EMONPI v3 - After upgrade to Solar system CT from Solar system is showing negative values after certain time of day

Hello all.

I have a question about EMONPI and Solar production after a certain time of day. For months now I’ve been Seeing Solar production in the positive and then reach zero after the sun goes down. Been that way since I set up the system.

I recently purchased a Solar battery and now I have 4 circuits connected to the battery for nighttime use. It’s not yet operational as the install still needs to be inspected. So my system is currently running as before but without the battery operational.

Now sometime around the late daytime, I’m seeing negative values coming from the Solar system which kind of messes with my numbers where before the values were at zero when the system was not producing. I checked the CT’s and they on the same lines at the breakers before the installation but they installed their own CT’s which are connected to the inverter for the monitoring.

My system is a SolarEdge 7600A-US with an LG Chem RESU10 battery. I’m kind of clueless on all this stuff so if this is normal and it’s a config issue or it’s an issue because the battery is not active yet that’s good too. Just curious why the negative numbers.

Thanks

Glen

curious how much into the negative. the inverters consume power at night. so i would assume most likely what ever the newer equipment you installed has just made it more noticeable.

Here are my numbers for the last day…

2018-06-03 18:00:00, 371.0
2018-06-03 18:15:00, -135.0
2018-06-03 18:30:00, -351.0
2018-06-03 18:45:00, -446.0
2018-06-03 19:00:00, -505.0
2018-06-03 19:15:00, -787.0
2018-06-03 19:30:00, -829.0
2018-06-03 19:45:00, -696.0
2018-06-03 20:00:00, -690.0
2018-06-03 20:15:00, -930.0
2018-06-03 20:30:00, -1199.0
2018-06-03 20:45:00, -973.0
2018-06-03 21:00:00, -1022.0
2018-06-03 21:15:00, -1814.0
2018-06-03 21:30:00, -472.0
2018-06-03 21:45:00, -441.0
2018-06-03 22:00:00, -423.0
2018-06-03 22:15:00, -418.0
2018-06-03 22:30:00, -212.0
2018-06-03 22:45:00, -212.0
2018-06-03 23:00:00, -425.0
2018-06-03 23:15:00, -227.0
2018-06-03 23:30:00, -222.0
2018-06-03 23:45:00, -431.0
2018-06-04 00:00:00, -433.0
2018-06-04 00:15:00, -227.0
2018-06-04 00:30:00, -224.0
2018-06-04 00:45:00, -432.0
2018-06-04 01:00:00, -211.0
2018-06-04 01:15:00, -219.0
2018-06-04 01:30:00, -439.0
2018-06-04 01:45:00, -431.0
2018-06-04 02:00:00, -223.0
2018-06-04 02:15:00, -218.0
2018-06-04 02:30:00, -428.0
2018-06-04 02:45:00, -220.0
2018-06-04 03:00:00, -223.0
2018-06-04 03:15:00, -440.0
2018-06-04 03:30:00, -226.0
2018-06-04 03:45:00, -224.0
2018-06-04 04:00:00, -440.0
2018-06-04 04:15:00, -435.0
2018-06-04 04:30:00, -225.0
2018-06-04 04:45:00, -218.0
2018-06-04 05:00:00, -1042.0
2018-06-04 05:15:00, -1004.0
2018-06-04 05:30:00, -1003.0
2018-06-04 05:45:00, -1182.0
2018-06-04 06:00:00, -1186.0
2018-06-04 06:15:00, -879.0
2018-06-04 06:30:00, 33.0
2018-06-04 06:45:00, 204.0

To me it does not look normal. But then I’m so new on this I’m pretty much clueless on what the issue is.

Thanks

Glen

Hi Glen,

We have the option do charge our battery from the grid, is the battery charge % going up? when in a -

Also when our battery is 0% and no solar our units draws a few watts from the grid to keep it powered up

Paul

those are usual numbers. wound seam to be a battery charger option as Paul mentioned. since it a pretty high draw of +500 watt average draw over 12 hrs. or 6kw every evening . also seams weird that it would go into 2 charge cycles over night. as that would mean your battery is discharging for some reason ( considering you say it is currently disabled- perhaps it not fully disabled). what i would do if it has battery charge option disable it. see if that makes a difference, but also once you disable charger, then you need to figure out why the battery is discharging perhaps it working as intended - perhaps you have other issue-- during the day check your battery voltage. mark it down then just at end of the day when the solar panels just stop producing any more power, mark that down. then in the morning before the sun hits the panels again mark that down. not sure what your battery voltage or type, but say it was 48 volt battery normally it would look like this during the the day it would peak at about +56volts. then just at end of day it should be in float charge ~54volts and by morning it might of settled to +52 volts. if it lower then 52 in the morning . ie: ~50volts( lead acid) or say 49 ( lithium 15 series) you have a bad cell in your battery. causing it to cycle charge. ( if lithium battery one or more of your cells just might be very unbalanced you might have to manual balance them or it might balance itself after a couple weeks of usage- check you cell voltage to see if they are balanced if you have that option) if different battery voltage divide the above numbers by 48 then multiple by the voltage of your battery. it should fall roughly with in those number – also could you say what type of battery… lead ( gel, sealed vented) lithium ( type and series)

HI Everyone, thanks for all the information. I’m now just waiting on the Permission to Operate on the battery and then I’ll be able to turn it on and see if the values differ after it’s been activated. This will be interesting. The one thing in all this though is I cannot have the battery discharge to the grid. Huge penalties if the system does that. They actually replace the breakers and hook those circuits into the loads I selected which are directly connected to the battery.

I’ll let you know what happens after I"m able to activate the system and get a few days worth of loads.

One question though. Is it possible to NOT allow negative numbers from the inputs? I can see you can allow but I don’t see a way to prevent negative numbers from being written into the DB.

Thanks everyone!

Glen

Yes. Select allow positive.