I have a working installation of a BlueSolar 150|35, v1.16, connected to 2 parallel series of 3 250W/24V panels. The battery bank consists of 5 pairs of 2 batteries, each battery a 110VA 12V stationary battery. The system has been working for almost 2 years without any problem. Four days ago, this changed:
- the system did not have power anymore to run a water pump
- because the battery voltage was too low, about 22.5 Volts
- the MPPT was stuck in 'float' mode really early in the day and because of this, never charged to batteries
Yesterday I managed to (re)connect the MPPT to a Linux machine using the VeDirect RS232 connector. Connecting using minicom, baudrate 19200 and 8bits, I got data frames from the MPPT, below a copy of one of them:
This tells me, that the MPPT thinks that the battery voltage is 27320 volts. One minute after seeing this, I measured the battery voltage using a multimeter. Battery voltage is 23,3 volts on the multimeter. The MPPT software seems to stay in float, because of the high voltage it measures.
What are my options ?
- is there a way to re-calibrate the voltage measurement of the batteries ?
- is it safe to re-configure the treshold voltage, set it to a higher value, like 30 or 32V, in the hope that it will go to float when the battery actually has 27 or 28 Volts ?