[Arthur Alchin (Arthur Alchin)]

I have a Sony Vaio laptop that i use out on dark nights with no mains power around. It is used with the Meade DSI

I have a small ( but sufficient) 12v to 240v inverter that has modified sine wave (150w) but i need to find out the minimum size battery (?deep cycle) that i would need for up to 15 hours of computer use: this also includes starting off with a totally charged laptop in the first place.

The power supply for the laptop states Output 19.5v and 4.7 amps, Input is 100-240v and 1.3 amps

all comments welcome