question

kevgermany avatar image
kevgermany asked

VRM, Strange DC power values.

System EasySolar II GX 5K,

Orion 48/12

Cerbo + GX Touch 50.

4xPylontech US5000

Lynx Power in

Lynx Distributor

System is in inverter mode, relying on solar.

The only DC load is the Cerbo

The only AC load is a fridge/freezer.Draws 70-90W AC.

DC power fluctuates a lot with really high values at times.

I know the DC values are calculated and only indicative, but are values showing over 100W entering the battery realistic and to be expected?1000013922.jpg

VRM
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3 Answers
Alexandra avatar image
Alexandra answered ·

@kevgermany

Since it is volt amps, you might find the DC bus is higher in voltage than the battery and it is messing things around a bit.

Since the DC bus and the battery voltage are not always the same then a guestimates DC based on bus voltage might be the reason? (not measured)

I have found not having the Has DC system on if there is no shunt for it better. Since now the system expects a load and is trying to make its consumption up? Also theories since I don't know the inner workings.... A Cerbo load is not high enough to make an appreciable reading and is not worth having the feature on for. Since we are talking mA of power not A.

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JohnC avatar image
JohnC answered ·

@kevgermany

The underlying issue here is that all the data values aren't sampled at exactly the same time. So the 'by difference' calculation can vary widely if something is changing frequently.

There's a widget in VRM I use to monitor the auto switching in of an Orion 48/12. With only per-minute recording it misses a lot of the variations, but some can be quite spectacular..

1700480568862.png

I get a general feel for the Orion working, but that 1900W spike is likely my waterjug (for a cuppa coffee). Only a single data point, but VRM just happened to catch it.

Just mismatched sampling times. And normal behavior..


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kevgermany avatar image
kevgermany answered ·

Thanks both

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