New KID install--need help with a couple issues

[AlaskaLarry]

Please excuse the long "lead in" to the issues I am having, but some of it may help to understand my situation and new installation. I have a small cabin in the Alaska Range and it is only assessable by aircraft in the summer and snowmachine in the winter. Approximately 10 years ago I installed one BP Solar, BP275U, solar panel, rated at 75 watts and 4.75 amps,  a small controller, controlling input to a 12 volt battery bank, consisting of 4, 6 volt, golf cart batteries. The load consists of a half dozen 12 volt lights, a 12 volt water pump, 12 volt radio, and a 12 volt electric fence charger. The fence charger is on about 11 months of the year. Also installed a small Low Voltage Disconnect so the batteries would not freeze in the winter, which can reach temperatures of -40 degrees. This past spring, after flying to the cabin, I noticed that the LVD did not appear to be working, and after checking the batteries, I also discovered that 2 of the 4 batteries were no longer charging. These events and a couple others led me to make some changes to the system.

A friend with a neighboring cabin gave me two more solar panels that were identical to the one that I had. Additionally, another friend gave me 2 Caterpillar 9x9730 batteries, rated at 190 amp/hours each. I purchased a Midnite Solar KID controller from a local vendor, and transported it all to the cabin. Prior to installing the new system I tested all three panels in full sun, and they were each developing 21-22 volts.

I wired the three panels in series, so that I could continue to use the existing wire that ran under the metal roofing, a distance of approximately 22 feet from the panels to the controller. The wire running off the roof appeared to be no larger than #14. I installed three new breakers for the array, batteries, and the load. I removed the old LVD, and all of the 6 volt batteries, and cleaned up much of the wiring from 10 years ago, and installed the two Caterpillar batteries, keeping the 12 volt configuration. The only load that was run to the KID was the electric fence charger. All other loads were wired direct to a load center, from the batteries. One of the issues has to do with the LVD, which I'll discuss below.

Everything was installed, following instructions in the KID manual, including inserting the voltage numbers for Absorb (14.55), Float (13.50), and Equalize (15.75), that I obtained from the battery manufacturer. After everything stabilized I kept an eye on the readings and the first "Status" screen showed "4.7A BULKMPPT", and under that "12.4V Solar 60W", The Input screen was showing approximately 54 volts and battery voltage of 12.4 volts. These readings stayed fairly consistent for the next few hours. Unfortunately I had to depart the cabin that evening, and the weather turned bad so I could not get back out for a few days. When I did, the readings were essentially unchanged, even though we were still getting good sunlight on the panels for 4-6 hours during the day.

So, my first question/concern is why was the input wattage so low?? The 60W was the highest that I ever saw on the KID, and it was usually lower than that.  I can do the math as well as the next guy, and it appears to me that if the voltage is approximately 50 volts, and amperage is 4.7, that the wattage should be approximately 200+?!?

The second issue is concerning the LVD. I wired the fence charger directly to the KID + and -. Then followed all instructions in the manual, by turning on the Load. Then set the disconnect at 12.7 volts, so the batteries would not be discharged below that, and set the reconnect at "Float". The problem is, the batteries were still at 12.4 and the Load/fence charger was still on!?! I went to the KID Load menu again and checked all settings, which were correct. So, before leaving the cabin this time, I manually turned the fence charger off, rather than risk running the batteries down. I have spent hours reading posts in this forum, and did locate one person with the same issue, however there did not appear to be a resolution, unless he/she did come up with a resolution, and just did not post it.

Like I'm mentioned, I have spent hours reading forum posts regarding these two issues, in addition to researching many other documents/articles about the first issue. I realize there are several items/areas that could be impacting the readings I am getting--the wire size for the wire off the roof; wiring of the panels; and/or condition of the batteries. One thing I am considering is to wire the panels in parallel, and run a much bigger wire off the roof, in order to boost the amperage off the roof to 14.1 amps and 12 volts. I also realize the two batteries (amp/hours) are somewhat of an overkill for the small load that I have out there. Regarding the batteries, before someone asks, I have not yet checked the individual cells with a hydrometer, but that is on my list to do the next time I can get out there.

