Megarevo RxLNA Discussion

[fromport]

I just updated the firmware and all my settings are the same as yours. My battery is at 99% SOC and it is finally outputting to the grid.

Excellent!

It is weird though. It is showing INV: L1 putting out 13.5A and L2 putting out 11.4A. They used to be matching...?

Could be a lot of things, I wouldn't worry too much.

Those numbers seem awful low. My Tigo app is showing 5.1KWH to the inverter. Just before the upgrade (a few mins prior, same clear sky) I was getting 25A per phase on the INV output screen.

5100÷240=21.25 amps.
Deduct converting losses from inverter from 5100 and you should see a lot less than 25 amps.

 

[Slvrsky07]

It did a reset and both are showing closer now. Would you know what settings I would change to have the battery discharge to 20% SOC before recharging? Right now it’s constantly trying to top it off.

 

[fromport]

Would you know what settings I would change to have the battery discharge to 20% SOC before recharging? Right now it’s constantly trying to top it off.

Why would you want to do that?
I think this is the most efficient mode:

Self-use (with PV Power)
Priority: load -> battery -> export to grid

During the day the the batteries are topped off.
When the sun goes down:

Self-use (without PV Power)
When no PV supplied, battery will discharge for local loads firstly, and grid will supply power when the battery capacity is not
enough.

That way you use battery capacity until batteries empty and then switch to using the grid.
Downside is if there is a power outage, your batteries are already discharged and you might not make it through the night.

Since I had only 1 day with batteries, I am still learning about the settings.
They are not self explaining and not intuitive to me (yet)
This is the graph of yesterday:

Batteries took over _part_ of the load when the sun went down and discharged to 88% at midnight.

And then this morning:

batteries charged first till it gets dark again.

How would you like it to behave?

 

[Slvrsky07]

What you say makes sense. I think once I get more on my loads panel it will work better.

 

[fromport]

There was a serious threat about rolling power outages here in Californina yesterday.
I simulated one by flipping the breaker to the grid. This was my first test for running semi-offgrid.
Some of my heavy loads are not behind my MR (AC,hybrid water heater, induction stove, EV) but I didn't use those yesterday, i basically switched all those off till 10pm. This morning we did our usual stuff, baking off a bread , coffee machine. It turned out those 2 loads are at the same phase and I saw this at the MR display:

LOAD POWER PERC
L1: 2923W 74%
L2: 33W 1%

The MR should be able to run 4000 watt per phase independently, which is nice to know.
Batteries were down to 49% and now are charging from the Sun again

I asked technical support with help of my system. They looked over my settings (that I published earlier in ascii) and they advised me to turn off 2 setting:

When asked why I got these answers:

SYS SETTINGS -> 3: BAT WAKE-UP: 1. DISABLE
the battery wake-up is when the battery is empty, the inverter can give a voltage to recharge the battery at present this function need to be customized

SYS SETTINGS -> 4: REMOTE CTRL -> 1. DISABLE
the remote control is for the customer to program the inverter interface, currently not open

I do not really see if something is not open or needs to customized how that would influence the system performance, but I disabled that as requested.

Will report if I get more (useful) information from them.

 

[jsmetalcraft]

Help me out, what is "baking off a break"?

 

[fromport]

Help me out, what is "baking off a break"?

Haha.. typo... bread. From europe so real bread monsters. We don't like the sweet US bread, so we make/bake our own bread every other day.
Just a typical convection oven on 450F for 50 minutes, that was the load ;-)

 

[jsmetalcraft]

Mom made bread growing up grinding her own wheat, and wife made bread for us but used a bread maker machine. I don't care much for most breads in the stores. Now I eat as little bread as I can due to carbs, and as little sugar due to pre-diabetes. BTW I am 4th gen sugar beet/ wheat farmer.

 

[fromport]

Mom made bread growing up grinding her own wheat, and wife made bread for us but used a bread maker machine. I don't care much for most breads in the stores. Now I eat as little bread as I can due to carbs,

Smart, we should try and do that as well.

and as little sugar due to pre-diabetes.

Necessity, but also smart.

I was surprised that the MR had no problems supplying 74% of max capacity at one phase and only 3% on other phase.
On the other hand you realize that eg a microwave for just a minute on the same phase wouldn't have worked, so I am seriously thinking about paralleling a second MR.
I just found out 2 days ago my batteries are 120Ah but only 15S = 5.76 kWh, 5kWh usable.
I had the intention to parallel those with a bunch of 19" batteries but that is not going to work since they are almost all 16S.
So 2nd MR will get it's own set of batteries
Different capacity so could run into problems when charge gets low

 

[NCSolarGarage]

An interesting note about the battery wake up is that I found out on my lead acid setting, the EPS does not turn off when the "END VOLTAGE" (48 V) was reached. My BMS turned off discharge at 45v. The problem here is that the MR no longer senses the battery because no output from BMS and no communication hooked up. Luckily, the batteries somehow settled back above 45v, which turned on discharge and therefore supplied the 45v (no load with the eps off) to the MR. Fortunately, the sun was out when this happened and therefore the battery began to charge.

