New to Pv, looking for advice

[Westbranch]

KF did you check the voltages during the time of the load test? 
Both V and A, taken at the same time, gives us information, as well as SG readings. 
Also when doing a load test it is good to monitor the Voltage DROP over time, every half hour or so depending on the rate of load relative to the battery rating 
I did some tests on my NiCd cells every 30 minutes for the first 2 hrs then at 15 minutes for the next hour,  with a .25C load.
What you are looking for is a rapid V drop. Once that happens stop the test. 
Then you compare all cells that have been (equally) tested...

[kf4hzu]

Voltage during the load test was 12.2V and eventually down to 12.1V after a half hour at the battery interconnect junction point (this increased the amps draw to about 26). It started at 12.4V which was due to the laptops being connected to the 175W inverter for several hours after dark. They are AGM batteries so I can't give you SG readings. The load test was done late this evening; where the no-load full disconnect test was done earlier today when the batteries were at full charge.

I'll try individual battery load testing as you suggested after the Classic gets the bank back up to "full" or as close to full as it thinks it is so I am starting at a known charge level.

Any comments about the wire heating?

[vtmaps]

Should I disconnect all 4 batteries and charge them separately?

Which part of my previous replies to this thread are you having trouble understanding?

What you MUST do is separate those batteries and charge them and evaluate them one at a time. 

As I mentioned earlier in this thread, you need to separate the batteries and try charging them one at a time.

--vtMaps

[kf4hzu]

Which part of my previous replies to this thread are you having trouble understanding?

Sorry, it is a lot of information from different people and obviously not all getting processed.

The sun topped off the batteries today, so I will start testing tonight and tomorrow.

[kf4hzu]

I ran some tests with the batteries separated. They all charged up and stayed topped off unlike when they are charged together. They also seemed to discharge at about the same rate with a 5 amp load over 5 hours. What I am seeing with them all connected together must be very small differences in the cables/connectors or the battery internal resistance. I'll try to narrow it down as time allows. For now, I don't think the batteries are too badly damaged yet.

On a good note, I got the parts and time to install a Pv disconnect. I also bought some UL-listed wire for it. So now I am NEC compliant all the way in to the charge controller. Attached is a picture of it. I have one breaker per pole, so when both are opened the panels are completely disconnected. Not sure if this is the right way to do it.

I did have a question about the breakers. Can you install then upside down, or will that cause something in them to fail? Also it says they are rated at 150V but the label on the side says 125V - why?

[Resthome]

I did have a question about the breakers. Can you install then upside down, or will that cause something in them to fail? Also it says they are rated at 150V but the label on the side says 125V - why?

Well I believe those are MN DIN rail breakers and they are polarity sensitive. So they have to be connected correctly. See Ryan's video's

http://www.midnitesolar.com/video/videoPlay.php?video_ID=32&videoCat_ID=16

[Vic]

Hi KF4HZU,

Regarding the two different voltages on the DIN-Rail Breakers.

The manufacturer -- CBI -- has the 125 VDC Rating on the breaker.  MidNite paid to have those breakers tested and Listed at 150 VDC.  For the 150 V Rating to apply,  IIRC,  the breaker must be used in a MidNite Listed box/enclosure.

Regarding the permitted orientation of the MN breakers,  I should not comment.   The DIN Rail breakers do use a magnet to suck-out any arc,  and that function MIGHT require that the breaker be oriented in an upright position with terminals on top/bottom,  and perhaps the front label right-side up.

Did read on this Forum,  that many of the MN breakers could be  oriented in any position,  except with the breaker handle facing straight up ...  will let the someone like Robin comment on these details.

FWIW,  Your installation looks nice,  with good signage.  Have Fun,  73,   Vic

[kf4hzu]

Well I believe those are MN DIN rail breakers and they are polarity sensitive. So they have to be connected correctly. See Ryan's video's

They are! And yep I read the spec sheet before installing them. That is part of the reason I asked about orientation, having them wired with the right polarity using 6 AWG wire pretty much takes up all of the space in the box.

The manufacturer -- CBI -- has the 125 VDC Rating on the breaker.  MidNite paid to have those breakers tested and Listed at 150 VDC.  For the 150 V Rating to apply,  IIRC,  the breaker must be used in a MidNite Listed box/enclosure.

Ah that explains it. Guess I should have done more research! Thank you! Also, that is a MN "Baby Box" in the picture so I should be fine.

Regarding the permitted orientation of the MN breakers,  I should not comment.   The DIN Rail breakers do use a magnet to suck-out any arc,  and that function MIGHT require that the breaker be oriented in an upright position with terminals on top/bottom,  and perhaps the front label right-side up.

Did read on this Forum,  that many of the MN breakers could be  oriented in any position,  except with the breaker handle facing straight up ...  will let the someone like Robin comment on these details.

I'll wait for Robin or someone else from MN to chime in. For now, I don't need to put more breakers in the box so no rush.

FWIW,  Your installation looks nice,  with good signage.  Have Fun,  73,   Vic

Thank you! I am trying to be NEC-compliant and overall safe with the system. Learned a lot on here recently and reading other resources. I'll replace all the cables with UL-listed cable, instead of the welding cable I bought originally, as budget permits.

Edit: The cable I used for the box is rated at 600VDC. It is not very flexible. Any recommendations on cable and where to buy it? I need more 6AWG, need some 4AWG and 1/0 or 2/0 AWG.