This requires the Numpy library and the Matplotlib library, both of which can be found in Pyzo. CSV file can be found here: BattDisPlotv1.py. The python script to create the plot from a. The analysis spreadsheet can be found here: BatteryDischargeTrial.ods and BatteryDischargeTrial.xls Because it does not interfere with the operation of the device or the analysis I consider it fit for purpose, and have not bothered to fix this up.
#Arduino lipo battery monitor code#
This is just an artifact from the arrangement of my code which creates a blank line whenever a battery switches out. You will notice in the plot there are some vertical drops in the curves whenever one of the batteries has completed its discharge test and been switched out.
All batteries used in this test had been charged prior to the test. The other two NiMh batteries continued to discharge and then be disconnected from the load over the course of the following few hours. Station 3 had a particularly sick NiMh battery that was known to be shoddy and disconnected very early. Station 1, which contained a NiCd battery, automatically disconnected the load after the test had been running for about 3.5hours. Weak and damaged cells will generally show up by having short discharge times.īelow is a snippet of the output file content, and a plot of the traces.
The CSV file with the record of times and voltages for each battery test station, can then be analysed in a spreadsheet to calculate the currents, the actual energy discharged, and plot the voltage profiles. If all cells have finished, then the Arduino will ensure all relays are open and the file is closed. There is a button to stop the test for all cells, and buttons to allow the user to replace a discharged cell, and start a new discharge test on another cell installed in that test station. The Arduino then writes an artificial zero reading to the file to mark the end of the test for that particular cell. When the battery discharges to a threshold level where it is considered to be “empty” without causing damage to the battery from over discharging it, then the Arduino opens a relay and stops the battery from discharging further. An Arduino monitors the voltage at the battery terminal and records this to a file on an SD Card. All it does is discharge a battery across a load resistor that has been sized to discharge a battery at its rated capacity over the course of five hours. The battery discharge tester is quite simple. To test pairs of recovered 3.7V 18650 Lithium Ion batteries (3100mAh) the circuit would need to be modified a little by introducing a voltage divider to keep the voltage at the Arduino pins less than 5V and adjust the discharge resistors to suit the capacity. So this system, with a little modification, will be useful for him to test the health of the cells he recovers. One of my friends is also obtaining old dumped laptop battery packs and recovering the cells from them to build large “Power walls” for his solar electricity system and battery packs for powering an electric go-kart. A device that conducts a controlled discharge of the battery cells and logs the voltages seemed like a good way of doing this. Rather than identify the batteries by having my slope soaring glider fall out of the sky when the battery pack voltage gets too low, I’d like to know what batteries need some TLC before-hand. I have quite a few rechargable AA and AAA batteries kicking around that I’d like to use in various projects, but I am very aware that some of them are a little weak for lack of exercise.
0 kommentar(er)
