I have a classic 150 that doesn't seem to be charging.
Setup:
12 Jikno JKM410M-72HL-V panels wired 2 in series by 6 parallel, produces just shy of 5kw full sun.
MNPVCombiner box with 15 amp breakers for each string.
Classic 150 with whizbang.
4 strings of Rolls L16 445 (yeah I know one string too many. 1800 AH capacity array is facing dead south at a fixed 60 degree angle, this time of year averages 5-6 hours of sunlight
constant load of 350watts
Remote IP monitoring of the Classic, and Conext inverter.
The site is at 7300' on top of a mountain. For the last couple weeks the site has received about 4-5' of snow, I have couple cameras to monitor things outside.
It would snow for a couple days then, get sun for a few days and repeat. trouble is the storms kept stacking up and I wasn't getting enough sun and they continued to discharge to 30%.
The Conext inverter and the LVDC are programmed to disconnect at 44 volts and don't come back on until the batteries get to 48 volts.
After the latest rounds of storms, the Classic wouldn't charge when the sun came out. I do have a camera on the back side of the panels but not one facing the panels (ugh). For 3 days I would watch the PV voltage on the classic come up to 97 volts all day, the charge current would fluctuate between 0-.2 amps. At night I would see 14-15 volts on the panels (leakage). The battery bank voltage steadily declined until it got to 44 volts and then the Inverter and LVDC did their job.
I considered rebooting the Classic in the configuration menu in the monitoring app but was afraid it would have reset the classic and I wouldn't be able to access it remotely any longer.
Usually, it takes one good day of sun to melt the snow and ice after each storm. I am on day 5 and nothing. The site is only access by snow machine this time of year so I won't be getting up there anytime soon.
Should I have rebooted the classic in the App?
Any ideas why I am seeing good input voltage but now current?
I have configured the Classic to charger all the way down to 36 volts?
Last I saw the batteries were sitting at 2degree C. They are inside an insulated box inside the building.
Hi there.
To trouble shoot this, we need to know what the PV input voltage is sitting at as well as the battery voltage voltage reading.
Maybe you could take a picture of your screen ?
Have you looked at the RFR or Reason For Resting number or message ? I assume you are monitoring by way of the "Local App" ?
Resetting the Classic should not keep it from communicating. I do understand your hesitation in doing that though.
If there is a lot of snow on the panels, maybe the Classic tries to turn on and charge but not enough power comes through so it goes back to resting ? The RFR number or message on the local app should provide some good information.
boB
PV input voltage during the day 96 volts (max) and night 15 volt
Batteries were at 44 volts (I no longer have connectivity because the LVDC and Inverter cut out at 44 volts).
during the day the App shows the charger is in "MPPT Bulk Mode", sits there all day until the sun goes down.
OK, good. Sitting in MPPT mode during the day. I am sure that it is turning off and back on and trying again every minute or two...
So, if you are seeing 96 volts maximum, I am assuming that is Voc or open circuit voltage ?
Here's the big question... Do you ever notice the PV input voltage coming down when in MPPT and then you see a higher voltage when the Classic is resting for several seconds ? And what is the difference in voltage ?
What is your Absorb voltage set to ?
boB
As for VOC I would say yes. The panels VOC is 50.4/panel. I have rarely ever saw more than 98 volts on the CC.
Yes regarding the voltage coming down. The array seems to like 82 volts MPPT. I have had days where it is full out put 85 amps at 82 volts. Each panel MPV is 42.3 V
the classic resting (when in float) voltage is usually 91-92 volts.
Absorb is set to 60 volts.
temp comp -5mV/c is turned on too
If Voc is about 100V then MPPT voltage (Vmp) should be around 80 volts, give or take a bit so 85 might be OK.
If Voc is specified to be 50.4V at 25 degrees C then real Voc in cold weather would be even higher.
So, is there snow on the panels ?
boB
So that is the million-dollar question? Unfortunately I can't see them! I ran out of time and didn't get a third camera installed to look at the panels this fall!
Like I said in a previous post it usually takes a day of good sun (which we have had several now) for the snow to melt/slide off.
