Solar Controller not working after re-install

short back story
unhooked the solar controller (sunforce 30amp solar controller). been doing work on the van. and today got to hook up the solar again so my house batteries will start charging again.

solar array straight to solar controller. using a multimeter, my 400watt panels are reading 18.89volts, and something like .05 amps (seems low). This was at 5 pm in california, with plenty of light on the panels.
From the solar controller, i have wires straight to my house battery bank.

I hooked up per directions of the solar charger manual.

The solar array is reading the batteries voltage, and thats it. It has LED indicators that show if I am solar charging, and the condition of the battery. None of these are lighting up. 2 weeks ago, with the same setup, things worked perfect. It shows Im getting no current (0.0amp), but will read the battery voltage.

thoughts?
 

autostaretx

Erratic Member
Reading the Sunforce manual, the display can do battery volts and charging current.
But you spoke of using your multimeter to measure the panel voltage and current.
(or was the Current number supplied by the sunforce?)

If you throw a blanket over the panels, does anything change?

No LEDs lit at all sounds somewhat like it's not seeing the battery at all.
But you say it's showing the battery voltage: what IS that number? (the manual speaks of shutting down if the battery is being "overdrawn")

A typical multimeter is willing to read up to 10 amps, so you could conceivably put your meter's current circuit in series with the panels to verify that 0.05. You could also short-circuit the panels with the 10 amp input of your meter to get the real Isc production.
5 pm (even in california) is a fairly slanted sun-angle (well, it's 4pm "solar time") ... i would expect at least an amp, but i'd be a bit surprised if it produced more than 50% of rated output. If there was shade involved, all production bets are off.

I would do the Isc test to verify the panels output ... such as i did one day:

Meter02.jpg
(note where the wires are plugged in ... this was checking the meter with a C-cell and a flashlight bulb before attaching it to the panels)
--dick
p.s. Sunforce manual: https://sunforceproducts.com/wp-content/uploads/2016/11/Model-68032_Manual.pdf
You could also call the vendor.
 
Last edited:

marklg

Well-known member
Does the Sunforce have a procedure for hooking it up (Battery first, then solar panels)? Did you change any settings? My Morningstar will shut down if you change settings with the battery or panels connected. You have to disconnect both and connect the battery first to reset it. Maybe try disconnecting everything and connecting the battery and panels in the order they recommend.

Regards,

Mark
 
Reading the Sunforce manual, the display can do battery volts and charging current.
But you spoke of using your multimeter to measure the panel voltage and current.
(or was the Current number supplied by the sunforce?)

If you throw a blanket over the panels, does anything change?

No LEDs lit at all sounds somewhat like it's not seeing the battery at all.
But you say it's showing the battery voltage: what IS that number? (the manual speaks of shutting down if the battery is being "overdrawn")

A typical multimeter is willing to read up to 10 amps, so you could conceivably put your meter's current circuit in series with the panels to verify that 0.05. You could also short-circuit the panels with the 10 amp input of your meter to get the real Isc production.
5 pm (even in california) is a fairly slanted sun-angle (well, it's 4pm "solar time") ... i would expect at least an amp, but i'd be a bit surprised if it produced more than 50% of rated output. If there was shade involved, all production bets are off.

I would do the Isc test to verify the panels output ... such as i did one day:

View attachment 141843
(note where the wires are plugged in ... this was checking the meter with a C-cell and a flashlight bulb before attaching it to the panels)
--dick
p.s. Sunforce manual: https://sunforceproducts.com/wp-content/uploads/2016/11/Model-68032_Manual.pdf
You could also call the vendor.
I used a multimeter to see what volts the Solar Array was putting out. 18.89 volts. manual says I should read 17-22, so pretty much in the middle.
I partially covered the solar panels while hooked up to the multimeter and it dropped instantly. took the blanket off, and went back to 18.89

the sunforce controller is giving me a reading of the house battery voltage. 12.0 (they have been stored without a charger for 3+ weeks. I suspected they would be a bit down.

