I know there have been posts on this in the past and how to make it work, but it’s convoluted (using a hacked Generator Assistant) and not really properly supported (especially for external BMS) even though more and more people want to do it.
Is there a reason that Victron can’t provide an assistant to do this specific job, like the generator assistant? And provide a means to turn it on and off without additional switches or relays, for example using the state of Relay 2 as an enable/disable?
For example (just a concept, not real code – I assume this would run on the Quattro):
If (relay2 is on) and (SoC>98%) and (shoreline and generator are off) and (solar power > 200W) turn on ACOUT2
If (relay2 is off) or (SoC<95%) or (shoreline is on) or (generator is on) or (solar power < 200W) turn off ACOUT2
The simple solution is to use a smart timer or switch that is IP-based and to control it via nodered. That is how many people automate loads. This assumes comms (wifi etc) is available for lan access (internet access not required).
Though you can also use node red and the programmable assistant to switch the AC2 relay via the GX relay output and AUX connection on the inverter.
I could do that, except that right now the boat is relatively new and been maintained and updated by the boatbuilder, who doesn’t use nodered. At the moment the control is done using battery voltage, which doesn’t really work when charging sources are considered – I’ve looked at using an inverted generator assistant but it’s all a bit messy.
And it seems it would actually be quite easy for Victron to produce (and support) a “water heater assistant” just like the generator assistant, especially since they introduced the solar/wind priority feature which makes it much more likely that this will be used. This wouldn’t need any extra hardware or wiring or smart switches, all the hardware already exists inside the Quattro, which already has all the information available since it reads SoC from the BMS.
Perhaps there should be a “feature request” section on the new community forum?
Hello @iand , I just tried this on a Quattro using VE Configure using fake target systems and AC2 out can be switched for various scenarios using the existing assistant. I chose to swtich it on at the end of the absorption phase of charging which means batteries are full but you could choose other criteria as well. Maybe this is a good starting point for your ability to use power after the batteries are full?
Was that with the battery charging controlled by the Quattro or an external BMS?
If the Quattro is the master then SoC can be used to turn AC2 (immersion heater) on and off, but I was told that with an external BMS voltage isnthenonly option.
I have only used the assistant to reduce the delay on AC2 out to seconds rather than 2 minutes when mains is available so have not actually done this programming. It does speak of when Absorption stops and doesn’t mention how Absorption stops, whether implemented by the Quattro or implemented by an external source so I am assuming it would apply in all cases.
