Jacky Ickx is a big part of the history there, having some of the biggest classic races there ('69 and '77)
You can buy some at the track (if you want to get fleeced!) But something like this should be fine and cheap enough. Can also be charged via USB so either in the car via a cigarette adapter or from a portable battery pack: https://www.amazon.co.uk/dp/B078Y2HDZW/ref=cm_sw_r_apan_i_F0AMGS1EH07AERN1K9NN
For those of you not au-fait with the cat forecast, it's been going on at Pistonheads for a number of years. Regardless of how the official forecasts go, the cat forecast has been pretty much bang on for 8(?) years running.
A PH member puts his tent up in the garden and waits. If his cat goes in at the front it's going to be warm, in at the back it'll be wet. It seems that the speed at which the cat goes in depicts the intensity of the forecast. If the cat goes straight in the back, you'll spend a week swimming. If the cat saunters in the front after a while (like this year) it'll be warm on balance with some cloud and little rain (if any).
This lines up with the Accuweather forecast that suggests sun and cloud with ~25c through the week.
Time to get that sun cream ordered