RoganDawes

The wire protocol between the dongle and the elinter servers doesn’t resemble modbus at all, according to others that have looked at it already.

It doesn’t look to be encrypted in any way, but we have also still not been able to properly reverse engineer the details as yet, I believe. The kellerza/Sunsynk project does a great job, but there are also implementations of modbus for esphome (and examples for Sunsynk in particular) and other platforms as well of course.

You’d let the magic smoke out if you did 🤪 Oh, and socat is a nice way to link the two usb dongles together.

elinter is the OEM, in fact the dongle reports to their infrastructure, it seems. You can log in to elinter with your Sunsynk creds, and get the unbranded UI. I have a (n old) copy of the firmware from my dongle. As mentioned previously, it’s a RISC-V ESP32, not Xtensa, so reverse engineering it is a little bit trickier. I wasn’t able to make any progress, but they updated it since then to disable the Access Point when successfully connected in station mode, so I guess that’s all good now! keeping in mind that the dongle is using RS232 vs the ESP32’s TTL UART, you’d do better with a pair of USB-RS232 dongles connected to a PC. Do be aware that the dongle gets 12v from the inverter on one of the pins (possibly CD or RI, I don’t recall), so it won’t do anything at all without that.

Mine was updated automatically.

Not that I am aware of. If you want the Sunsynk dashboard, you are stuck with their firmware. At least they updated it to turn off the default access point after it was connected to your own WiFi!

The Sonoff THR320 is almost identical to the THD320 (aka TH Elite). As far as I am aware, it just adds a display, which is not much use up in the ceiling! Both are only compatible with digital 1-Wire sensors like the DS18b20, etc. Unfortunately, the data pin is connected to GPIO25, which is technically an ADC-capable pin, but resides in the ADC2 group of pins (pins connected to the second ADC controller), as opposed to those in ADC1. And ADC2 is unusable when the WiFi peripheral is being used, according to the ESP32 datasheet. Which left me trying to figure out how to make the analog thermostat compatible with the digital Sonoff. Hence the little interposer board. An alternative might be to remove the analoge thermistor and slide a DS18b20 temperature sensor down the thermostat. While that is a plausible alternative, I didn't want to mess around with the testing of such a thing. If your geyser is more accessible (and less essential) than mine, try it, by all means! 🙂 For more details on exactly what is entailed, please see this MyBroadband post: https://mybroadband.co.za/forum/threads/esphome-geyserwise-smart-thermostat.1231463/

I used the Geyserwise thermostat because it provides an analog reading of the actual temperature of the water, as well as the failsafe 90C physical cutout. I don't have easy access to the geyser (in my ceiling), and hot water is an "essential" in my house, as in most others, so I didn't want to play with solutions, and have to fiddle with them when they stopped working, etc, etc. The Geyserwise was thoroughly tested by the manufacturer, so I felt fairly comfortable using it myself. Also, it was cheap - R260 or so. The downside being that it was analog vs digital, and I had to work to interface it to the Sonoff.

Not sure what register the sliders are supposed to represent? I’m using the Kellerza sunsynk integration, and have the start times for each period, minimum soc and grid charge setting available. I also have the “Use Timer” and “Grid charge battery current” setting available. To adjust the sliders, I just set them to the numeric value that the slider represents. I’m using yaml, but I’m sure the same would apply using node red.

So I checked, and my settings are pretty much as instructed, except the max charge current is only 50A instead of 100A, which I think I am happy with. Just wondering if there is not a way to monitor the health of the individual batteries without relying on the inverter's interpretation of it in aggregate. Happy to put RS232 or CAN bus connections directly to the batteries if needed. Can anyone point me to the pinout diagram for the RJ11 connector?

Will check that out, thanks!

The batteries should be the same age, they were installed at the same time.

The batteries are each wired directly to the inverter, rather than using "jumpers" between batteries. They do appear to be the same length. IMG_2217.HEIC

The keypad needs an unfiltered path to the meter to allow it to communicate over the mains cabling. So if all of your plug points are on the essential circuits of your inverter, you may find it impossible to communicate with the meter. Note that the keypad should also have a battery in it that will allow it to talk to the meter even if the meter is not allowing AC to pass through it due to depleted units. If the battery in the keypad is flat, perhaps try replacing those cells? It *might* be possible to replenish your meter by taking your keypad to your less privileged neighbour, so long as they are on the same phase as you. But I would not count on it.

I strongly recommend kellerza/sunsynk for local integration that is not affected by Internet outages. FWIW, you don't have to use an RS485 dongle if you don't care about having the Sunsynk WiFi dongle connected at the same time - you can use a RS232 adapter to the WiFi dongle's port, which works just as well, and has less likelihood of complications due to the specific RS485 adapter you have chosen.

Hi, I have a pair of Greenrich U-P5000 batteries, which were installed September 2022. In the last month or so I have noticed that the reported state of charge (as per kellerza/sunsynk plugin) fluctuates as much as 20%, throughout the day. Looking at the batteries themselves, I can see that on one, the row of LED's has e.g. 4 of the 5 green LED's lit up, but the other battery has only 3 lit up, suggesting that the batteries are not charging/discharging in sync. I spoke to my installer who suggested turning one off and charging the other to 100%, and then doing the same with the other one. After doing this, it stopped jumping up and down for a month or so, but is starting again. Does this indicate something that I should be taking up with the manufacturer for warranty purposes, or could there be another reason that this is happening?