I will be calling the vendor tomorrow but figured it can't hurt to ask here.
 
Does the Sunforce have a procedure for hooking it up (Battery first, then solar panels)? Did you change any settings? My Morningstar will shut down if you change settings with the battery or panels connected. You have to disconnect both and connect the battery first to reset it. Maybe try disconnecting everything and connecting the battery and panels in the order they recommend.

Regards,

Mark

yes it does.

First positive wire from solar array to controller, then negative from solar array to controller. then hook up battery, starting positive, then negative.

i did it twice. no difference.
 

vanski

'05 Box Snow Camper
any chance your batteries were at 100% SOC? If yes, they won’t need to pull current
 

autostaretx

Erratic Member
First positive wire from solar array to controller, then negative from solar array to controller. then hook up battery, starting positive, then negative.

i did it twice. no difference.
That's odd ... that order of connection (first panels, then battery) is *exactly the opposite* of every other controller i've ever read the manual(s) for. But it is what the manual says, and the LEDs handle that case.
Most other controllers are dual-voltage .... they'll handle 12v and 24v battery banks. They depend upon the initial battery connection to tell themselves which way to handle the system. If connected to the panels first, the panel's "19v" is ambiguous ... they could be "under-lit" 24v panels, or "full sun" 12v panels (the 24 and 12 in that sentence are "nominal").

So i went back to the manual.
I had noticed (yesterday) that they say that you shouldn't try to change the battery type switch once connected.
They also say that the red LED should be lit if the panels are producing.
Does that light up *without* the battery attached?
If the red LED ain't lit, that would strongly hint that the panel's production isn't getting into the controller.

Does the "battery flat" icon blink as you're setting it up? (i.e. panels connected, battery not connected).
Quoth the manual: "The [___] icon will blink if battery is disconnected from the unit. The charge controller will not
function if not connected to both the battery as well as the solar array. Testing may not be
performed while the charge connector is unhooked from one or both of the battery or solar array"

I'd try the short-circuit with a multimeter current test to see if the panels are really producing (if the controller is not accepting/passing current, the panels will go to their open-circuit voltage (Voc) ... and that can be achieved with very little sunlight). Disconnect the battery, disconnect at least one panel lead, and then place the meter between the panel's two wires.
I suspect you'll see very little current (which could point to panel or wiring failure).

Obviously, the best approach is to get the manufacturers help .. .and then please tell us their recommendations and the results.

--dick
 
That's odd ... that order of connection (first panels, then battery) is *exactly the opposite* of every other controller i've ever read the manual(s) for. But it is what the manual says, and the LEDs handle that case.
Most other controllers are dual-voltage .... they'll handle 12v and 24v battery banks. They depend upon the initial battery connection to tell themselves which way to handle the system. If connected to the panels first, the panel's "19v" is ambiguous ... they could be "under-lit" 24v panels, or "full sun" 12v panels (the 24 and 12 in that sentence are "nominal").

So i went back to the manual.
I had noticed (yesterday) that they say that you shouldn't try to change the battery type switch once connected.
They also say that the red LED should be lit if the panels are producing.
Does that light up *without* the battery attached?
If the red LED ain't lit, that would strongly hint that the panel's production isn't getting into the controller.

Does the "battery flat" icon blink as you're setting it up? (i.e. panels connected, battery not connected).
Quoth the manual: "The [___] icon will blink if battery is disconnected from the unit. The charge controller will not
function if not connected to both the battery as well as the solar array. Testing may not be
performed while the charge connector is unhooked from one or both of the battery or solar array"

I'd try the short-circuit with a multimeter current test to see if the panels are really producing (if the controller is not accepting/passing current, the panels will go to their open-circuit voltage (Voc) ... and that can be achieved with very little sunlight). Disconnect the battery, disconnect at least one panel lead, and then place the meter between the panel's two wires.
I suspect you'll see very little current (which could point to panel or wiring failure).