I originally thought this was because I have Batt Wake Up enabled. Apparently I just got lucky?

 

[fromport]

I played around with Home Assistant today and added daily battery charging & daily battery discharging to my setup

In my /config/custom_components/solarman/inverter_definitions/custom_parameters.yaml I added

disclaimer: I have no idea what I am doing ;-)
Seems to work pretty well

- name: "Daily Bat Charging"
class: "energy"
state_class: "total_increasing"
uom: "kWh"
scale: .001
rule: 1
registers: [0x316D]
icon: 'mdi:battery-arrow-up'

- name: "Daily Bat DisCharging"
class: "energy"
state_class: "total_increasing"
uom: "kWh"
scale: .001
rule: 1
registers: [0x316F]
icon: 'mdi:battery-arrow-down'

I hope this matches what I see from the solarman data

 

[fromport]

I played around with Home Assistant today and added daily battery charging & daily battery discharging to my setup

I checked today and I have these graphs:

Discharge of the battery in the last 2 days:


Count was reset at midnight and around 8am solar arrived and started charging my batteries.
Around 2PM batteries were at 94% and the discharge cycle continued

That sounds about right except when I look at my charge graph:


There seem to have been a very slow charging of my batteries from the grid as well

Looking at the solarman graphs it seems to have taken terms charging/discharging

Green (discharging) and yellow (charging) were both active.

So the graphs are probably pretty accurate.

I updated the icon in the code with an up (charge) & down (discharge) arrow ;-)

 

[NCSolarGarage]

Looks good! This is what I have logging in my HA so far....



It does seem to be working pretty well. Much better than the old days when data would just stop reporting from the MR

This is my charge/discharge graph

 

[NCSolarGarage]

I'm not at home right now, but I *think* I have successfully rebooted the inverter via the modbus protocol.

As posted above, I'm using home assistant to watch values in near real time. I am off-grid with batteries. I have two inverters hooked up in parallel with PV only going to my "Left" inverter. I sent a write command to my "Right" inverter to reboot, and it reset my values in HA. I then sent an OFF command to the inverter, and the values set to zero. I was able to send the ON command, and the values reappeared. Keep in my, my LEFT inverter will continue to power my loads during the reboot.

Since I'm not home, I'm unable to see what the inverter is actually doing, but via software, this is looking good.

I used the PYSolarmanV5 to send this script:

def main():
    modbus = PySolarmanV5(
        "192.168.X.XXX", 233XXXXXXX, port=8899, mb_slave_id=1, verbose=False
    )

    print(modbus.write_holding_register(register_addr=5120, value=0x####)
    )

if __name__ == "__main__":
    main()

In the example above, replace the "####" with AAAA to turn OFF the inverter, then 5555 to turn on the inverter. For a simple reboot, you need to use address 5121, and send the value 0xAAAA.

Note, I don't know what I'm doing. I just trial and error until I get a response, but it seems to work.

 

[Slvrsky07]

How are you sending these commands to the SOLARMAN wifi adapter? Or did I miss something on how you have this connected?

 

[NCSolarGarage]

All commands for read/write are via wifi using the included solarman adapter.

GitHub - jmccrohan/pysolarmanv5: A python module to interact with Solarman Data Logging Sticks

A python module to interact with Solarman Data Logging Sticks - GitHub - jmccrohan/pysolarmanv5: A python module to interact with Solarman Data Logging Sticks

github.com

Since my computer/HA Server is windows based, I am running the python scripts in PowerShell.

 

[Slvrsky07]

That’s pretty sweet. I will have to dig into that. Thanks for the information.

 

[fromport]

Looks good! This is what I have logging in my HA so far....
This is my charge/discharge graph

Would you mind sharing your .yaml config file with us/me ?

 

[NCSolarGarage]

Unfortunately, I don't know enough about VMs or how HA works so I can't upload the yaml (I don't know how to access the file system, lol), but I copy/pasted into a text file. I do all my editing of the yaml thru the HA file editor directly.

 

[fromport]

I currently have 3x 5kWh usable batteries hooked up to my MR.
I moved about 95% of my home to my critical load panel.
Heavy electric loads are still on the grid and during the day (when possible) I run the AC, charge my EV etc.
This has now resulted in 2 interesting days:


3 strings connected to my MR produced almost 44kWh yesterday
As soon as the sun set, the batteries took over:

Lowest SoC of the batteries was 37% and before noon the batteries were back up to 95% charged.
Apart from the MR i still have a few other PV systems active.
I read the meter at midnight and log the readings.
According to those logs the "from the grid" meter had advanced 0.81kWh and the "to the grid" had advanced 67 kWh.

Tomorrow I hope to add the 4th battery, that would make it 20kWh usable storage capacity to the inverter.

The most funny thing is that I talked to a neighbor briefly that said "yesterday evening there was a power outage, just over an hour, and your house was the only one with the lights on"
We were totally unaware there was no grid power.