Sorry to start a new thread but I need assistance.
I just emailed tech support because my Classic did not act as expected again today. All day MyMidnite registered about 40-45% of what the array is capable of producing. I understand that this number fluctuates but it was a clear day with plenty of sunshine. It said I went into absorb (28.6v) around 2pm with float (26.6v) 2 hours later. I got home expecting the Trimetric to register a full charge but it had not. It is still showing a -3.39ah loss on the day nor did it register getting to 28.4v and stay there for 2 hours to reset my battery percentage to 100. My absorb is set to 28.6v for 2 hours on the Classic. Additionally, the Classic was again reporting sending out less amperage to the battery than the Trimetric is showing actually going. I did a reset again and immediately the Classic showed a battery voltage of 25.9v and went into BULK MPPT.
I really to figure out what is going on. Can anyone help? Is it something I am doing? Is the Classic no good? Should I try re-updating the firmware?
Quote from: Tons001 on August 27, 2013, 06:37:49 PM
I got home expecting the Trimetric to register a full charge but it had not. It is still showing a -3.39ah loss on the day nor did it register getting to 28.4v and stay there for 2 hours to reset my battery percentage to 100.
You should realize that the trimetric does not reset to 100% just because you have held voltage to 28.4 for 2 hours. You only need to be at 28.4 for a minute while the battery current is below an amperage that you specify.
By the way, the trimetric can show a loss for the day and still meet the criteria for a reset. Also, the trimetric has an efficiency setting (default = 94%) so you may actually put more amphours into the battery than you took out and still read a amphour deficit for the day (until it resets).
Having said all that, I don't know what is wrong with your classic. You said that the classic reported reaching absorb voltage... how high a voltage did the trimetric report for the day? Just because it didn't reset doesn't mean it didn't see the same absorb voltage as the classic saw.
--vtMaps
Trimetric reports 27.6 as the highest voltage for the day. Trimetric H7.1 "Day's Maximum Volts". This after the Classic says it went to Absorb (28.6) for 2 hours.
I had P2 "Charged Setpoint Amps" set to 6 based on my 305ah bank. I just turned it to the default of off.
The voltage from my battery back with all loads off (with the exception of the trimetric) and the Classic off is 26.05 on my Fluke and the Trimetric is showing 26.1. Those are pretty close.
I did notice when I was home with the system the day after commissioning it that the classic went from BULK 27.8 to ABSORB 28.6 in a matter of minutes when it took hours to get from 25.4v to that 27.8.
I am so lost. I am going to try reloading the firmware. Thanks for all the help.
Quote from: Tons001 on August 27, 2013, 06:37:49 PM
All day MyMidnite registered about 40-45% of what the array is capable of producing.
Remember that the Classic will only put out what the battery needs. If your batteries weren't all that deeply discharged, then the Classic may not have needed the full capacity of your array.
At least, that's my understanding of how things work. :P
Thanks. Luckily Midnite Solar is all over their customer service and I have an email thread going with Ryan. I will let you know what we decide. My batteries definitely need it so that is not the issue.
When you see the Classic doing 28.6 volts, measure the battery itself with your Fluke meter and then
the Classic terminals with the Fluke to see if maybe there may be some voltage drop across the
battery wires. The Classic will generally be slightly higher in voltage if there is a lot of current
coming out but in Absorb, it should be very little. Maybe a couple of tenths of a volt.
Also, check your wire screws to make sure everything is tight.
boB
Hi Tons ..,
While this does not apply to the subject of this Thread,
looks like you are using Flooded batteries, based on a pic of your batt bank. EDIT: just went back to look at that pic of the batts, and it is possible that they are Sealed ... hard to see.
Have you checked the specs of the exact batteries that you have regarding recommended charge voltage?
The voltage that you list as your Absorption voltage seem a bit low to me.
If your batteries are Flooded, hope that you have and are using a Hydrometer (or Refractometer) to determine the actual SG of each cell of your battery bank (as they do appear to be Flooded). Battery Monitors must be Calibrated. And there are temperature and battery ageing effects that can cause BMs accuracy to drift over time. Measuring the actual State Of Charge, and then setting the BM to 100% SOC when the batteries are ACTUALLY at 100% SOC is a very good thing to do. AND, then no not rely on the Trimetric as the absolute judge of SOC, but rather a good rough indication of SOC, and as a trend indicator as well. If your batts are SLA, then things are a bit more difficult when trying to Calibrate the Trimetric.
Have reviewed all of your previous posts, trying to determine just which batteries you are using, but all that was found is the pic of the tops of the batteries.
When you get a chance, it may be a good idea if you could write a Signature line for your posts, stating all of the specific hardware for your system, and your IL location. It will help those replying to your posts give more accurate answers more quickly, without asking a lot of questions - some of which seen to not apply to your situation. This will save a bit of typing, too. Thanks, Good Luck, Vic
Thanks Vic.
They are Concorde Sunxtender PVX-3050T AGM batteries. The specs calculate out to Absorb of 28.6 and Float of 26.6. T-Comp of -.5mv.
I will have to figure out why my signature isn't showing up and add some more details.
Hi Tons,
Thanks, my edit to the previous post crossed with your update. The pic is a top-down vies, and it is a bit difficult to see weather the caps are removable or sealed caps.
And being AGMs explains the seemingly low Vabs.
Note that the N AZ Forum has a Sig line, but no specific on the batts.
Thanks, Vic
Now your Sig is quite visible ... am I just BLIND?
Anyway the Trimetric can be calibrated to your batteries either by suing Finishing Amps actually charging the batteries (often speced by the battery mfg), and/or, by resting the batteries with NO charging and NO discharging for 4-6 hours, and measuring the resting V, which is accurate when temperature-compensated.
Good Luck, Vic
You are not crazy ... I went and added it to my profile which must have added it to all my previous posts.
I will further calibrate my Trimetric as soon as possible.
My immediate concerns is that something is wrong with the Classic. I did a reload of the firmware last night to see if something went screwy when I updated it before commissioning the system on Sunday. Unfortunately, it is not a sunny day here so I am sitting at the 26.5v in bulk so the Classic is not exactly getting a workout. That and I am not at home today so I can only monitor from MyMidnite.
I am going to trace the battery voltage from the bank back as Bob and Ryan requested.
Fron what ive read of your thread, i would say, relax man, nothing seems to be radically out of order. A few tenths of a volt here or there betw products is nothing to lose sleep over. Lead acid voltage does increase sharply at the end of bulk stage, thats normal.
If you want to really see what the panels can do wait til a couple of rainy days followed by a sunny day. If your loads are enough to keep it from floating too early, then its is a good time to go measure everything up with clamp meter.
It was more than a few tenths of a volt.
Thanks to Ryan, Bob and Mat ... we got everything corrected. The Classic had to be field calibrated and appears to be working like a dream at the moment. Midnite Solar has about the best customer service I have ever experienced.