Obviously, the best approach is to get the manufacturers help .. .and then please tell us their recommendations and the results.

--dick

none of the LED's turn on or blink at any point.

i've contacted Sunforce, and its back and forth email at this point. ill post updates.
 
so

apparently the total distance that the wire from the batteries to the controller has to be 5 feet or less. i was sitting around 12 feet. according to sunforce, this is industry standard..... i had no idea.



can anyone confirm that?
 

marklg

Well-known member
so

apparently the total distance that the wire from the batteries to the controller has to be 5 feet or less. i was sitting around 12 feet. according to sunforce, this is industry standard..... i had no idea.



can anyone confirm that?
I'm calling BS. I've never heard of such a standard. The voltage drop depends on the thickness of the wire and it's length and you can calculate that using the Blue Sea calculator or others. If the wire is longer, it may need to be thicker (lower gauge), but it will work.


The only thing I can think of is that the thickest wire that fits in the Sunforce produces a voltage drop more than they like if it is longer than 5 feet, but you can always splice a short thin wire to a long fat wire and it will be fine. Sunforce should specify the % allowable voltage drop and then you can use the calculator to figure out what guage wire you need for the length you have. If you put 12V, 30A and 240 ft into the calculator, it shows that 4/0 wire will do the trick. I wanted to get to a football field (American Football for those not in the US) but you even 4/0 won't go that far.

Regards,

Mark
 
I'm calling BS. I've never heard of such a standard. The voltage drop depends on the thickness of the wire and it's length and you can calculate that using the Blue Sea calculator or others. If the wire is longer, it may need to be thicker (lower gauge), but it will work.


The only thing I can think of is that the thickest wire that fits in the Sunforce produces a voltage drop more than they like if it is longer than 5 feet, but you can always splice a short thin wire to a long fat wire and it will be fine. Sunforce should specify the % allowable voltage drop and then you can use the calculator to figure out what guage wire you need for the length you have. If you put 12V, 30A and 240 ft into the calculator, it shows that 4/0 wire will do the trick. I wanted to get to a football field (American Football for those not in the US) but you even 4/0 won't go that far.

Regards,

Mark

yea, that seemed pretty crazy to me. i'm using 8awg right now from the batteries to the controller with a ring terminal to fit the controller fitting. the sunforce employee suggested i use 6awg when i shorten the length to 5ft or less. im half tempted to say FU and buy a renogy controller.
 

marklg

Well-known member
yea, that seemed pretty crazy to me. i'm using 8awg right now from the batteries to the controller with a ring terminal to fit the controller fitting. the sunforce employee suggested i use 6awg when i shorten the length to 5ft or less. im half tempted to say FU and buy a renogy controller.
If you put 12V, 30A, 5 ft and 1% voltage drop into the Blue Sea calculator you get 8 AWG. If you go to 12ft you get 4 AWG. You can get rings for 4 AWG without much problem and I use 4 AWG in my charging circuits with much longer wires. So even if the Sunforce needs a 1% voltage drop, 4 AWG will work. If you want to be really sure with the Sunforce, go with 4 AWG at 12 ft.

I looked at a random Morningstar installation manual and they call for 3% voltage drop. Blue Sea says 10 AWG is enough. A random Renogy 30A controller takes 8 AWG max. So Morningstar will work fine with 8 AWG and so will the Renogy. So, my call of BS still stands.

Regards,

Mark
 

HarryN

Well-known member
If you are going to replace it, I would use a bogart engineering model. Very solid setup.

As a practical matter, 400 watts into a low end 30 amp solar charge controller might be a push.

There are some solar charge controllers that are more sensitive to wire / terminal interface details. Some will even go so far as to suggest both crimp and solder. I don't solder, but I do have a pretty high end crimper and am really picky about the wire. These controllers aren't just pumping out power, they also take measurements of the battery behavior to operate the charging details.

If you lived near Livermore, CA, you could just stop by the shop and we could try a few things.
 

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