Quattrohead
Emperor Of Solar
Yeah that battery is charging very slowly, why is that? Do you happen to have a large load you can turn on for the inverter, then you will see what the panels can do.
PV Voltage Being Limited by my new EG4 12000XP
- Thread starter Joehaynie
- Start date
Just a heads up to people still dealing with this issue. I had my inverter updated yesterday, and it still remained at 120v this morning until I eventually got around to doing a breaker reset. I will update again when something significant happens. It sounds like they will need to push another update with the issue specifically looked at in our case.
Joehaynie
New Member
Got it. So once the load and the battery charging are being taken care of the inverter throttles back the PV power. Thanks for the clarification.
Panels at suboptimal angle, partial shade, old degraded panels. Show us what your panels look like. 851w/285v=3A and should be around 9A. You are not getting full sun on the panels in the moment that screenshot was taken even though it seems like a sunny day.
Joehaynie
New Member
Not sure why the battery is charging so slowly from solar. Probably a setting issue. However, I liked your idea to add a significant load to test out the panels. I plugged in my Prius Plug-in to add load and check the before and after on the PV. Here are my Before and After shots. I’m not really seeing the PV step up to accommodate the load.
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Joehaynie
New Member
I like where you’re going with that. It’s true that my roof has a suboptimal angle. I tried to factor that in when I sized the arrays. There may be partial shade on one or two of the panels at a time because of the low angle of the bare winter branches of a nearby tree. The idea of degraded panels intrigues me. I’ll start dropping individual panels out of the array to see if some are degraded, though I’ll wait until tomorrow since I have too many variables I’m trying to control (e.g. they updated my firmware this morning so I’m waiting until tomorrow to see if that resolved the 120V issue.
There is a lot to think about in this thread. From what I am am gathering and from my lead acid experience, if your batteries are not closed loop, then the MPPT charger will perform a 3stage charge on the batteries, regardless of the battery chemistry and the parameters must be correct for your specific lithium batteries. The battery manufacturer should have the parameters for non-closed loop situations. then a lead acid battery gets very close to fully charged, the PV input to the battery often drops to zero watts, even in bright sunlight. As an example, if you are filling a 2 gallon bucket with water and starting from empty, at first the hose is on full blast. about 2/3rd of the way through, you are more careful and maybe slow down the water nozzle. By near the top however, you are careful to reduce the water down to near a trickle so a not to spill. Same sort of situation for lead acid batteries. As they get near SOC 100, the resistance to accepting more amps in them is much higher.
So the MPPT voltage just may be reflecting a battery near SOC 100 and the battery BMS is refusing to accept any amps. A good way to test this is either to set the inverter to loads first rather than charge first and put some good loads on your system during the day, even in excess of the incoming PV.
Secondly, you could discharge your batteries to say SOC 10% and then see what happens along the way during the day as the batteries charge and reach the SOC 90%. Of course, you will need to carefully follow battery voltage by direct measurement along the way and not rely in the inverter screen.
If you observe the MPPT voltages ramping down as the batteries are nearly fully charged and the load is too small to discharge them much, then I think you may just be experiencing normal behavior.
So the MPPT voltage just may be reflecting a battery near SOC 100 and the battery BMS is refusing to accept any amps. A good way to test this is either to set the inverter to loads first rather than charge first and put some good loads on your system during the day, even in excess of the incoming PV.
Secondly, you could discharge your batteries to say SOC 10% and then see what happens along the way during the day as the batteries charge and reach the SOC 90%. Of course, you will need to carefully follow battery voltage by direct measurement along the way and not rely in the inverter screen.
If you observe the MPPT voltages ramping down as the batteries are nearly fully charged and the load is too small to discharge them much, then I think you may just be experiencing normal behavior.
Joehaynie
New Member
Not really, though when I put it under significant load (e.g. low battery, two ovens and a turkey roaster going at once etc.) the fans come on pretty strong.
That will do it.
Joehaynie
New Member
I’ve started thinking there may be a connection to the battery charge settings. It happens that @Aether (who is also having this issue) and I both have non-standard LiFePo4 batteries so we’re both using the “Lead Acid” setting. The behavior you’re describing makes a lot of sense. I actually brought that idea up to the SignatureSolar guy who called a few minutes ago.
sunshine_eggo
Victron's little biatch
When bypass diodes "activate," they bypass the shaded portion of the panel losing that voltage contribution. If an entire panel is partially shaded, the entire panel's voltage is lost, because keeping its voltage would force operation at lower current and lower array power.
