The weather forecast for tonight is 'mostly clear' and for tomorrow 'mostly sunny'. After that, the forecasts all include various degrees of cloudy without any mention of sunny. Today, Sunrise is 6:14AM and Sunset is 8:35PM. I want to make the best use of this short window.Here is a list of the components of the solar system:SA. 170W poly as 2 x 85W, 18.3Vmp, 4.69Imp, 22.7Voc, 5.12Isc.TPA. Turnigy Power Analyzer.MPPT. Morningstar Corp. SS-MPPT-15L with temp comp cable.AGM. Johnson Controls 31C 100AH AGMMMS. Magnum MMS 1012 inverter/charger with temp-comp cable. And yes, there are two cables on the AGM!Connected like this:SA -> fuse1 -> TPA -> fuse2 -> MPPT -> AGM -> MMS. The SA is not tilted, plus the driveway is negative tilted to the North.I plan two Voc tests to determine the characteristics of Voc around Sunrise and Sunset.Test#1: At dark-thirty(~5:44AM) I will connect fuse1 while leaving fuse2 pulled. I will record one hour of video of the TPA display. If the Voc has not reached 40V, I will record another hour.Test#2:This is a to be a recording of Sunset Voc starting at 8:00PM until the TPA shuts down due to lack of SA Voltage. Test#3:At noon, I plan to connect the Travel Trailer to the MMS and run the Air Conditioner. The AC is a 5k and usually draws 600W including the 50W fan. Fuse2 will be inserted.Would anyone care to guess how long this might go? The MMS has a 10V LVD. HTH;John

The title says "controller test" but I can't figure out what you are testing for. Maybe I missed something.

With one 100AH battery, I'd guess an AC run of 1-1 1/2 hr. Your AGM will be pretty well discharged with this test.

BFL13 wrote:The title says "controller test" but I can't figure out what you are testing for. Maybe I missed something.Test#3 is to sufficiently deplete the AGM thereby giving the MPPT a chance to produce power. I intend to compare the Kill-A-Watt's reading of WHs consumed by the Air Conditioner against the TPA's reading of WHs drawn by the MPPT.HTH;John

westend wrote:With one 100AH battery, I'd guess an AC run of 1-1 1/2 hr. Your AGM will be pretty well discharged with this test.I'll give you another guess.Keep in mind, with fuse2 in place, the MPPT will be offsetting some of the power used. HTH;John

full_mosey wrote:BFL13 wrote:The title says "controller test" but I can't figure out what you are testing for. Maybe I missed something.Test#3 is to sufficiently deplete the AGM thereby giving the MPPT a chance to produce power. I intend to compare the Kill-A-Watt's reading of WHs consumed by the Air Conditioner against the TPA's reading of WHs drawn by the MPPT.HTH;JohnDo the TPA and the Kill-A-Watt use different constants? Do you suspect something does not match from previous results?You do good tests. I still have the info about AGM and high amp draws in mind that I remind folks about who want to run their microwaves, but only have room/weight allowance for two batteries.

MPPT Solar Controller Driveway Test | Good Sam Community

29 Replies

Salvo
Explorer
Jun 08, 2015
Looking very good! The A & Ah plots are down in the mud. If you right click on the amp & Ah data plot you will get a menue that lets you create a secondary Y-axis. Now you can see what's going on with them. I should have labled the secondary axis as A & Ah.
full_mosey
Explorer
Jun 07, 2015
Sunrise/Sunset - 6:12/20:40 - tests #1 and #2.

Test#1:
2015-06-07, Clear Sky, Vbat 12.6, 2 x 12V fridges ran overnight.

I video recorded the TPA at 6:11 for 26min. The Sun was below the tree line which showed zero Amps and Watts. The Volts ranged from 13.22 to 25.94.

I could see that the Sun was about to emerge so I started another video at 6:38. This second video is 54min. Here is a chart at 6min intervals:

Test#2:
2015-06-06

In Progress

HTH;
John
full_mosey
Explorer
Jun 06, 2015
Line Chart!

Sorry, I don't have charge controller output current.

I don't understand what you mean by "If you have cc input current, that would also look cool to see the difference..".

TPA Ahs and Whs are a direct reading and Hourly values are derived by subtracting each hour's ending reading from the prior hour's reading.

Vmp is derived by dividing Hourly Whs by Hourly Ahs.

e.g.,

15 136 25.301 741.7 4.317 123.2 28.54
16 130 28.29 825.5 2.989 83.8 28.04

At hour 16, Ahs = 2.989 = 28.29-25.301 and Vmp = 28.04 = round(83.8/2.989).

There are no moment in time readings because Watts into the CC depend on panel temp, Sun angle and insolation.

HTH;
John
Salvo
Explorer
Jun 06, 2015
That's looking good. The X-axis should be time. The far left excel column should be time. An option for the graph is to connect the dots. I think that would look better. You can choose a secondary Y-axis for amps. I would like to see charge controller output current. If you have cc input current, that would also look cool to see the difference.

The graph will look something like this.
full_mosey
Explorer
Jun 06, 2015
Is this it?

Scatter - Hourly Ahs, Hourly Vmp

HTH;
John
full_mosey
Explorer
Jun 06, 2015
Salvo wrote:
Graph time vs. amps & Vmp

Not sure you've done this before...
Use XY (scatter) plot
Amps as primary axis & Vmp as secondary axis
Copy graph and paste into MS Paint
Save as .jpg file
Upload to photobucket

thnx

Which Amps, TPA Ahs, or Hourly Ahs?

And, you're right, never done a scatter plot!

HTH;
John
Salvo
Explorer
Jun 05, 2015
Graph time vs. amps & Vmp

Not sure you've done this before...
Use XY (scatter) plot
Amps as primary axis & Vmp as secondary axis
Copy graph and paste into MS Paint
Save as .jpg file
Upload to photobucket

thnx
full_mosey
Explorer
Jun 05, 2015
Salvo wrote:
Don't you want to graph the data?

I'm a database guy, touching a spreadsheet make me feel unclean. :)

What would you like to see in a graph? I do have a photobucket account where I could post a graph.

HTH;
John
westend
Explorer
Jun 05, 2015
Cool, just trying to increase my knowledge about batteries and the effect of appliance draw.
full_mosey
Explorer
Jun 05, 2015
westend wrote:
When will you be able to do the test powering the A/C?

I'm sorry that got started. That would be a test of the Magnum and the 100AH AGM and have nothing to do with the solar array and MPPT.

All I wanted was a method to draw down the battery enough to force the MPPT to draw maximum wattage from the panel. I accomplished that with the 117W draw. That was the objective of test#3. Test#3 was never about the A/C.

I have done tests with other 700W draws, microwave, drip coffee, induction stovetop hotplate to name a few. The answer is 30min with a 100AH AGM.

HTH;
John