Are those cheap inverters they sell in Lidl etc for about a tenner,powerful enough to charge a laptop?
A 150 watt inverter will be powerful enough to charge most laptops. Have a look on the power brick you have for your laptop, there will be a sticker on it that shows all it power requirements and will give the maximum wattage. My Acer laptop is 65 watts while my HP is 90 and I can charge either of them with my 150 watt inverter.
Some makes are more fussy, Sony and Toshiba in particular and they often require a pure sine wave inverter which produces electricity more closely resembling the type of electricity you get from the mains and while they will work on some modified sine wave inverters they may not do so on the cheaper ones.
Leonard Hatred:
Are those cheap inverters they sell in Lidl etc for about a tenner,powerful enough to charge a laptop?
Try this
maplin.co.uk/Module.aspx?ModuleNo=44736
works off 12v