Erratic Output from SmartSolar MPPT 100/50

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dave556 asked Jun 4, '19

Erratic Output from SmartSolar MPPT 100/50

This system is in an RV (caravan). Victron Energy equipment includes SmartSolar MPPT 100/50, MPPT Control, BMV-712, VictronConnect App. Batteries at 100% SOC, 1.81A load, 600W solar array. It seems the controller has difficulty providing only the 1.8 amps drawn by the load steady state when the batteries are floated and not drawing any current. In this case, the solar controller stops supplying current, the battery drives the load, and then the solar controller pulses a bunch of current back into the battery to replace the charge used. Then stops, letting the battery continue to drive the load. This happens every few seconds. Charge current is steady when batteries are less than 100%. Here is a link to a video showing this MPPT 100/50 behavior

MPPT Controllers battery charging charger error

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Answer 1 · 2019-07-01T05:25:05Z

Guy Stewart (Victron Community Manager) answered · Jul 01, 2019 at 05:25 AM

Hi Dave,

This looks normal to me.

Batteries are full and you have a very small load.

The charge controller is trying to maintain the battery voltage, not power the load.

So it will push a little bit, and then back off if the battery voltage rises above the target.

It's fine for the batteries to transact a few amps like this at the top of their charge cycle.

The MPPT and BMV will also report different currents. The BMV is much more accurate at current counting than the MPPT, so you should trust it's current readings before the MPPT.

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

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