30% battery on iphone left, how long will it last?

How many mins/hours

It depends on if you're going to be constantly using it if you are then not long

If you keep using it I would say half an hour to an hour if you turn it off for while and only put it back on when you need it then it could last a few hous/

If you keep using it

it will last 30 to 45 mins

It's depend on your use. Without use maybe couple of hour (tested on iphone 5)…

Lol iPhone.