As it happens, I’ve just finished setting up a system exactly like this for a completely off-grid setup. I needed a Raspberry Pi running Home Assistant to be completely self-contained to monitor an adjacent, larger system that is only powered up intermittently (close enough that the two systems have a common ground).
Short version: the Raspberry Pi and the Huawei LTE router I’m using for connectivity draw a steady 9W between them (there’s a lot of monitoring going on). I went with an old pair of 80W panels in very suboptimal positioning, a simple MPPT charge controller and a 110Ah deep cycle leisure battery which costs about €45, €30 and €120 respectively. The system has been running a few months now and the battery had never, ever dropped below 12.4V. The Pi uses WireGuard to connect to my VPS so Home Assistant can be accessed with a web browser since the network I’m using on-site doesn’t do public IP addresses.
As it happens, I’ve just finished setting up a system exactly like this for a completely off-grid setup. I needed a Raspberry Pi running Home Assistant to be completely self-contained to monitor an adjacent, larger system that is only powered up intermittently (close enough that the two systems have a common ground).
Short version: the Raspberry Pi and the Huawei LTE router I’m using for connectivity draw a steady 9W between them (there’s a lot of monitoring going on). I went with an old pair of 80W panels in very suboptimal positioning, a simple MPPT charge controller and a 110Ah deep cycle leisure battery which costs about €45, €30 and €120 respectively. The system has been running a few months now and the battery had never, ever dropped below 12.4V. The Pi uses WireGuard to connect to my VPS so Home Assistant can be accessed with a web browser since the network I’m using on-site doesn’t do public IP addresses.