I appreciate any input on these problems, and will try to answer all questions, realizing that some of the information may not be available until I am able to fly back out, or snowmachine in the spring!

[TomW]

Larry;

Welcome to the forum!

I wonder if your system just doesn't use up as much % of the power in so it only "needs" the 60 watts to keep up?

If I understand your post you added storage and panels so the system is capable of more loads than you have and The Kid does not see a need to pump power in.

I will poke Ryan on this see if he has more insight if you don't get some replies from the others here. Being a weekend, things can be slow.

I know it is important that things work as expected at remote locations.

Best of luck.

Tom

[AlaskaLarry]

Thanks Tom--

Larry

[Vic]

Hi Larry,  welcome to the Forum.

First,  when you were testing the PVs,  you were measuring the Open Circuit Voltage (Voc)  for the PV at that moment.  Voc is very easy to measure,  but says nothing about the ability of those PVs to deliver power.  You could try to measure Short Circuit Current (Isc),  and this would tell you about the health of the PVs,  under the illumination that they were receiving at that moment.

As you know,  PVs can produce the maximum power available (for the temperature and illumination conditions at that moment),  when they are at right angles to the sun,  with NO shading at all whatsoever  --  shading of any kind will reduce the PV output significantly.

With the KID in Bulk,  the KID is producing all that is available at that time.  In the extreme North,  it is possible that,  with a fairly low sun angle  this might be all that is expected.  In full mid-day sun (sun high in the sky),  PVs can produce about 75-ish percent of the rating of the PV.  This maximum on a summer day with the sun high in the sky,  this maximum would be in the range of about 150 Watts for your three PVs.

The current reading that you are seeing,  is  the OUTUPT current of the KID,  at your battery voltage (12-ishV),  I believe.

You have a nominal 380 Ah (if they are 12 V batts in parallel) battery bank,  but a very small amount of PV power to try to charge those batteries,  especially in far North Latitudes.   Do you have a generator & Charger that might be able to get that large battery bank fully-charged,  and then try to maintain the batts on solar?

With your three PVs in series,  the max string current is only about 3 Amps,  so 22 ft of #14 wire should not be an issue.

If there is any shading at all,  even from a branch,  twig,  bird droppings,  etc PV production can be significantly reduced,  and,  if your PVs are not at a high elevation angle,  at this time of year (like Latitude +15 degrees),  then your solar production may not be too far off,  especially for PVs that have a number of years of use.

Have not used the KID Load function,  so cannot comment on that at this time ...  FWIW,   Vic

[mosolarfan]

1. Are the panels facing due south and set to the proper angle for your latitude, is there any shading?
2. doing the math, 4.7 amps in x 12.4 volts to the battery is approximately 60 watts. kid is reporting accurately.
3.    75 watt panel / 4.75 amps shows a maximum power output at around 16 volts, 16 x 3 for series should be around 48 volts for your mppt or input voltage. the kid seems to be finding it a bit higher which makes me wonder about # 1 above.
4. do an short circuit amps test on each panel to see if they are very near the same,  1 low output panel will drag all of them down in series.

one thing the kid won't tell you is the incoming amps, only the amps going to the battery after the mppt process, I suspect that you are only receiving around 2 maybe 3 amps from your 10 year old panels.
if you are getting good amps from your panels then I would look at the wires to the kid. I would leave the panels in series unless you have a bad one. I have a kid with 125 watt panels on it and I get more amps to the battery in series than in parallel.
hope this helps

[AlaskaLarry]

Well Vic and mosolarfan that is exactly the type of information I needed regarding the numbers I was seeing on the KID. I obviously thought the wattage number I was seeing, approximately 50 watts, was the output of the panels. Now I understand it is the wattage from the KID to the batteries! Understanding that, and looking at the math you both provided, I can see where the KID is probably reporting correctly, given my situation.