Truth.
Your PV is making all it can make at the moment. 1703+1014=2717w-1880-570=267w/2717w=90.2% inverter efficiency which is normal.
That is just keeping the MOSFETS cool. No big deal.
Quattrohead
Emperor Of Solar
My 13 KW of pretty much ideally placed panels are only managing about 9.5/10 kilowatts max at the moment in Florida.
I have not read the whole thread, and I'm not familiar with the charge settings, but isn't there a "user" setting that you'd use for Lithium in open loop so you can set your charge voltages? Seems using a pre-set lead battery charge profile on lithium isn't going to work well.
Okay, your lithium batteries should have these types of settings to be inserted into a lead acid menu:
AN ABSORB VOLTAGE OF 56.2 VOLTS AND ABSORB TIME OF 2.0 HOURS
A FLOAT VOLTAGE OF 55.8 VOLTS AND A FLOAT TIME OF 0.0 HOURS
A RE-FLOAT VOLTAGE OF 52.4
A RE-BULK VOLTAGE OF 51.4
A LOW BATTERY CUT OUT OF 47 VOLTS ( PREFER 49 MYSELF) WITH A DELAY TIME OF 120 SECONDS. CUT BACK IN A 1v ABOVE THE CUT OUT VOLTAGE.
HIGH BATTERY CUT OUT OF 56.5 WITH A 10 SECOND DELAY CUT BACK IN AT 55.5
CURRENT LIMIT IN AMPS TO THE MAX OF YOUR CHARGER FOR PV OR AC ID NOT IN EXCESS OF THE C1 OF YOUR BATTERY BANK.
ABSORB END AMPS 0
BATTERY EFFICIENCY OF 95%
CHARGED RETURN AMPS OF SAY 5-7.5
YOUR SOFTWARE ON THE INVERTER MAY NOT HAVE ALL OF THESE OPTIONS AVAILABLE. DO THE BEST YOU CAN. THIS WILL PROTECT YOUR BATTERIES TOO.
AN ABSORB VOLTAGE OF 56.2 VOLTS AND ABSORB TIME OF 2.0 HOURS
A FLOAT VOLTAGE OF 55.8 VOLTS AND A FLOAT TIME OF 0.0 HOURS
A RE-FLOAT VOLTAGE OF 52.4
A RE-BULK VOLTAGE OF 51.4
A LOW BATTERY CUT OUT OF 47 VOLTS ( PREFER 49 MYSELF) WITH A DELAY TIME OF 120 SECONDS. CUT BACK IN A 1v ABOVE THE CUT OUT VOLTAGE.
HIGH BATTERY CUT OUT OF 56.5 WITH A 10 SECOND DELAY CUT BACK IN AT 55.5
CURRENT LIMIT IN AMPS TO THE MAX OF YOUR CHARGER FOR PV OR AC ID NOT IN EXCESS OF THE C1 OF YOUR BATTERY BANK.
ABSORB END AMPS 0
BATTERY EFFICIENCY OF 95%
CHARGED RETURN AMPS OF SAY 5-7.5
YOUR SOFTWARE ON THE INVERTER MAY NOT HAVE ALL OF THESE OPTIONS AVAILABLE. DO THE BEST YOU CAN. THIS WILL PROTECT YOUR BATTERIES TOO.
May/June/July panels output 50 kW in a day. November/December 24.5 kW per day. Both in bright sun. About a 25% loss of peak PV output due to sun's angle and the rest due to shorter days.
EG4TechSolutionsTeam
Online Support for EG4 Electronics
What are the configurations of both arrays, and what are the specifications of the panels? Additionally, as mentioned earlier, are the panels currently experiencing any partial shading?
rogerheflin
Solar Addict
On a string ANY shaded panel will significantly effect the entire string. That one partially shaded panel is typically not shaded enough that the bypass diodes activate and that one panel limits the current of the entire string.
When you turned on the above car charger, the solar appeared to be working right (both before and after). The first screenshot showed the solar batteries charging at 1883w, and the 2nd screenshot the charging went down to 443w.
42OhmsPA
Who likes Electrical Gremlins?
Hopefully this gives a good visual of what impacts angle has; photo and screenshot are from yesterday.
(Yes, I know the decks need stained badly; I was to busy with arrays, battery packs, inverters and life; fun stuff...)
(Yes, I know the decks need stained badly; I was to busy with arrays, battery packs, inverters and life; fun stuff...)
@Joehaynie EG4 gave me a new test update, we will find out tomorrow if this fixes our issues.
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