Hi,

I use the Aux output as follows, and it works well. My criteria is that I want to heat up all my geysers once my batteries are full and there are excess solar, effectively use them as storage.

All 3 my geysers are wired to my essential grid (everything in my house are wired to essential grid), each with a CBI smart switch. Below the smart switches, I have a common contactor (each geyser on a NO contact) that prevent my geysers from getting power even if the smart switches switches on. I then have the contactor coil supplied either from my Aux out, or another CBI that I can control remotely.

Aux out set to switch on when battery is at 98%, off when at 95%. Then the first (most important) geyser has a timer switching on at say 09:00. Even when this happens, the geyser still don't get power since the contactor is still off. Only when the battery is full and Aux out energize, will this geyser get power. I then wrote scenes on the CBI app to switch on successive geysers when power goes below a set value (geyser is warm), so all geysers get power, one after the other.

If there are clouds, I can force the contactor on with the "Master" CBI to heat up anyway.

Works well, except that sometime when solar is not great, the battery will charge and once the geyser switches on, it draws down the battery to switch off at 95%. The CBI then sees this as a warm geyser, and toggle to the next geyser, and so on. But when the sun shines it works great.

It will be great if the solar setting on Aux output was an "or" and not "and" to battery state, since it sometime takes a long time to get the battery full, leaving less time to get the geysers warm in the day.

Groete.

Hey guys

Struggling to wrap my head around the Aux functionality...

Currently my entire house is run off essentials, including geyser - with the geyser on a smart switch. This worked fine until I had kids, and now I have to run the geyser later and later into the evening, so now it's running quite a lot of the time off my battery in the evenings. Generally I make it through the nights with no grid usage, but it's cutting it very fine, and if we ever had to start load shedding again or if I had an electricity fault at night, I could be left without power.

So what I would like to do, if possible - is run my geyser off solar first, if possible. If not enough solar (or it's night...), run geyser off grid. If grid is off and not enough solar, only then run off battery.

Is it possible to do this with Aux and the various settings? And how flexible is it? Could I make it work like the above, but use some of my battery if I wanted to (by adjusting some of the battery settings under aux)?

I have Home Assistant and Solar Assistant, so making changes remotely is not an issue if I wanted to vary behaviour, but first I would like to know if Aux meets my base needs in the first place.

Thanks!

51 minutes ago, gu3st said:

I have Home Assistant and Solar Assistant, so making changes remotely is not an issue if I wanted to vary behaviour, but first I would like to know if Aux meets my base needs in the first place.

I know this is not what you're asking re Aux, but it is another option to consider since you already have HA running and integrated.

What I've done is run my geyser, oven and pool as non-essential. That way they can all run off solar during the day.
Then at night (around 5pm) I switch the inverter settings (via Home Assistant) to not export any power to non-essentials - so if the geyser runs at night, it runs from grid, not draining my battery reserve.

This has worked well for us. The only downside is that, during load shedding, I will never have a geyser. (I'm assuming that with the Aux method you will still have hot water if you have enough excess solar, but I haven't looked into that myself. From what I've heard the Aux functionality is very limited though.)

1 hour ago, gu3st said:

Currently my entire house is run off essentials, including geyser - with the geyser on a smart switch.

To me the only reason to use aux is if you don't have the option to remotely control your load. Just leave things as they are and set your minimum SOC to the safe value in case there is a grid failure. Whether the grid is powering your geyser or other appliances in your house makes no difference. So use your battery to supply the geyser and the rest of your house until you hit your minimum SOC and then grid will power everything until the sun comes up or you hit your next safe SOC time.

Here is my SOC schedule - you can see the decreasing SOC as the night progresses, with each being how much stored energy I need to make it through until morning. This has taken some fiddling and changes with the seasons but works really well. We have everything except our oven on essential.