At the start of December 2019, I went up to the UK coastal town of Whitehaven in Cumbria. Chris from UK Marine Electronics Ltd was about to overhaul a 32-foot sailing boat's electrics and navigation equipment. The owner wanted brand new Raymarine measuring equipment as well as a new Victron inverter, battery monitoring and lithium batteries.
Take a look at this video for how I got on: https://www.youtube.com/watch?v=q0Uu7EXJU4s&feature=youtu.be
A blog has been written about this install here: https://www.victronenergy.com/blog/2020/01/07/raymarine-victron-integration-video/
Chris himself has done a great article about lithiums charging when cold here: https://www.ukmel.co.uk/post/when-is-a-battery-cold
Along with the video, John has written this thorough blog including kit used as well as many images taken from both the video and whilst I was there.
One big topic Chris needed to overcome was how to charge lithium batteries in temperatures lower than 5 degrees celsius. After thinking out of the box a bit and lots of RS Component orders throughout the time I was there, Chris decided upon a RS 12 volt 30-watt silicon heat mat. As you will see in the video, the resistance from a PT100 thermostat gave the Venus GX tank input a measurement how cold it was and he then used the relay set in-tank pump mode to turn the heat mat on and off.