You may remember last spring that I did some testing under load of my (and others) LiFePO4 batteries. After a year's worth of soaring I tested my two batteries again. Below is an update and comparison.

Tested was done with a 1A load and after just coming off the charger to when the battery has discharged to 12Vdc.

2015 Stark - Model SP-12V9-EF
April 2019 - 5.71h
October 2019 - 5.49h (loss of 13.3mins or 3.8%)
2017 Bioenno - Model BLF-1209WS
April 2019 - 8.83H
October 2019 - 8.85h (loss of 12.0mins or 3.2%)

I also updated my Arduino based testing rig's display. Previously, I used a simple 2 line by 16 character LCD B/W display. Now I am using a 240x320 pixel LCD touch sensitive color display. Oooooo, cool (and surprisingly cheap).

The new display allows me more room to display information during testing and to create a real time graph of the data. Displays are more fun than necessary but what the heck. There is amazingly inexpensive open-source hardware available for the Arduino system. The O'Reilly "Arduino Cookbook" leads you by the hand to create some powerful cool tools.

Information can be found at http://aviation.derosaweb.net/presen...s/#batterytest.