Thanks for the response, I'm learning that now, the ruixu says it'll charge at -20 in the documentation, guess what, it wont, I had to set up a diesel heater in the back of my van to get it above 0 and they finally took a charge, and ruixu support ghosted me.
I also received my dawnice batteries, the build quality is terrible, I had to re-drill and tap 3-4 holes at the bottom for the casters because they did a piss poor job, most of them were on angles. One of the two batteries has a fault light on, support is helping me at the moment with that but we'll see if the treatment is better.