Victron MPPT, high Voltage reading at night, not reaching absorb during day

[mlsadler]

Hello am having issues with my system, I have 18 panels each 290W wired in strings of 3 panels in series making 6 strings connected to a victron MPPT through a combiner box, at night the MMPT reads a very high PV voltage higher than the batteries yet there is no light, this affects the charge cycle of the MPPT so I never get absorption time at all, what could be the problem20200204_082603.jpg

[Mike90250]

What is the voltage the panels. I need the Voc and the Vmp number from the sticker on the back of the panel.

Voc is the Voltage Open Circuit when the panels are connected to the controller, but not producing power early morning and late evening.
Vmp is the Voltage Max Power for noon time charging

And what is the maximum allowable PV input voltage for your charge controller ?

[mlsadler]

The solar panel specs

Brand Solarworld

Voc 39.9V
Isc 9.97A
Vmpp 31.4V
Impp 9.33A

The solar MPPT specs

Brand Victron 150/85

Voltage 150V max and current 85A max

[SunEagle]

What is the battery system voltage you trying to charger?

With an MPPT CC, 5220 watts ( 18 x 290w = 5220w) is high even for a 48volt system. That 5220w can generate more than the 85amp out rating of that CC. (5220w / 48v = 108.75amps).

Chances are your CC may be having issues do the work you expect out of it.

[mlsadler]

My biggest question is why does the MPPT read high PV voltages upto even 60V in the night while there is no sunshine, the problem that causes is that the MPPT never goes off at night so we get no absorption time the next day otherwise it charges well never has it even ever reached the maximum of the panel power the highest we have ever registered is 4300W, anyway the batteries are 48V 600Ah

[SunEagle]

My biggest question is why does the MPPT read high PV voltages upto even 60V in the night while there is no sunshine, the problem that causes is that the MPPT never goes off at night so we get no absorption time the next day otherwise it charges well never has it even ever reached the maximum of the panel power the highest we have ever registered is 4300W, anyway the batteries are 48V 600Ah

Well that 4300watt is probably the maximum the CC can accept and the rest is just "clipped" off. That 85amps of charging which is being produced is ok for a 600Ah battery system.The battery is seeing a high voltage after being charged but that 60V probably comes down to a resting voltage sometime during the night.

My 12V system shows over 13.5v after the sun goes down but it comes down by morning.