Antwoord op "CPU slow when battery low!"iPhone 6s. Mine was/is slow and lagging anywhere under 50% battery. After reading some of your answers in here, as I had no clue, I plugged the charger in, and it seems ok again. I’m not convinced a new battery will help, but I cannot only use my mobile when it is charging. Anyway thanks for all your replies, it does help in the meantime, as without the charger plugged in it was just about unusable.