for your battery board.

This calculator is a goal-seeker. If you don't like the answers, change the goals slightly. :)

If the charge time is 10 hours or more, the calculator assumes you're making a trickle-only charging board. It leaves out R1, assumes that there is one fewer diode drop along the charging path, and doesn't calculate Vsen divider resistor values.

Some of the rules the calculator follows are:

Number of cells:
  Cell capacity:  mAh
  Charge time:  hours
  Regulator type:  Standard (NPN)
  Backup fast-charge
termination method:
 Temperature-based (not implemented yet)

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Updated Fri Dec 16 2022 12:23 MST Go back to The PPA Project Go to my home page