question

stevemc avatar image
stevemc asked

Single PV with 2 x MPPT's.

Setup is one solar panel 330w into two MPPT 100/30’s, and then two separate battery banks.

The theory was that the two MPPT’s would simply take what they needed from incoming available power from the solar panel and distribute to each battery bank per demand.


Practical result is that the two MPPT’s appear to be fighting each other.

Alternately each MPPT takes and distributes full available power for about 4 seconds before dropping to zero as the other MPPT then takes full available power for about 4 seconds. The cycle repeats indefinitely.


Attached photo of setup.

Solar is 1 x 330W 34V panel

This is connected to both MPPT’s in parallel via 16A CB’s at top in photo

MPPT’s then go separately to Winch and House batts via separate 40A CBs at bottom in photo.

Winch batt is 200AH 12V AGM

House batt is 400AH 12V AGM



A separate issue I am having is an unstable Bluetooth connection.

Android phone (Nokia 8)

Connection remains stable for 15-20 seconds before dropping out

Always reconnects when asked, but very difficult to perform updates etc when so unstable

Same problem on both MPPT’s

Any ideas gratefully accepted.

MPPT SmartSolar
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misullivan avatar image misullivan commented ·

You should not do this... you cannot run two MPPTs on a single panel/string.. get another panel.. or go with a. Different solution... use the relay output on the MPPT to link the batteries (Assuming same voltage) or use an Orion-tr to charge the second battery from the first.

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1 Answer
Justin Cook avatar image
Justin Cook answered ·

@SteveMc, you're correct, the two MPPTs will constantly be fighting each other. There should be a single controller per array, without exception.

The photo seems to have failed to upload; please try to upload again?

In re to the connection issues, how far away from the controllers are you, and is your screen timing out? What version of Android are you running?

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