XPS 13 9343 Custom Charging

I'm trying to use the custom charging options within BIOS (version A03) to control my battery charging. I have set it to start charging when the battery dips to 50% and stop charging at 80%. However, I have never seen it actually work. It just charges all the way up to 100%.

Does anyone know if custom charging (or for that matter adaptive charging, standard charging etc. as listed in the BIOS) works for the XPS 13 9343's battery?