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diy solar

Solar Assistant battery charged vs discharged totals seem incorrect

wayne530 said:
They are feeding directly into SA.
Click to expand...
But I have no idea where SA gets the charge/discharge information. It could still be from the inverters even though the batteries are directly connected. I can try a smart shunt but my understanding is that you cannot connect a smart shunt AND batteries to SA - only one or the other.
 
All this Solar Assistant posts are great, but making me ......
Was all set to setup SA until I saw the shortage and price gouging on Raspberries. :(
I have three running my HA in the house. My swipe one of them.
Angry that I gave away old Raspberries as I upgraded to the newer versions.

What happened to the $30 Raspberry?????
 
Heres mine with 2x LV6548's, and a DIY battery. But remember this is with Victron Smart Shunt reporting. This should pretty much confirm that its the Inverters reporting inaccurately and the shunt helps.
SA.jpg
 
wattmatters said:
Then it sounds like something is funky with your battery comms set up. What that may be I have little idea.
Click to expand...
However one thing I noted is with my Victron shunt feeding SA directly is the relevant charts in SA are not all using the shunt's data.

Some are still using the inverter's data. e.g. my charts of battery current and voltage data are from the inverter, not the shunt. But it shows the power data from the shunt. It's an annoyance which I've let SA know about and they said they were going to fix it, just not when.
 
Lt.Dan said:
Heres mine with 2x LV6548's, and a DIY battery. But remember this is with Victron Smart Shunt reporting. This should pretty much confirm that its the Inverters reporting inaccurately and the shunt helps.
View attachment 109602
Click to expand...
It suggests that certainly but there could be an issue with my setup that is causing battery charged to be 2.5x discharged and the inverter is reporting correctly - though I’m at a loss as to what that issue could be. I don’t think wire ampacity losses could account for such a large delta.
 
wayne530 said:
100% understand about the inaccuracies but to see such a large disparity in values with other forum members that use the same inverters seems anomalous to me, so I was just trying to better understand whether I have a potential issue in my setup.
Click to expand...
Ok but I have not seen an LV or EG4 that is showing correct data. The data from @Lt.Dan is from a Victron Smart Shunt.
 
My SA has only been back up for a few weeks and I erased the SD card but Wayne’s numbers look weird when compared to others. Twin LV6548 and Daly 300 bms connected to the SA. Here’s a weeks worth screen shot, day 31 not over;
 

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Skypower said:
My SA has only been back up for a few weeks and I erased the SD card but Wayne’s numbers look weird when compared to others. Twin LV6548 and Daly 300 bms connected to the SA. Here’s a weeks worth screen shot, day 31 not over;
Click to expand...
Are you using a smart shunt or is SA directly connected to your battery BMS?
 
This is mine from 2 Deye in parallels.
Maybe 1 inverter is not reporting discharge.
I see when there is no discharge from battery and run from the grid then my reporting usage from the grid doubles, I disconnected the ct's from the slave inverter and all is good.
1661988725706.png
 
I found this topic by googling exact issue. Few days ago i set up Solar Assistant and I have similar discrepancy between battery charged and discharged numbers.
In my case i was thinking battery discharge current is under reported and inverter has 100-150w self-consumption and base losses (not included in load watt and discharge current) under very low loads.
I will measure currents manually in close future. We haven't really started using the system yet.
 
Last edited:
alparslan said:
I found this topic by googling exact issue. Few days ago i set up Solar Assistant and I have similar discrepancy between battery charged and discharged numbers.
In my case i was thinking battery discharge current is under reported and inverter has 100-150w self-consumption and base losses (not included in load watt and discharge current) under very low loads.
I will measure currents manually in close future. We haven't really started using the system yet.
Click to expand...
Solar Assistant only reports the information it receives. Any discrepancy is at the source of the information.
 
alparslan said:
Few days ago i set up Solar Assistant and I have similar discrepancy between battery charged and discharged numbers.
Click to expand...
When it comes to measurement of power flows, many inverters:
- don't report self consumption
- are not particularly accurate

timselectric said:
Solar Assistant only reports the information it receives. Any discrepancy is at the source of the information.
Click to expand...
This. SA is a convenient means to access, compile, store and present system performance data, but it doesn't generate the data.
 
alparslan said:
I found this topic by googling exact issue. Few days ago i set up Solar Assistant and I have similar discrepancy between battery charged and discharged numbers.
In my case i was thinking battery discharge current is under reported and inverter has 100-150w self-consumption and base losses (not included in load watt and discharge current) under very low loads.
I will measure currents manually in close future. We haven't really started using the system yet.
Click to expand...
I’m not sure what exactly is being measured as “charged” and “discharged” for the LV6548. Is it DC? AC? I had assumed it was DC but other values reported are grid power, load, etc, which are all AC. If it’s AC, I’d expect an AC->DC conversion loss, loss due to resistance on the DC side of the wiring, then losses due to battery internal resistance as the pack voltage increases. Discharging would have similar losses due to DC wiring resistance, conversion to AC, etc.

You can configure the idle consumption of your inverters but even accounting for that, I just have to chalk up the losses to inefficiencies. Many people have suggested getting a shunt but that’s not going to help you on the AC->DC side or DC->AC side.

I’ve run some recent tests in which I’m running in utility/battery priority mode so batteries will only kick in if grid power is lost. For the MTD, I have a total of 300 kWh of load yet grid is reporting 403 kWh. The difference seems excessive for inverter consumption for essentially running in bypass mode 99% of the time so I’m somewhat at a loss.
 
timselectric said:
Solar Assistant only reports the information it receives. Any discrepancy is at the source of the information.
Click to expand...
I know. I didn't mean that.
wattmatters said:
When it comes to measurement of power flows, many inverters:
- don't report self consumption
- are not particularly accurate


This. SA is a convenient means to access, compile, store and present system performance data, but it doesn't generate the data.
Click to expand...
Inverter reporting battery discharge current. The number obviously accounts for the total consumption including inverter itself and all losses. MPPT values are probably fairly accurate. Load is also probably accurate enough. However battery discharge current seems like derived from other values rather than real measurement.
wayne530 said:
I’m not sure what exactly is being measured as “charged” and “discharged” for the LV6548. Is it DC? AC? I had assumed it was DC but other values reported are grid power, load, etc, which are all AC. If it’s AC, I’d expect an AC->DC conversion loss, loss due to resistance on the DC side of the wiring, then losses due to battery internal resistance as the pack voltage increases. Discharging would have similar losses due to DC wiring resistance, conversion to AC, etc.

You can configure the idle consumption of your inverters but even accounting for that, I just have to chalk up the losses to inefficiencies. Many people have suggested getting a shunt but that’s not going to help you on the AC->DC side or DC->AC side.

I’ve run some recent tests in which I’m running in utility/battery priority mode so batteries will only kick in if grid power is lost. For the MTD, I have a total of 300 kWh of load yet grid is reporting 403 kWh. The difference seems excessive for inverter consumption for essentially running in bypass mode 99% of the time so I’m somewhat at a loss.
Click to expand...
It seems like this inverter derives battery in/out amper from other numbers rather than measuring it. ATM we have very low consumption which is around 100wh. Yet After 13 hour of dark 12.4kwh batterys soc down to 73%. Which means 240wh consumption. At sun i also have about 180w difference between pv power and load ( like 80w load and 260w pv power.)
 
alparslan said:
However battery discharge current seems like derived from other values rather than real measurement.
Click to expand...
My clone HS4048 PIP inverter battery current values never lined up that well compared with my Victron shunt. It's exacerbated if the system spends any significant time at low loads as the inverter's current measurement resolution seems limited.
 
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