Hey everyone
For a small off grid project (IR movement sensor and a connected 10W led light) I bought a 120W PV Panel and the MPPT 75/15 Controller. Those are connected with a 4Ah WET Lead Acid or a 10Ah AGM Battery.
Seems overkill I assume :-) But the thing is, the place for the PV panel is far from optimal. Direct sunlight for only 3 hours max.
I did some Tests today and I observe things I do not fully understand.
The Battery (yt12b-bs) I took from my motocycle was not charged since October 2020 and was quite low (11.78V). The Battery says normal charging at 1A, fast charging at 5A. I therefore kept the basic settings of 5A on the controller and started the process.
After a short time the controller switched from Bulk to Absorbtion later to float. After I disconnected the battery and gave it some time I could watch the voltage drop way below 12.7V.
I played with the settings and first of all set a max current of 1A. Now it spent way more time in Bulk state, eventually changed to Absorbtion and later to Float.
Once again disconnecting the Battery I still saw it fall back lower than 12.7V.
I read a bit about the equalisation mode and thought I'd give it a try. The settings on the controller are still at default (16.2V EQ Voltage) I put everything together and watched the controller.
I'm confused as the Voltage sent to the Battery never reached 16.2V It was stuck at the Absorbtion Voltage of 14.4V I then set the Absorption Voltage to 14.6V and saw the Voltage rise to exactly 14.6V (low amperage of 100mA in Eq mode)
My first question is: Am I wrong expecting to see a equalization Voltage to reach the configured 16.2V? Did I get the Idea wrong?
Secondly: The Voltage on Battery was constantly falling until it hit 12.35V where it stays right now.
Do you think this block is still usable? Oder might it be over with this one?
Thanks in advance
Best Regards
