I recently installed a Victron Cerbo GX in order to remotely monitor and control my solar panel system using my Victron MPPT solar controller. The Victron equipment is set up to use a Bluetooth connection, which is not helpfull when I'm away from the coach. I have full-time internet access through my Peplink cellular router, so the Cerbo GX solves the remote access problem, with its built-in WiFi capability. I like to keep my LiFePO4 batteries at a SOC between 35% and 75%, so I can now turn off the solar charger when the batteries get to 75% using the Victron VRM web portal to control one of the relays in the Cerbo GX.
I have found the Cerbo GX to be an incredibly feature-rich and usefull device, with a multitude of controls and complex capabilities. I have been experimenting with additional features - I've added four temperature sensors (wet bay, outside port & starboard and interior) so I can view temps through the portal. At some point, I will replace Newmar's (crappy) tank sensors with a replacement that will tie into the Cerbo GX. The latest experiment was to see if I could start and stop my 8KW Onan generator using the included auto- and manual-generator start capabilities built in to the Cerbo GX. I have a Magnum ME-ARC50 remote and Magnum ME-AGS-N AGS, but I have found it clumsy and I don't like the fact that I cannot monitor what it's doing when I'm away from the coach.
The Onan generator is a 3-wire type which requires momentary switches for both starting and stopping the generator, so it's more complex than just turning a relay on or off. Victron offers
a solution for 3-wire generators, but their advice is a bit difficult to interpret. The gist of it is that you need to use timing relays. Their suggested relay is the Crouzet MUR3 relay, which is now obsolete, but still available for about $150 each - and you need one for starting and another for stopping. I didn't want to spend that kind of money, but I was able to find used ones on eBay for $35 each. That was worth the $$ to try it out.
So, I have it set up and working. The Cerbo GX AGS system is fairly robust - it has a manual start (with a run-time setting) and will auto-start the generator based on SOC, voltage, current, etc. It has the usual settings for quiet time. It will also set up a periodic run of the generator, which I will use while in storage to exercise the generator once a month as recommended. It does not have a setting to start the generator based on inside temperature like the Magnum AGS does, but I can monitor inside temperature with my added inside temp sensor on the Cerbo GX, then manually start the generator so the AC units will run. All of the controls are handled in the VRM web portal.
I've run this setup through the paces, and it seems to work reliably. I'm a big fan of remote control and monitoring, and adding the generator to this ability is a great addition for me.
I've attached a wiring diagram that I used to set up this system. Since I already had the Magnum AGS, I simply wired the start,stop and common outputs from the timed relays into the connection block on the Magnum AGS. The two seem to work together just fine. Since my solar controller, the Cerbo GX and the Magnum AGS are all physically located in the same basement bay, wiring was easy.
I can highly recommend this addition to provide anywhere monitoring and control of the generator.