Solar panel problem/test

[Howie]

I just purchased a 100W solar panel to hook up to maintain the Cougar 5ver batteries when in storage. When placing in the sun the volts show 20v versus the 21.7v max as stated in data so I am assuming that works. However, when testing the amps I am getting a zero or .01A reading. I used two different meters but I am not very knowledgeable when it comes to using them. When I hooked the panel up to my car battery as a test before heading over to the storage unit I didn't see any increase in the voltage and after about 3 hours it actually dropped from 12.24 to 12.12 so I don't understand why. Any technical help would be appreciated.

[GHen]

You didn’t mention if you were running the panel through a controller, I hope you are.

If you are showing less than an amp coming from the Controller to the batteries, it could be sensing the batteries are full so it’s not allowing any power to the batteries or causing an over charge issue.

( I guess I need to read your message again).

[Howie]

yes there is a controller. The lack of amps was being read without any batteries connected. I was just reading the wires coming out of the controller with the meters

[Canonman]

If the controller sees no draw i.e.request for amps it basically sends none, actually it does produce milliamps. There should have been an error code on the controller reflecting the no connection condition. What brand controller/panel are you using?

[Howie]

it is a Coleman 38100 panel with an 8.5A controller. Would reading the meter connecting to the wires coming from the panel before connecting to the controller verify amps being produced and mean it is working?

[B4Keystone]

No. Circuit would need a load to have current draw. Something like a lightbulb.
Voltage is actually a potential reading. With wires disconnected there is a 12 volt potential.
Hope that makes sense.

[Canonman]

Here is the info from the owners manual:
Current Consumption when connected 12V Array
(Battery not present) mA 55 max.
Current Consumption when connected 12V battery
(Array not present) mA 10 max.
So, with no batteries present (load) you won't see any appreciable amp draw. If your multimeter can read milliamps you should see that. Also, if you hook it up to your car battery, there should be an amp reading you can read.
Unfortunately I don't believe this controller (from what I can read in the manual) displays amps; only DC Voltage.
In short, I'd say if you're seeing voltage, you will have amps once the load is applied.

[Howie]

I did disconnect the controller and read v and amps directly from the panel wires and got correct readings so I am pretty sure it is working... I have 2 batteries in the 5ver with the positive from coach going to positive on battery 1 and coach negative going to negative on battery 2 giving 12V. Do I attach the wires from the panel controller to the same terminals and not just the + and - on the same battery?

[Canonman]

Best results will be to connect the controller leads +on one battery and - on the other thereby insuring current flow through both. It will work either way, but I like staying consistent with the existing wiring.
Also, if you're going to run wiring over 10' from the controller to the batteries, use a #10 wire to reduce the voltage drop. Heavier wire should replace the short piece of thin wire that comes with the controller. It's ideal to put the controller as close to the panel as possible or you'll want to use heavier gauge wire there too.

[Howie]

Thank you for the excellent advice, you made my day with your input and the fact that we are fellow S. Jordans is fun. (I moved from S.J. to Henderson so that I do not have to see snow ever again!!)

[Canonman]

I moved from Paradise Valley (Henderson, NV) so I could play in the snow and not bake in the 110
Small World Indeed