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senojev avatar image
senojev asked

MPPT issues

I have two MPPTs, a 150/60 and a 100/30 connected to a 700w bank and a 300w bank. Both MPPTs connect to the house bank via common bus bars . Both MPPTs have identical setups. VictronConnect shows 36A output at 14.4v in absorption for the larger PV bank. No output is shown for the smaller bank which shows float at 14.26v not the 13.2v as set. Voltage readings have been confirmed at the MPPTs as well as current. Cabling from MPPTs to busbars is 6 gauge so voltage drop is minimal.

Ideas on what is the issue is?


MPPT Controllers
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2 Answers
Mike Dorsett avatar image
Mike Dorsett answered ·

As the 2 MPPT are on a common BUS, they will both see the same battery Voltage. If the Float of the smaller unit is set to a lower value than that of the larger unit, or the larger unit has not yet gone into float mode, then the Battery voltage seen will be higher than the float voltage set, and the smaller MPPT will turn off.

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senojev avatar image senojev commented ·
Thanks Mike,


Both MPPTs have identical settings so I do not understand why today with the battery bank at 82% SOC and one controller in bulk outputting around 50A the other is outputting 0 showing float. At 82% with no solar, my Multi charger would be outputting around 80A, significantly more than my 700 watt panels set output indicating that the batteries should be able to accept up to 30A from my smaller controller.

Is there any way around this issue or should I split the bank as I am wasting a third of my panels?

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seb71 avatar image
seb71 answered ·

Better post some screenshots from VictronConnect.

From another thread I saw you also have a third MPPT charger.

What you call "bank" is a PV array.

Bank is used for batteries.


If you disconnect the PV arrays from the other two MPPTs, does the third one start to charge?

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