Battery monitoring method and apparatus

A battery monitoring apparatus comprising:

• (a) a voltage sense input port to which leads extending to a battery may be connected such that a signal representing the voltage across the battery is provided to the voltage sense input port;
• (b) a current sense input port to which leads extending to a current sensor may be connected such that a signal representing the current through the battery is provided to the current sense input port;
• (c) an output communications port through which data may be communicated;
• (d) a non-volatile memory;
• and
• (e) a programmable microcontroller connected to the voltage sense and current sense input ports to receive signals therefrom and connected to the output communications port to at least transmit signals thereto, the microcontroller connected to provide data to and from the non-volatile memory, the microcontroller programmed to monitor the signal from the current sense port to detect a change in battery state from one of the states of battery charging, discharging, and open circuit to another state, and to define a battery event between changes of state, to monitor the battery voltage and current during each event, to store data to the non-volatile memory after an event including at least the time and state of the event and the total current over time as supplied from or to the battery during the event, and to selectively transfer data from the non-volatile memory through the output communications port after a period of time in which events have occurred.