Power tank with 240v inverter

[Coastliner]

Can anyone recommend a power pack with 12v + usb outputs that also has a 240v inverter for powering a small laptop?

[ronin]

If you mean the type of things sold as power tanks by Halfords, Celestron etc then I suspect none will do the job. I would say you are looking at a decent sized battery and a deep cycle one as used in golf buggies and similar.

An inverter will take about 10% of it's rating just to operate.

I would think you are looking at a good sized deep cycle battery.

If it is for an observatory then buy a solar panel or two and let that/them maintain the level of the battery.

[Coastliner]

Thanks Ronin.

Deep cycle - are these the so-called "leisure " batteries? And would I be better off buying an adapter that would convert 12v to the 18.5 v my laptop needs? The rating of the laptop power supply is 65w.

Neil.