Another bit of insight was the information regarding the orientation of the panels, and shading. When I tested the open circuit voltage, they were getting pretty much full on sun, however that was a couple of months prior to the installation. Since that test, we have continued to lose 7 minutes of sunlight a day, or about an hour a week, and the sun is significantly lower in the sky. As a result, there is no doubt that I am not getting even close to the maximum out of the panels. Additionally, depending on the time of day, there is some shading, even though the leaves are off the trees this time of year. I am going to work on the shading issue next summer, by relocating the panels and eliminating some trees.

Regarding the panels themselves, they are at least 10 years old, and probably older, but I just can't remember when I bought mine. When I get back out there next summer, when we have great sunlight, and lots of it, I will take the panels down, and do a short circuit amps test on each one. There certainly is a possibility there is a bad panel in the bunch. At that time, I will reorient the panels on the roof of the cabin in order to get better exposure. That section of the roof is oriented almost due south, but no doubt I can move them to get better exposure.

Regarding the batteries, I do have a generator and battery charger out there and that is a good idea to put them on the charger and give them a boost to full power. One of my concerns from the get go with those big batteries, was that I might not have enough input from those panels to maintain those batteries--like you said, especially at these latitudes, in the winter months.

Thanks again for your responses and I hope I hear something regarding the LVD.

Larry

[Vic]

Hi Larry,

Guess that you have seen this Thread,  regarding LVD (?):
http://kb1uas.com/mnsforum/index.php?topic=2083.0

It appears,  from what Mario said (he was the chief designer of the KID,  I believe)  that one must follow his directions,  exactly,  in sequence ...   again,  I know NOTHING from personal experience ...

FWIW,   Vic

[Westbranch]

If you have so much as a  small finger wide shadow you have to get rid of it.... break out that chainsaw!  Get rid of all potential shade makers if possible...

When you get back in the North,  make the array adjustable so that that your panels are as close as possible to optimum for Dec 21 ie  probably close to vertical ...

good luck

[CDN-VT]

Please excuse the long

The second issue is concerning the LVD. I wired the fence charger directly to the KID + and -. Then followed all instructions in the manual, by turning on the Load. Then set the disconnect at 12.7 volts, so the batteries would not be discharged below that, and set the reconnect at "Float". The problem is, the batteries were still at 12.4 and the Load/fence charger was still on!?! I went to the KID Load menu again and checked all settings, which were correct. So, before leaving the cabin this time, I manually turned the fence charger off, rather than risk running the batteries down. I have spent hours reading posts in this forum, and did locate one person with the same issue, however there did not appear to be a resolution, unless he/she did come up with a resolution, and just did not post it.

So come next year the rest of the critters are arriving & I will need a second fence unit, I was hoping for a brat , but then I want electric gates to control the runs & tractor ways , So i opted for the 3 kid . Im running 1811 FW  & just for grins I fired up the KID & went thru all the settings from this post : 

http://kb1uas.com/mnsforum/index.php?topic=2083.0


EDIT for correction ..
I could simulate the battery getting below my LVD cut voltage 12.5 Vdc & it was still on 11.9Vdc .
I have no PV or charging , just power supplies & meters with a small 12Vdc load of a 8w bulb .

-I see this as a bug , but then again my manual is - 10-268-1 and is not even close on the selections of words .


VT

I re -READ Marios post : Go into menu , load  and pick manual & hit save on every change you do .
use Function Manual and turn it on, then press the SETUP Button to setup the LVD parameters.


It works fine if you use the Voltages for LVD & reconnect , It's the batterys that im trying to protect .
I would like to play with the night light area , but at night I like it DARK .

VT .

[ClassicCrazy]

One way to see what your panels are putting out is to put a big load on the system( turn everything on )  and then see what it is putting out. Like others have said if the batteries are charged up you won't see much going into the batteries.

