I'm missing something but I don't know what.

[Twotaps]

I have two panels.
1. Grape solar gs-s-250-fab5, 250watt, Vmpp is 30.7v, Impp is 8.1amps
2. Grape solar GS-p60-265-fab2, 265watt, Vmpp is 30.9, Impp is 8.57amps

These are hooked to a midnite classic 150sl.

My issue is that no matter how I hook the panels up(series or parallel), I am not getting more that 21.4volts at the charge controller. It's about a 50 ft run from panels to cc. Voltage drop figures in at right below 4%. This doesn't explain why when hooked up in series I'm only getting 21.4 volts. When I hook each panel separately I'm still getting 21.4 volts. This is in full sun, no clouds, no shading, middle of the day.

Let's suppose for a second that the panels are just putting out 21.4 volts. ... doesn't explain why wiring them in series still puts out only 21.4 volts.

I'm lost, missing something..... something. If anyone has ideas I'd love to hear them.

[littleharbor]

Sounds like your batteries are fatally discharged. I am assuming you have a 24 volt bank??

[Sunking]

What voltage are the batteries? 12 or 24?

If you have 24 volt batteries you must wire the panels in series and you have dead batteries. If you do have 24 volt batteries, check the voltage, bet they are around 20 volt boat anchors.

Or you have a wiring problem. To check the panels is super easy follow this link and check Voc and Imp. .

[Twotaps]

24v bank yes. Panels are currently wired in series.

[Twotaps]

Meter is saying batteries are at 26.4 volts and 94% soc.

[littleharbor]

Do you have other charging sources?
Did you just do something to the solar wiring? I know you said you have tried series and parallel wiring but before you were experimenting with the wiring?
What caused you to notice the low solar voltage?

[Twotaps]

So ive had the 250 watt panel running a 12 volt system for the last year. Just upgraded to 24 volt. New cc, inverter, batteries and added the 265watt panel. Got the system up and running last night but since it was dark i was getting no solar input. Got up this morning excited to watch the voltage rise with the sun but it never got high enough to kick on the cc. Everything else is wired right. Inverter runs cabin off batteries, ac bypass for isolating inverter works, inverter charges batteries like it should when generator is running.

The 250 watt panel is older. Could one off these panels be a positive ground panel? If so would that effect it ?

[Mike90250]

....The 250 watt panel is older. Could one off these panels be a positive ground panel? If so would that effect it ?

What does it's label say, I have no idea.

When you converted to the 24V system, did you reset the Midnight Controller to 24V ?

[Twotaps]

Label doesn't say anything about grounding. I'm just throwing out ideas since I'm lost. The midnight controller is new. Had a different mppt running the 12v system.

[Sunking]

So did you do the Voc test?

[Twotaps]

By the time I got home it was too late. Will have to be Saturday. Just shutting all the breakers off till then. Will report back with readings when I do them.

[Sunking]

By the time I got home it was too late. Will have to be Saturday. Just shutting all the breakers off till then. Will report back with readings when I do them.

Voc test can be done with any light, even inside the house.

[Twotaps]

Fixed......thanks for the help everybody. You got my brain pointed in the right direction. Basically what it boils down to is that I'm a retard. Forgot to jumper the PV negative bus to battery negative bus. I hesitate to even admit that on this forum but eh.... figured ya'll would want an update.

[Mike90250]

Glad it's solved