Post by bupkis on Sept 11, 2019 12:05:36 GMT
When you measure panel voltage you are measuring Voc (voltage open circuit), this is the max voltage of the panel at current conditions but the panel circuit is open and NO power is being made (0A). When you measure amps of a panel, the meter shorts the panel and no power, you are measuring Isc (current short circuit) @ 0v.
Connected to the controller the controller forces the panel to operate @ Vmp, the max power pt, this is usually ~17v or 34v for 2 in series, that is in MPPT mode. In Boost mode the controller is limiting power to keep a certain voltage @ the battery.
It is clear the battery is getting charged due to the 14.1v BT reading (does that match the battery?
I think I would try this, set your meter up for amps. Discharge the battery some. Disconnect ONE panel lead from the controller, wait till high noon, connect amp meter to panel wire and controller terminal and read amps, compare to BT. In Mppt mode panel V should be near 34v and panel amps should be ~5A.
I am always careful measuring amps, Ive blown too many meter fuses forgetting to setup the meter or measuring too high of amperage!!!
In leu of all that can you add a load to the battery and watch the BT to see if more power is made, add more load and the panels should make more to cover the power of the load. Also compare to the controller readout during MPPT mode.
typical IV curve of a panel
at each end there is no power cuz there is either 0v or 0A, the mppt is at the 'knee' of each curve, the top curve represents full blue sky sun directly at the panel and/or test conditions on the sticker on the back of the panel.
Connected to the controller the controller forces the panel to operate @ Vmp, the max power pt, this is usually ~17v or 34v for 2 in series, that is in MPPT mode. In Boost mode the controller is limiting power to keep a certain voltage @ the battery.
It is clear the battery is getting charged due to the 14.1v BT reading (does that match the battery?
I think I would try this, set your meter up for amps. Discharge the battery some. Disconnect ONE panel lead from the controller, wait till high noon, connect amp meter to panel wire and controller terminal and read amps, compare to BT. In Mppt mode panel V should be near 34v and panel amps should be ~5A.
I am always careful measuring amps, Ive blown too many meter fuses forgetting to setup the meter or measuring too high of amperage!!!
In leu of all that can you add a load to the battery and watch the BT to see if more power is made, add more load and the panels should make more to cover the power of the load. Also compare to the controller readout during MPPT mode.
typical IV curve of a panel
at each end there is no power cuz there is either 0v or 0A, the mppt is at the 'knee' of each curve, the top curve represents full blue sky sun directly at the panel and/or test conditions on the sticker on the back of the panel.