I'm confused about why in the battery usage ,there is a red line shown from last day ? Please answer.Is there any problem in battery ?

Till now I haven't get any option for AppLock. Is it true Samsung doesn't have a app lock in Samsung M21 smartphone?

One thing I really need to ask, "Does the weather heat affect the charging speed ." While seeing reviews it is mentioned there that the phone is completely charged within 2.5 hours but when I try this at home it takes 3 hours 15 minutes to charge my ...