Bob I think you might have answered my questions about are things normal, are the voltages I am seeing and the manner which the classic is functioning.
I had a similar problem last year. Except I didn't have and LVDC's in play. long two-week snowstorm, lots of snow no sun. after the 9th or 10th day the batteries were 100% discharged. by the time I got up there this spring the batteries were sitting at 15volts. It was a single string of rolls 445 L16 load was 2 amps continuous.
I pulled these batteries put in 4 strings of L16s and hoped for the best. and did add LVDC and disconnect params on the inverter.
I know the solution is to add a genset, which is sitting out in my garage getting set up to be off grid. No one ever told me this was going to be easy!!
Could you have an auxiliary battery that is kept at float all the time, but will switch on if the main battery disconnects ?
You would need something to keep the Classic on so it could start charging if and when the snow finally melts .
Some of the new lithium batteries have internal heaters so that if they shut down charging from cold they are supposed to send the pv to heaters first until they warm up enough to start charging again.
But they might not work for you if they stay on discharge at lower temps - would still drain down to low voltage cutoff. Maybe some are programmable. I don't have any experience with them.
I have an idea that would be nice if it worked. Something like a blade or sweep that runs on rails on side of pv array so it could clear some or most of the snow off the panels.
Larry
Well it would have to be a 48 volt battery I suppose. Part of my reasoning for setting the LVDC at 75% SOC was that it should leave enough power in teh batteries with the loads disconnected that when the snow finally did melt the CC would still be on. Or so that's the thinking.
The real fix is for me to get this generator installed. Batteries get to 50%SOC Genset kicks on and runs them up to 90% SOC. repeat until the sun comes out. only 90% because I have to try and Strech the fuel to last all winter.
The current loads draw 10% of my battery's capacity every day. During the spring summer and fall (well not snowy fall) this isn't an issue. usually, batteries are 100% SOC with in 2-3 hours of first sunlight.
Also adding a second smaller array on the east side of the building next year. Only 2.5Kw but set at 70 degrees, looking for that first morning light and low angle sun in the winter. They will be shaded by midday anyway hence the steep angle, oh and yeah shed that white sunblock too!
What are you using for SOC control ? The Classic Aux contacts ?
Larry
Sorry Larry what do you mean? I use a victron 48 volt 100amp LVDC for the DC loads and the SW4048 has its own internal configuration. is that what you are referring too?
Quote from: MountianComm on December 19, 2022, 02:43:46 AM
Sorry Larry what do you mean? I use a victron 48 volt 100amp LVDC for the DC loads and the SW4048 has its own internal configuration. is that what you are referring too?
I was wondering what was determining the SOC. Sounds like the victron does disconnect based on voltage. SOC percentages are always just estimates though I know the Classic Whizbang does a pretty good job in that it will calculate in the temperatures too.
Larry
I guess I need to ask this straight forward. At what battery voltage will the Classic 150 (Configured for 48V)shut off?
Clearly it is above 44.9 volts, which was the last recorded voltage before my Classic 150 went offline.
And at what voltage will/should it turn back on?
I am not the only person who has experienced this problem. A fellow cohort with a similar system suffered the same issue.
Jim
The Classic should continue charging and running well down to less than 10 volts battery.
What is your PV input voltage ?
If it is resting all the time even with high enough PV input voltage, you can look at the "Reason For Resting" (RFR) number to get a sense of what might be happening...
From the main status screen, hold down the left arrow key and then tap the enter key while that left arrow key is being held down. You will see a screen with some numbers on it. The RFR number is on the very top line in the middle.
That RFR number right after the Classic being turned off and back on again with the circuit breaker will be 100, 101, 102 or 103.
In the meantime, I will find the list of numbers and their meanings
boB
Hi boB,
If needed, here is a Link to RFR, how-to, and RFR List from the Classic Knowledge Base
https://www.midniteftp.com/support/kb/faq.php?id=72
FWIW Vic
Vic and Bob thank you for the replies. I hope to be visiting the site sometime before march. the local SAR team went up there and sent me photos of the array. absolutely clear no snow. so still a mystery why the classic won't charge the batteries.
