MJSfoto1956
10 kW
For those who are using (or considering using) the Xiaoxiang app to control their BMS's, here is a quick tip to get the most out of it. There is a config setting that allows you to "tell" the app what constitutes 80%, 60%. 40%, and 20% battery usage. The default settings are "fine" as far as they go, but if you want to be a touch more precise, then here's how you do it.
First, find the capacity/discharge curve for your specific battery. My battery type is LG F1L 3350mAh 18650. A quick look at the chart (see below) indicates that it is closer to a 3100mAh battery in spite of its marketing. No worries. I'll just use 3100 * #of cells in parallel as my pack's total Amperage.
Next, divide your discharge curve into 5 vertical sections representing 100%, 80%, 40%, 20% and 0% (i.e. full charge to as empty as you are willing to let your pack go). In my case, I used from 0.0mAh to 3.0mAh as my range and divided it up accordingly. Next choose an "average" discharge curve to represent your normal riding. In my case, I used 3A. Where the vertical lines intersect the 3A line, I drew horizontal lines to the corresponding voltages. See diagram below.
Finally, use those values to type into the Xiaoxiang app. The result, while not perfect, is a much more "accurate" gauge of remaining battery power left.
Needless to say, the settings work very well in the middle of the discharge curve. Towards the ends, it is not quite accurate given the coarseness of the settings. Better would be 10 settings. But 5 it is.
YMMV
Michael
First, find the capacity/discharge curve for your specific battery. My battery type is LG F1L 3350mAh 18650. A quick look at the chart (see below) indicates that it is closer to a 3100mAh battery in spite of its marketing. No worries. I'll just use 3100 * #of cells in parallel as my pack's total Amperage.
Next, divide your discharge curve into 5 vertical sections representing 100%, 80%, 40%, 20% and 0% (i.e. full charge to as empty as you are willing to let your pack go). In my case, I used from 0.0mAh to 3.0mAh as my range and divided it up accordingly. Next choose an "average" discharge curve to represent your normal riding. In my case, I used 3A. Where the vertical lines intersect the 3A line, I drew horizontal lines to the corresponding voltages. See diagram below.
Finally, use those values to type into the Xiaoxiang app. The result, while not perfect, is a much more "accurate" gauge of remaining battery power left.
Needless to say, the settings work very well in the middle of the discharge curve. Towards the ends, it is not quite accurate given the coarseness of the settings. Better would be 10 settings. But 5 it is.
YMMV
Michael
