Hi with the excess heat in the UK and coming winter months just round the corner ………
Is there a jacket to keep the AC 200 Max unit cool and warmer in winter ?
Obviously with cut outs for the vents and connections .
Or has someone made found a product that fits .
Just concerned as it get very Cold at my location .
& the battery’s dont like the Cold to much & can harm etc. 
I’m curious … in what sort of environment is your AC200 while being charged, while being discharged, and while being stored (turned off)? Inside a house? In a garden shed? In a camping tent?
Cool temperatures are generally good for lithium battery health. The AC200Max specs say the only concern is charging when the battery temperature is below freezing (0 C) or discharging when below -20 C. If your Bluetti’s location may violated those cold limits, then I agree that insulation of some kind can help (since the Bluetti produces some internal heat while either charging or discharging).
Hot conditions are generally much more of a concern, and much harder to manage. As you know the max operating temperature in the manual is 40 C, which is easy to exceed this week! While the Bluetti is charging or discharging, an insulating jacket will make it hotter (because it traps heat produced inside the unit).
Keep in mind that high heat is also bad for lithium batteries during storage, e.g. when a Bluetti is turned off (neither charging or discharging). Keep the unit in a cool place when stored. If bringing it on a driving trip (turned off), keep it out of the sun. At a camp site, keep it out of the sun.
AC 200 is inside a works unit that gets warm in the Summer and more so of late ( hopefully no more extreme heat wave )
And quite cold in the winter which i need to address.
Hence some kinda warm Jacket i may need to fabricate or buy.
But i do see many type units on you tube using them in as such artic / snow conditions but prob stored in warmer places .
Other option is see how much power i make ( solar ) in the winter or store unit away if not enough sun etc
Another LG solar panel getting next as this is still work in progress but so far its working for me .