Sentence: My phone battery finished or went dead correct it?

<1> My phone battery finished or went dead correct it? Please <2> My phone is on charge or being charged correct it? Please <3> Let's go to the hill correct? <4> I'm going to the roof correct? If I am on the roof with my friend can i say 'Let's go down' correct? <5> 'Use the ladder to go down' and 'go slowly on the ladder you might fall down correct or not correct please <6> 'Fall off a ladder' what does it mean? Thanks in advance

.
These are correct:

<1> My phone battery went dead.
<2> My phone is charging/being charged.
<3> Let’s go to the hill.
<4> I’m going to the roof. Let’s go down.
<5> Use the ladder to go down. Go slowly on the ladder or you might fall down.
<6> Fall off a ladder = Fall down from a ladder.
.

<1> My phone battery died.