[Help] Power Manager Dell Votro 3400

Hi!
I have a Dell Votrol 3400 laptop, I bought it a few months ago, initially in my MyDell app there was a link to the Power Manager, and I set the battery charge to the lowest 50% and stopped charged at 90%, and it worked fine, recently, when the computer updated Windows and BIOS by itself, now MyDell has no link to Power Manager anymore, and I have to open Power Manager through search, in settings set still save 50%/90% and it didn't work, when my laptop always fully charged at 100%, there's no entry in my BIOS for Power Manager either. I have uninstalled MyDell and Power Manager and reinstalled it through the Window Store, but it still won't link and it can't stop charging as set. What do I do now? Sorry English is not my primary language. Thanks very much!