I have a 2kW element in my geyser, and a custom controller based on a Geyserwise thermostat (just the thermostat) and a Sonoff THR320. The geyser is wired to the AUX port, but the sunsynk settings basically have it on permanently. When the Sonoff turns the element on between 16:00 and 08:00, I have Home Assistant turn off the "Use Timer" setting in my Sunsynk 8kW inverter, as well as setting the "Battery charge current" value to 0A. This allows the geyser to heat from the grid during the night without depleting the battery, but stops the battery from charging (or discharging) at the same time. Home Assistant also turns off the geyser when there is no grid power available, so that it doesn't deplete the batteries either. When the geyser is up to temperature and turns off the element, I set the "Use timer" back on, and the charge rate back to 50A. So far it seems to be working well.

I have my geyser on the AUX output, but for my purposes, it would make as much sense to have it directly on the essential load. I have the AUX settings such that the AUX port is always on, and manage the geyser using a smart thermostat of my own devising (geyserwise thermostat + Sonoff THR320 + converter from analog to digital). I also changed the element from a 3kW to a 2kW, so it would not put too much load on the inverter. I use Home Assistant to change the thermostat programming depending on available PV (if battery charging at > 2500W and SoC > 80%, set to 65C). That left me draining the battery to heat the geyser at times overnight, which I was not happy about. Last night I figured out that I can control the "Use Timer" checkbox, and the battery charging rate, and now when the geyser turns on between 16:00 and 08:00, I turn off "Use Timer", and set the battery charge rate to 0A. When the geyser turns off, I set "Use Timer" on, and reset the battery charge rate to 50A. This allows the geyser to stay warm overnight without draining my batteries, but also stops the batteries from charging whenever the geyser is on! I also have Home Assistant set to turn the geyser to standby/off whenever load shedding is active overnight, so it doesn't try to heat using the batteries.

I believe the geyserwise might complain if there is no temperature increase when it thinks there should be.

If you are ok to use the built in controls in the inverter (battery level, solar generation), then it should work for you.

If you want smart control of your geyser, using HA or similar, then it might just as well be on the essential loads. The aux load doesn’t really cater for nighttime use, unless you force it to stay on permanently, In which case it might just as well be on the essentials anyway.

Yeah. Seems to me that your home load would be your geyser inverter’s “non-essential load”, so any surplus could be contributed to the house inverter. Not quite as smart as running them in parallel, but probably not an option if they are different brands/capacities/whatever.

Oh, the other thing I saw that might be of interest to folks is a 3-phase geyser element. e.g. https://reliablestore.co.za/products/220v-3-6-9kw-dn40-hexagon-head-electric-heat-tube-solar-energy-water-tank-tubular-heater-element-2?variant=41866928652449&sfdr_ptcid=28846_617_685680567&sfdr_hash=0bdc59b81b69d4572d9f9218d2e92de1 I haven't found any locally, but it seems that you may be able to get a 3kW element, which has 1kW on each phase. Of course, you don't HAVE to have 3-phase power, you can simply switch in additional elements if you have excess solar, or switch them out to reduce the load on your inverter. Might be a better solution than jerry-rigging a plate with two elements in it.

In case anyone is interested, I have my geyser hooked into my Home Assistant setup, switched using a Sonoff THR320 (flashed with ESPHome), with temperature read using a Geyserwise thermostat. The Sonoff is only able to read a digital 1-wire sensor, and the Geyserwise thermostat is an analogue thermistor, so I had to use an ATTiny85 to intermediate. My geyser is currently a 3kW, but I am planning to downgrade it to a 2kW to make it easier to actually run it from the inverter without drawing from the battery. My THR320 has 3 profiles defined, "Home", set to 55C, which is enabled at power-on, as if it were a regular geyser, "Boost", set to 65C, and activated whenever there is sufficient excess solar, and "Eco", set to 45C, which is activated overnight. It is quite interesting to see how quickly the temperature drops from 65C, but how it can stick at around 45C for 12 hours with no external input! Happy to provide more info if anyone is interested.

Sorry, I can't really help that much, because my THR320 has been reflashed with ESPHome. Just curious how you are getting the water temperature? Did you just stick the sensor onto the side of the geyser? I actually got a Geyserwise thermostat with an analogue thermistor, then had to figure out how to interface that with the THR320 which can only handle the Dallas 1-wire sensors. I ended up using an ATTiny85 to read the thermistor, and talk to the THR320 using 1-Wire. But it works really nicely now, and I'm dumping excess solar into the geyser, pushing it up to 65C when I can. Since the THR320 is reprogrammed with ESPhome, I actually have 3 presets, "Home" keeps the water around 55C, as if it were a conventional geyser, "Boost" pushes it up to 65C to soak up excess solar generation, and "Eco" drops it to 45C which works pretty well. Just really interesting to see how quickly the temperature drops from 65C, but how it will stay at around 40C for 12 hours with no external input at all!