There's a chap that used to sell stuff on eBay for about £20 that is
basically a car plug to a variable output power supply for a laptop.

Good idea - I checked and there were a few different ones there - a lot
cheaper than the inverter, thanks.

"""Do you know anywhere on the web that stocks a good range of suitable
batteries ?"""


I understand Lidl were selling off a number of suitable battery units
as one of their weekly deals. I think this particular one may have
gone though.

I'll check it out, thanks.

Regards,

Andrew