Morningstar 30amp solar charger display

MrWizard wrote:
Both
It is what is going into the batteries
You might have 50 amps solar capacity under ideal conditions
But if if the batteries don't need it then they are not going to take it
Also early in the morning the batteries will be hungry, but the panels won't have enough sun to produce full power
So all they can produce is a few amps

So yes the panels are producing 7 amps not more , only 7 because
That is either all they can produce at that moment or because that is all the batteries will accept
That IS the amount being produced and sent to the batteries

+1 I have monitored ours, CC output = solar panel output, measured with clamp on, = Trimetric reading.

red31 wrote:

MrWizard wrote:
...OUCH

ain't that one of the controller's job, to limit panel energy production when it is not 'needed'.

controllers JOB .. is to control Voltage
the amount of current in the circuit is a function of voltage/resistance

as the battery charges, it's internal resistance increases, so current flow will drop, increasing to voltage to set limit allows the battery to keep accepting charge current

the OP asked if the 7amps being shown on the controller was all the batteries would take, or what the panels were putting out

the answer is YES to both questions
it is NOT an either or situation
it is "that is it" situation

it might be the middle of the day, and the batteries nearly fully charged, so that is ALL they will accept (aka all that battery resistance will let flow thru the circuit into the batteries) so that IS what the panels are putting out , until the circuit resistance changes, by turning on some power using device (aka load), when another load is added, circuit resistance is lowered and current increases up until it reaches the limit that the Solar can provide

or the other possibility is that the batteries are Not yet charged, but the sun is low and that is all the solar panels can produce, and the batteries are taking all of it

but it is still the same answer
yes that is what the panels are producing, yes that is what the batteries are getting

example
in the morning, my batteries are low (all eight of them) and can easily accept over 100amps
but the solar conditions can only supply a few amps, and that is what the controller will show

i can start the generator put my clamp on meter on the converter charge wires and read over 100 amps
the solar will still show the same few amps because the batteries can take all that can be supplied, and that is all the solar can produce until the sun gets higher, as the sun gets higher the solar increases until it reaches the limit the solar can produce or the limit that the batteries can accept,
but what ever is on the meter IS what is being produced and going to the system, it is voltage vrs resistance
and the meter will change reading every time the fridge cycles something is turned on or off

smkettner wrote:
PWM controller, the panel and battery amps are the same.

Yes, if there is no load.

Panel amps = controller output = battery amps + load amps.

Leaving testing aside, - how input current of PWM controller can differ from its output current? Assuming that everything is wired correctly.

OP didn't ask about "maximum current available" at any given moment, or a maximum current possible at perfect conditions.

MrWizard wrote:
...OUCH

ain't that one of the controller's job, to limit panel energy production when it is not 'needed'.

Was there a misunderstanding here ?
Like PTs post, I test my 18 amp (max full sun) system by loading the batteries w/ a 50 amp carbon pile load. If I see 14 to 16 amps, I know everything is operating at max amps available. Maybe me that didn't understand Wizards post

MrWizard wrote:

pianotuna wrote:
It is fairly easy to test this. In good solar conditions, turn on a large load. If the display shows a larger number--then you know it is set to measure what is leaving the charge controller, and not what is coming in.

sorry PT
yes the load might show an increase, but
the controller ALL ways shows what is being produced and sent to the system
NOT what might be available,
think about the electric meter on the side of the house
it shows what you are using
NOT the MEGA WATTS available on the utility power line

if the batteries and house circuits only take 7amps, them that is all that is being produced, not 30amps , that extra difference is
"Potential Power" not being produced or utilized
if it was being produced and not used the controller would be dissipating it as heat...OUCH
it is voltage VRS battery circuit resistance , which limits the flow to 7 amps, even if more is available

if you turn on a load and it goes up then more is available
if the flow does Not increase, like late afternoon or early morning, then that is all the solar energy available

but always the meter shows BOTH... what is going to the system, IS what is being produced

OP - in case if waters got too muddy - your display shows "controller output". The total of current going to battery and to loads. Current going to battery can be lower than what it "can accept", if there isn't enough sunlight or the loads are stealing the current.

With PWM controllers this "output" is practically identical to "controller input", minus very low self-consumption current needed to feed the controller itself.

Peak output of the panels (and the controller output) could've been much higher or lower few hours earlier, but you wouldn't know this if you weren't looking at it at that time, because Tristar display is very basic. Despite the cost. To see daily output graph you need to buy the adapter for monitoring this on laptop. Not terribly important.

PWM controller, the panel and battery amps are the same.

MPPT controller, there is an option to see either/both.

Dat's why I put another meter in the system, right on the panel. Or more correctly on the controller input terminal.

One morning bright and sunny I got up and found the panel voltage suspiciously low. A turkey vulture had landed and spread its wings to dry...

Hi Mr Wizard,

Yes it shows both what is being used and any extra that is being stored in the battery bank.

The OP wanted to know if it showed what the panels were producing. It does not do that, so far as I understand.