question

svcg avatar image
svcg asked

MPPT Smart Solar Controller

I have a 110/20 MPPT Smart Solar Controller connected to 2 170 watt flexible solar panels on a sailboat. It has been working flawlessly for 2 years. Last week it shut off and and I can not get it to work. The app says the controller is off due to low voltage from the PV.

I took voltage readings at the solar breaker with the breaker off and get 51.5 V on the PV side and 0 V going to the controller. At the controller I get 13.4V on the battery side and 0 on the PV side.

With the breaker open, I get 13.4 volts everywhere.

The batteries were pretty full so I discharged them a bit and get similar results, just lower battery readings.

The controller has a slow six blinks on the blue light.

I have a spare and am going to switch it out but thought I would check here first.

Any ideas?

MPPT SmartSolar
6 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

kevgermany avatar image kevgermany ♦♦ commented ·
What do you mean by open and off?
0 Likes 0 ·
Show more comments
1 Answer
klim8skeptic avatar image
klim8skeptic answered ·

@SVCG How could there be an array fault if they are producing power?

Power = volts x current.

Your array is not producing power as it can not deliver current.

Somewhere in your panel, or array wiring there is a high resistance connection that is not allowing current to pass.

Mppt's work by drawing current from the panels, the higher the current, the lower the PV voltage. The mppt calculates the power available, and varies the current drawn to achieve the highest power output.

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

svcg avatar image svcg commented ·
Thanks, I should have used the word voltage, not power. It's a simple system, 2 panels with three MC4 connectors. I will start looking for a fault somewhere.
1 Like 1 ·