Dan Barlow's Webpage

This project was done to show my friend that what she wanted to do was possible.

She has a collection of antique cars with the batteries on float chargers. When it rains, the ground fault interrupter on the outlet the chargers are plugged into can trip, leaving the batteries to run down and sometimes sustain damage.

The request was for a way to monitor the battery voltage and send an alert (text or email) when there is a problem.

I chose an Adafruit Feather HUZZAH with ESP8266 for the prototype. The ESP8266 can log into her WiFi and send requests to her mail server. It has the ability to monitor one voltage in the range of 0 to 1 Volt, so we added a resistive divider to support charge volages up to 15 Volts DC. It will charge an attached lithium battery while it has power, and switch over to battery power when the outlet disconnects. It can run on the battery long enough to report the outage.

I also wrote a small demonstration of using the buttons to trigger different user modes, displaying text and graphics.