QIH_Electric

Solid choice going down the LiFePO4 route — worth every penny once you're past the initial setup headaches. One thing I'd flag immediately: venting requirements for LiFePO4 are actually far less...

Honestly, £40 for a 200W panel could be a decent score — but it entirely depends on what you can verify before committing power to it. First thing I'd do is check the label on the back.

The shunt spec is absolutely critical — @Stu1991's spot on there. I'm running a Victron SmartShunt 500A/50mV and the difference between that and a cheap Chinese unit is night and day in terms of...

I'd push back slightly on ModBus TCP being the starting point though. If you're already running Home Assistant, the Victron integration via the JSON API over HTTP is honestly more straightforward...