question

Tam Ingilman avatar image
Tam Ingilman asked

Understanding how load effects controller input display

So. I would love some help understanding how my charge controller handles and displays data. The question I have is related to charging during BULK operations.


Setup:

In my case I have (2) 200w 12V 10amp panels in series connected in parallel with (2) 100w 12v 5amp panels in series. So generally speaking I expect around 480-500 watts, 40-45V, and around 15 amps. Anywho, the calcuation is not really the question. This system is connected to a single 12V 200ah AGM battery. This is connected to a 100/50 controller. This battery is connected directly to load 24x7. In this case a 12V refrigerator. I've noticed that during the heat of the day, and with just about full sun VictronConnect will show to about 200-250 watts in the gauge and the history will show about the same. Generally speaking its around 45 volts.

Question:

I expect under good conditions this system to put out more like 450-500w out of the 600w listed rated. I checked the app one day during a really sunny day and noticed the system was in BULK. At the time it was only showing about 200-230w. So I connected an inverter directly to the battery, and plugged in a 300w mini heat gun. As soon as I turned the heat gun, the solar gauge immediately jumped to just over 500w in the VictronConnect app, and the amperage to the battery jumped into the 20's. If I turned the heat gun off, the gauge dropped back down to the 200w range.


I don't understand this. If the solar panels were able to produce 500w of power and the system was in BULK, why was it not doing that the whole time? How does a load on the battery affect the possible power available from the solar array? Or is the app not really displaying the power available from the array, but the wattage being sent to the battery. In this case the more power that was drawn the more it sent.

Also, how does constant load affect the controller. It does reach float stage daily.


Thank you!


MPPT ControllersVictronConnect
1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

kevgermany avatar image kevgermany ♦♦ commented ·

Please let us know what your settings are in the MPPT, thanks.

0 Likes 0 ·
3 Answers
Tam Ingilman avatar image
Tam Ingilman answered ·

Not sure what settings you are looking for.

Battery - 12V

max charge 50A

Battery preset is set to "Rotary Switch" position 2

automatic equalization disabled

load output - BatteryLife

streetlight - off

tx port function - off

VE.Smart Networking - not setup



2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

kevgermany avatar image
kevgermany answered ·

Sounds normal.

Assuming panels well illuminated and not wiring issues, charge controller output is limited by what the battery will take. So in bulk mode (max current) the controller allows the battery to take what it will accept. Once the battery voltage reaches the absorption setting, it will switch to constant voltage. As battery State of Charge increases, the battery resistance to being charged increases.

When you put a decent load on the load terminals, the spare capacity in the controller can be used to its maximum.

Sounds as if your battery is fairly close to being charged, but not close enough to cause the controller to switch mode.


2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Tam Ingilman avatar image
Tam Ingilman answered ·

Ok. It sounds like the gauge is not displaying the currently available PV power, just the power the controller is currently utilizing. This is not super clear in there manual. It would be a great addition to the app to have two gauges, one showing actual pv wattage input and the existing gauge showing what is being utilized.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.