Testing Batteries - Manual and Automated
February 2012 Page 27
Each year I like to test my ship's batteries and replace those that do not have enough individual capacity to last 3 hours at a 1A load. But how can the average pilot perform a reasonable "real world" test with easily obtainable equipment?
See the Excel spreadsheets linked below and this Soaring magazine article for an explanation of the testing that I perform and the simple test rig that I use, along with Excel templates for gathering the data and then graphing the results.
There are three versions of the spreadsheet;
2x16 LCD Display         240x320 TFT Touch Display
(Click on Images to Enlarge)
Taking hours to manually collect battery test readings can be BORING! I have now automated testing using an inexpensive Arduino Duemilanove single board computer coupled with a display shield and a few other components. There are two versions of the display used. Initially I used a simple 2 line by 16 character LCD B/W display. Lately I began using a 2.4" 240x320 pixel TFT touch sensitive color display (ILI9341) which allows more room for information, a simple graph, and other niceties.
Also needed is a voltage "divider" made from two resistors (22KΩ and 10KΩ). Lately I added a simple piezo electric buzzer to chirp at each reading and then alarms at the end of the testing to tell you to remove the battery from the load resistor (12Ω). These components were most recently conveniently mounted on an Arduino breadboard shield (see the pictures).
The complete required Arduino hardware and associated parts might cost you $30 on eBay or Amazon.
Arduino Code - My latest Arduino software packages for each display type can be found here. After you open Arduino code packages you will find full build instructions in the comments area near the top of each listing.
Aruduino Hardware - Can be found on eBay or Amazon. The hardware specifications can be found in the comment fields of the code.