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.
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.Limited home / battery charging loads seems why as your not sending excess to the grid.
You would need to enable grid sell to have maximum harvest from the solar.
Thanks for the update @Aether. I wondered how your system was doing.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.
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.output from the arrays still seems very limited even though we have a full sunny day with no clouds. I have two arrays and each has the potential of generating around 3500Watts and nearly all my measurements put the volts higher than 430 on each array. You can see in the image below that the volts are hovering around 280 and watts around 800 for each array. Any ideas of a root cause for the limited PV input?
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.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.
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.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.
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.Seems like a serious bug in the MPPT software.
One question, is the Inverter getting very hot when all of this is happening?
That will do it.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.
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.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.
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.
That will do it.
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.Not sure why the battery is charging so slowly from solar...Here are my Before and After shots. I’m not really seeing the PV step up to accommodate the load.
That is just keeping the MOSFETS cool. No big deal.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.
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.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.
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.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.
What about those of us that don’t have MOSFETS to keep cool?That is just keeping the MOSFETS cool. No big deal.
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.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.