Not sure if you said your batteries are new or used. If they are very old or have been mistreated they could have a large self discharge - so you could dump a lot of power into them and it won't store very much. Kind of like having holes in a bucket when you fill it with water.

The other thing not sure if you mentioned is if you have the battery temperature compensation hooked up and the correct info programmed into the KID.  The batteries need to be temperature compensated for charging. Temp compensation will raise the  charge voltage as the batteries get colder. Otherwise they never fill up all the way .

If your old controller was not temperature compensating your batteries and you had a load on them that is a sure way to ruin deep cycle batteries in the cold weather. My first lesson !

Larry

[CDN-VT]

+1 CC / Larry
Agree

[mat]

Hi,
Maybe not relevant, but you didn't mention if you did input/output calibration ?

Then, yes, hydrmometer is a good idea (it took me so long to accept ! I don't know why !!!)

[AlaskaLarry]

Well, first, thanks to everyone for their input and comments. I am learning something from every one of them!

Vic--I did see that post that was started by SpokaneTroy, regarding his experience with the LVD function, and his experience was the same as mine. I did go back and checked all my settings, including making sure that the + and - wires from the fence charger go directly to the + and - of the KID. I noted that there did not seem to be a resolution to SpokaneTroy's issue either. So, I am still not sure where to go next with this issue.

I guess I didn't realize that such a small amount of shading can have such a large impact on the output of the panels, so Westbranch is correct--when I pull the panels down next summer to run some tests, and relocate them, I will also break out the chainsaw!

Regarding the batteries, they were used, but not old. However, like I mentioned, the next time I am out there I plan to spend time with a hydrometer and test the batteries to make sure that a bad battery/battery cell is not causing some of my issues. I do have the Midnite Solar temperature sensor installed and programmed into the KID.

mat--I didn't do" input/output calibration" and don't recall seeing anything about that in the manual. So, I guess I have some reading to do!

Larry

[Vic]

   ...   The other thing not sure if you mentioned is if you have the battery temperature compensation hooked up and the correct info programmed into the KID.  The batteries need to be temperature compensated for charging. Temp compensation will raise the  charge voltage as the batteries get colder. Otherwise they never fill up all the way .

If your old controller was not temperature compensating your batteries and you had a load on them that is a sure way to ruin deep cycle batteries in the cold weather. My first lesson !
Larry

Great point,  Classic Crazy Larry,  particularly for unattended systems in extreme environments.

The use of the BTS was on my mental list of things to note in one of the Posts,  above,  but got to the end of writing it,  knew that had forgotten to note that and could not remember just what was left out.

Very good AlaskaLarry that you are using the Optional BTS on your system.

Thanks again Classic Crazy Larry for noting this.      Forgetful Vic

[CDN-VT]

Larry , I got mine to work !
Im using a spare on the lab bench in testing
& learning to move around in the menus , I didn't hit save yesterday .






I re -READ Marios post : Go into menu , load  and pick manual & hit save on every change you do .
use Function Manual and turn it on, then press the SETUP Button to setup the LVD parameters.


It works fine if you use the Voltages for LVD & reconnect , It's the batterys that im trying to protect .
I would like to play with the night light area , but at night I like it DARK .
Hit save always


VT
Edit add , So in seeing I've got the load LVD & kid figured out , Maybe the Brat in 24V could power the electric fence & a gate.
I put the KID back in its box & wire up the Brat as to see if the Brat can also shut off the load . Rather have the Brat stuffed out in the pasture field over a KID .
this is the first time I opened the baox & manual , I check all switches & figure the settings out . 20A cc & 10A load ,12v flooded & in F so LVD . Hook up load light 8w & then power supply 12vdc ,,RE -READ manual & try to find LEDS , I see cover I removed has markings of were the leds are to be on the board.. Dang , a dead Brat . on to the Classic's in follow me & a pair of WB jrs .


VT