On overcast days my solar panels cannot charge victron batteries to 100%.. I use them until low battery warning light flashes and I then turn on AC mains power to try to charge the batteries, sometimes as low as 20vdc. It’s a 24vdc system.. the fan does not come on, and the unit cycles on and off every minute or so.. I thought the unit can charge at 120 amps ? It goes into BULK charge for a minute or so and then low battery and overload leds illuminate, and then shuts down for 20 seconds and reboots and does the whole pattern again..