Reading AMPS from a solar panel

Keep after it Robert! I, too, like the NASA approach (pre1970 :B)

Got it all wired up!

Here is a picture of the shunt mounted next to the solar controller:




I had to cut out a small wooden panel to mount the meter as there was a cigarette lighter jack here previously and the meter wouldn't cover the hole:


This is a picture of the shunt for the Trimetric 2025RV battery monitor. Notice the piece of copper tubing so I can run my Black and Decker charger through the Trimetric and record the amp load. (Thanks BFL)


This photo shows that the B&D is feeding the battery 2.8 amps and the solar panel is outputting 19.2volts but because it is in total shade, there are zero amps coming from the solar controller. Volts are read right from the wires of the panel and the amps are read from the Morningstar controller.


This picture is showing the battery is at 98% capacity. The SunPro analog meter is simply reading battery voltage.


This picture is showing the battery is at 14.6volts. The green LED at the top of the Trimetric is showing that the battery is being charged:


I ordered another V/A meter and I'm going to install it to read Amps and Volts from the panel and the second one will read Amps and Volts from the solar controller.

These meters are only $18 so, what the heck, I'll get this truck camper to look like the space shuttle one way or the other!...:B

Rbertalotto,
That is unfortunate as it works great with my Sunsaver. Different model I guess.
You could monitor solar output voltage via the B2 switch on the Trimetric (I do this as it's faster than navigating through the Morningstar Remote menu)
To measure solar panel current you could put a second Trimetric shunt resistor in series with the solar panels, and then measure the voltage across the shunt to determine panel current (current = volts/resistance).
Steve

Maybe this has already been suggested, but why not use the Morningstar Remote Meter to monitor your panels

Unless I'm missing something, I don't believe that panel will work with my controller.

Step 5
Connect one end of the RJ-11 meter cable into
the RJ-11 connector on the controller or
inverter. Route the cable from the c
ontroller or inverter to the RM-1.

No RJ11 connector on the SunSaver controllers....

Rbertalotto,
Maybe this has already been suggested, but why not use the Morningstar Remote Meter to monitor your panels and leave the Trimetric for battery monitoring.
Steve

You can test the output by connecting the panel to a battery who's in need of a charge. Place the panel in optimal sun exposure. Using a multi-meter one can test the "load" being placed on the panel. The reading will never exceed the panels max-out rating but until either the sun goes down or the battery reaches a full charge the output load reading from the panel should be just at or just below it's max-out rating.

I won't explain how to use a multimeter but I will say that most offer settings for reading the line load. The directions that come with the meter will give you the proper settings.

When there is more than one charger on, they do amps based on their relative voltage spreads compared with the battery voltage. The converter at 13.8v and the battery at 13.8 or more from being on the 14+ voltage charger, will not have any spread to make amps, so the higher voltage charger does it all.

If both are above batt voltage but one is lower, it will do fewer amps than the higher one of the total and the lower one will taper its amps first as its spread shrinks.

The batt can only accept so many amps, so if one charger can do it all, there is no point in having more. eg, if the battery acceptance is 20 amps and you put two 30a chargers on, each will do 10a. Yank one charger and its amps will jump from 10 to 20.

With the higher voltage charger removed, the battery voltage has to fall back (takes time) to below the lower voltage converter's for the converter to have any spread again so it can make amps.

EDIT-scrub the following, since the converter will do it never mind its charger portion. needs some other way to have a load on the battery not supplied by the converter part. Hmmm. A small inverter clamped to the battery bank with a couple 120v lamps plugged into it?
something.

To see if the converter can make its 6 amps, just plug in so the converter is on, and turn on two lights (-6a) and the Trimetric should show a net near zero. Or to be more clear, turn on three lights and now the Tri should show -3a with the converter doing +6 (derived, not showing).

OK...Just went outside to try a few things.........

First, hooked up the B&D charger as BFL13 suggested. PERFECTO! The digital readout on the charger said 1.9amps and the Trimetric recorded +1.7...seems accurate enough for government work. I would imagine this number is 1.9 minus the parasitic drain fro the alarms etc. The Trimetric showed the battery at 100% and the "chargeing" LED was illuminated.

I then disconnected the B&D and connected shore power, the Centurion converter registered .9 AMPs and showed the battery at 100%. So it seems the "Mighty" centurion was only putting out .7amps??? The tag on the inside of the Centurions panel says it should output 6amps. Is the output on this 1998 vintage converter regulated?

Now when I connected the B&D AND the Centurion, the centurion stopped working. The fan shut off, no fuses blew, no drama...just stopped working. When I removed the neg clamp from the B&D that was connected to the shunt, the Centurion started back up.......Interesting?

I wonder if this will happen when the camper is in direct sunlight and the Morningstar is outputting its max current?

:)

Please clarify. Have you ever plugged your camper in so the converter is working, and then seen what the Tri is showing?

Excellent question.......No I haven't. Until your last post I hadn't realized that the Trimetric would also register other charging sources.......As the kids say.."Dah!"

I'm going out now to see what happens AND to hook the B&D charger as you suggested.

Thanks again....I owe you a steak dinner if we ever meet!