There is a widget call Readme pre installed in the phone, teaches basic user guide & faq.
*#*#64663#*#* to test the phone.
Just charge till full, modern battery doesn't require 8 hr charge like 90s Nokia era, try not to use the phone till fully drained as this phone come with battery life protection, if wait till fully drained it will require longer time to charge, the phone will slow down charging speed when it reaches 95% to prolonged battery life, when it reached 99% it will take long time to reach 100%.
If u want fast charging u can either use 2a charger or PB, original charger 1a type so a bit slow on charging.
Don't ever charge overnight as it will shortened battery life, as charger will charge the phone once the battery level dropped, so overnight might be many cycle charging, since battery r limited to certain amount of charging cycle, by charging more battery life shortened.
Yes ! Does Good.
Thanks for your reply. Mind I asking the 10.4k mAh xiaomi pb is 2a or 1a type ? Couldn't get the pb when I bought my mi3 so I have no idea what's that.