|SinusLeistungsSteller - Low-Discharge Protection|
Similar to the temperature derating, another derating on minimum battery voltage is possible, if a preset level is undershot.
If the battery is discharged below the preset voltage level, the SLS starts to reduce the power. Thereby the current drawn from the battery and the battery voltage decreases and stabilizes at an area around this voltage level. Of course the power will be reduced further and further (because energy is still being drawn from the battery), but important flight time reserves becomes available for a safe landing.
Of course, a threshold must be set at the SLS, from which a battery must be regarded as "empty" and NO more energy can be drawn.
Both voltage values of the limit, and the switch off can be set by the user via parameters. An adaptation on the battery technology and cell numbers used, can be widely performed.
In the experiment shown above a NiMh-Battery (30 cells, 3,2Ah) was discharged with a derating threshold of 28,7V and a cutoff threshold of 25.5V at the propeller test bench.