Good day, I have two Multuplus 48/5000/70. They have been connected to my 150/100 mppt with 4 Leoch 48V 15 cell batteries,and working beautifully for the last 2 years. We’ve recently added more solar panels and a 250/100 mppt. I used the battery parameters from my 150/100 and used it for the 250/100. The 2 solar Chargers are working great together, now the problem is they stay between absorption and bulk and don’t go into float. SoC is 100% and I’ll hear my battery relay open and closing because mppt still wants to send power. I’ll put a screenshot of my shunt and mppt . Please advise if you could, what to change so my mppt’s will go into float. Thank you
Your float voltage looks to high for a 15 cell lithium iron phosphate battery, it is still in the charging voltage range. I would expect a float voltage of somewhere around 50.6V, just below the resting voltage of a 100% full battery.
What may be happening is you come to end of charge and the voltage drops. The charger will go back into bulk if the battery drops 0.4V below the float voltage. As a full 15 cell battery has a resting voltage of 51.0V you will always drop below the rebulk voltage of 52.6V (53.0 - 0.4).
Dont forget to disable temperature compensation.