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Smart solar 150/70 overcharging at 16.1v

The setup is as follows.

multiplus 3000

280 amp hour lithium phosphate

1 - smart solar mppt 150/70, connected to 2 - 385 watt 48 volt panels

1 - 75/15 blue solar mppt connected to 200 watt 48 volt panel

1 - 100/15 smart solar mppt connected to a 200 watt 48 volt panel

and a overkill 120amp bms


I have manually set all controllers to 12 volts.

I disconnected all controllers by removing the negative wire to the battery. This was in attempt to figure out why the voltage stated on the mppt controllers display via the color control gx was saying max volt 16.1v. Upon disconnecting 2 solar controllers (150/70 and the 100/15 smartsolar) the voltage at the bms slowly went down to 13.5v. I tested the voltage at the output of the 150/70 and the 100/15 and the both said 16v. The charge algorithm is set to lithium phosphate and each device was factory reset in an attempt rectify the issue.

They have been disconnected now for 2 days. I will test again in a bit to see if anything has changed.

any idea what would cause a 16v charge. Equalization is turned off. Manually set to 12v on each mppt controller

thanks

kevin


MPPT ControllerschargerSmart Battery Sense
2 comments
2 |3000

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As a side note. the 75/15 blue solar was charging correctly at 13.5 v
check that the bluetooth network is turned off (for testing) between devices.

and see if that stops the issues you are having, and also turn DVCC OFF, you maybe getting incorrect reference voltages.

so let all the units work on there OWN reference voltages. this does no harm and they will sort themselves out as required when needed.

setting a controller to 12 volts does not set it charge voltages so I presume you have set these correctly as well in each controller. ie to 14.2 absorption and 13.6 float or there abouts.

a full wiring diagram would also be helpfull

a 120 amp bms is NOT overkill AT ALL. it maybe way two small , as a example a 3000 multiplus at full load uses 230 amps (so any load over 1500 watts and the bms will turn off) and upto 460 amps on full overload (not for long though).

you may also find that charging may also exceed the 120 amp BMS as well as a multi on its own can charge at 120 amps plus the solar.

so this could also be a issue if the bms is going open circuit especially on charge.

I would suggest that you get the systems setup professionally checked.


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