3.2 Charge State

In Charge mode, the battery charger is enabled while the system monitors the input voltage, battery voltage, battery temperature, charger status and the communications port.
  1. If the charge is complete, the state machine will switch to the Idle state.
  2. If the charger reports an error, the charger is disabled, and the state machine will switch to the Error state.
  3. If the input voltage is not greater than 9V or less than 12V, the charger is disabled and the state machine will switch to the Error Sate.
  4. If a status request is received from the communications port, then the status will be returned.
In addition to the periodic Round Robin monitoring the system, the ADC also accumulates periodic readings of the charge current to estimate the total charge injected into the battery. By comparing the total charge current and the starting/ending voltage of the battery against the original specifications for the battery, an estimate of the battery health can also be calculated.
Note: Because the charge current for the battery is reasonably constant, the polling of the charge current can be relatively slow, which allows the polling of the other parameters.