speedcat avatar image
speedcat asked

Victron Controller - super high yields?

I've had my boat on shore power all winter. Just moved it up to the lake, now it's at anchor and relying on solar power, which appears to be working well.

The issue I'm wondering about - when I first disconnected from shore power, for the first 2 days the history in my VictronConnect app showed very large solar panel yields, like the first day was 1.16kWh (giant for two 110W solar panels?!) and the second day was 560Wh, also very large for one day. This is in April, in Seattle, so we really don't get that much sun anyways.

On the first day, it appears that most of the yield was from Bulk mode and the rest in Absorption mode, with nothing in Float mode. On the second day, there was some Float mode.

After this, the yields have slowed down to a more normal reading between say 120 and 240Wh per day, with floating occuring for some part of every day.

I'm wondering a couple of things. First what could explain the above huge yields.

Two, is it normal for the Victron controller to report only that yield that battery bank can accept? In other words, I expect more yield on some days but it appears low because it appears that the controller is only reporting the yield that the battery can accept. When the battery is full, almost no yield is showing.

Finally, is there a way to track the total solar yield regardless of the battery status? In other words, I want to know the total photovoltaic watt hours that were available, even if the system didn't use those.

Hope this makes sense, and thank you for your help with these questions.
MPPT ControllersVictronConnectvictron
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1 Answer
kevgermany avatar image
kevgermany answered ·
The first two days yields are within the output of the panels. You have potentially 220W/h per hour and with the longer days, this could easily be 2KW/h per day.

So the assumption is that on shore power your batteries were not being fully charged and the solar spent 2 days bringing them back to fully charged.

Solar controllers can only report the power that is output. If there's no load, output is zero and zero is reported. The batteries and loads control the output. The controller maximeses panel yield and offers what's available to and loads/batteries. It's not possible to work out the difference between available power and output power.

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