Newbie so please don’t bash me.
This is the setup I am working with. So far I don’t see watts or current even in full sunlight from my panels. I tried different configs., downsizing panel & using mppt 75/15 still nada.. I see draw on the smartshunt but no input.
Am I just too small an array to even dent this 8x6 Trojan 24v bank???
The input panel string voltage must be 5v above the battery voltage for the MPPT to start up, and then 1V higher after that.
What is the Voc of the 100W panels (on the label)?
I’m guessing that two in series isn’t enough voltage to start the MPPT.
You might need to put all 4 panels in series, but make sure the total Voc voltage is less than 100V, or the MPPT can be damaged.
You do have a 24V battery, right?
For charging to start, the voltage from the panels needs to be at least 5V higher than the battery voltage. Are you getting 30+V at the solar panel input to the MPPT. Have you checked with a multimeter. Is the MPPT inadvertently set to 12V. Some more details such as panel specs, screenshots of the MPPT settings, MPPT during operation may help because diagnosis without data is just guesswork.
The panels are getting enough voltage to start charging discounting that.
The MPPT is set up for 24V correctly discounting that.
However, the figures provide the answer. The MPPT is at 26.03V, which is the float voltage so the MPPT is working. The SmartShunt is only showing 24.40V. Therefore, you have a disconnect between your MPPT and your batteries. This can be in either the positive or negative wires. It could be a loose connection, a poor crimp, some insulation trapped in a terminal, a blown fuse, a breaker that is not working etc.. You will have to track this down using the multimeter looking for voltage drop / where the voltage changes from 24.4V to 26.0V.
I hope that you do not have any of the cheap ebay / Amazon DC resettable breakers in the install, these are notorious for giving poor contact.
I have quality BlueSea breakers. I let the batteries discharge a bit to see if that would kick the charger in to gear.. I also manually set the SOC on the shunt to reflect what I was seeing at my Mastervolt display - we have shore MV charger & MV inverter onboard.
My batts were getting low & it was getting cloudy so I quit for today. I will go back thru my crimps & wiring but as everything is heatshrinked & crimped with love & Klein tools as well as a “ABYC pull test” I am at a loss…
The main reason for the solar install is solely to keep up with the fridge when the boat is on a mooring. The fridge/freezer draw approx. 8amps
That is close to the float setting of 26.04V and that reported by the MPPT. If you have no charging current that voltage should be the same as the battery, which was reported as 24.4V.
Hi PW - Thanks for all the nfo. I have charged up the batts overnight, sync’d SOC to 100%, Zero’ current calibrated to be sure. Reset my Mastervolt monitor. I am going to hook up the array which is 4 panels in two strings 2x100 & 2x100 (as noted on my diagram) I will monitor what is coming into the MPPT. I had nothing connected to the output of the MPPT when the aforementioned pic 25.9 was taken.
Thanks again for your repsonses - I have no one to bounce this stuff off of except the manual
