Hello,
I would like to better understand more about how the SmartSolar MPPT 85/150 works. Last summer we had a SmartSolarMPPT 85/150 and a BMV-712 installed in our motorhome. We have 5 x 160w panels on our roof, and run 4 6v AGM batteries in a 12v system with a total of 440AH. The settings in the SmartSolar MPPT are custom set to Absorption 14.4v, Float 13.4, Equalization 15.5v.
I am still learning, so please forgive that some of these questions may be very basic. I really appreciate any help or ideas here.
In general, we feel like our batteries don't last as long as they should. So we're trying to test things and figure out if something is wrong with our batteries. We will also try and take better notes so we have something more helpful to share than just a vague feeling.
#1) I was looking at this document... https://www.victronenergy.com/live/victronconnect:mppt-solarchargers And it says, "With regard to the Solar Panel voltage, note that the Solar charger will only operate once the Panel voltage has risen more than 5V above battery voltage." So do I understand correctly that if for example our battery voltage was 12.4v, and the voltage coming in from our solar panels was 17v, that it would not charge the batteries? In this example would the voltage from the solar panels need to be 17.4v or greater?
#2) I have a screenshot from a sunny day last summer. https://community.victronenergy.com/storage/attachments/4488-smartsolar-app-voltage-at-1417.png If I understand correctly, the voltage coming in from the solar array was 16.76v, and the battery voltage was 14.17v, and it says the battery was in Absorption stage. But since the voltage of the solar array was not 5v higher - would it actually be charging?
#3) We disconnected our batteries today. Right after we disconnected them, Battery 1 was at 6.29v, then after 5 hours of being totally disconnected it was at 6.23v. Battery 2 was at 6.30v, then 5 hours later at 6.23v. Battery 3 was at 6.31v, and 5 hours later at 6.24v. Battery 4 was at 6.31v, then 5 hours later at 6.24v. This will sound very silly - but I'm not quite sure what to make of these numbers! :) I am planning on calling the battery manufacturer tomorrow to ask. It seems like it's good that they were all pretty similar. We know the batteries weren't fully charged before we disconnected, and that we may have to do this again. If anyone has thoughts on whether these numbers sound good or bad that would be great. According to the battery manual, these 6v batteries would be considered full at 6.4v or more, and 6.25v is considered 25% depth of discharge.
#4) Is it possible to equalize our batteries too much? In reading the battery manual, it suggests equalizing them at 15.5v for 8 hours. And that you may have to do this 2 or 3 times. Can anyone tell me if it's dangerous to do that too much?
Thank you so much!!