Jim
Jim, thank you for the picture of your beautiful comms site !
Are those Classics plugged into the internet for monitoring ?
Did you say that the PV input is OK ? Meaning, not zero volts at least and PV input voltage not over 150 V DC ?
boB
Hi Jim,
Thanks for the pic.That is a beautiful installation.
Too bad that the inverter LVD, shut off your ability to monitor and control the Classic.
I have nothing to contribute, at this point.
Good Luck, Vic
sorry for the delay, just a matter of what iron is in the fire at the time.
Correct plenty of voltage from the panels, 97 volts to be exact.
All this snow we have had this month has really put a wrench into getting to the site. hopefully sometime next month!
thank you for the complements. Yes the snow does make the array look nice! We would have done bifacials but getting ones that fit the existing racking last fall didn't happen, it was hang the Jinko 410's or stick with the the old Sharp 167's that were starting to show their age in production. Obviously, we went with the Jinkos.
Was that all helicopter delivered building materials? must make for expensive building per square foot.
Quote from: MountianComm on February 16, 2023, 11:08:52 PMI guess I need to ask this straight forward. At what battery voltage will the Classic 150 (Configured for 48V)shut off?
Clearly it is above 44.9 volts, which was the last recorded voltage before my Classic 150 went offline.
And at what voltage will/should it turn back on?
I am not the only person who has experienced this problem. A fellow cohort with a similar system suffered the same issue.
Jim
You mention going off line, If the Conext shuts down on LBCO the internet goes away correct? Classics (As boB pointed out) should run down to 9-10vdc on the battery side. In my 15 ish years I have never seen one shut down in the mid 40 volt range as they are designed to charge a 12v battery as well.
Quote from: MountianComm on December 16, 2022, 04:49:27 PMI have a classic 150 that doesn't seem to be charging.
Setup:
12 Jikno JKM410M-72HL-V panels wired 2 in series by 6 parallel, produces just shy of 5kw full sun.
MNPVCombiner box with 15 amp breakers for each string.
Classic 150 with whizbang.
4 strings of Rolls L16 445 (yeah I know one string too many. 1800 AH capacity array is facing dead south at a fixed 60 degree angle, this time of year averages 5-6 hours of sunlight
constant load of 350watts
Remote IP monitoring of the Classic, and Conext inverter.
The site is at 7300' on top of a mountain. For the last couple weeks the site has received about 4-5' of snow, I have couple cameras to monitor things outside.
It would snow for a couple days then, get sun for a few days and repeat. trouble is the storms kept stacking up and I wasn't getting enough sun and they continued to discharge to 30%.
The Conext inverter and the LVDC are programmed to disconnect at 44 volts and don't come back on until the batteries get to 48 volts.
After the latest rounds of storms, the Classic wouldn't charge when the sun came out. I do have a camera on the back side of the panels but not one facing the panels (ugh). For 3 days I would watch the PV voltage on the classic come up to 97 volts all day, the charge current would fluctuate between 0-.2 amps. At night I would see 14-15 volts on the panels (leakage). The battery bank voltage steadily declined until it got to 44 volts and then the Inverter and LVDC did their job.
I considered rebooting the Classic in the configuration menu in the monitoring app but was afraid it would have reset the classic and I wouldn't be able to access it remotely any longer.
Usually, it takes one good day of sun to melt the snow and ice after each storm. I am on day 5 and nothing. The site is only access by snow machine this time of year so I won't be getting up there anytime soon.
Should I have rebooted the classic in the App?
Any ideas why I am seeing good input voltage but now current?
I have configured the Classic to charger all the way down to 36 volts?
Last I saw the batteries were sitting at 2degree C. They are inside an insulated box inside the building.
As one that has lived in snow country all my life (Well ok except the last two winters) I can tell you VOC will show up on snow covered panels. Not saying this is what it is but I am saying its possible the panels have snow or ice on them. The fact you saw some amperage makes me think the classic is ok. What did the PV Voltage do could you watch it sweep down to battery and then pop back to some voltage in between VOC and Battery?