question

patr avatar image
patr asked

Why did Skylla drive voltage higher than the setting?

On a recent night I was woken up by an alarm on my CCGX saying the voltage was over my alarm setting of 14.8v.

My two Skylla IP44s are set for:

Charge algorithm: 7 (for my 1200Ah of Relion LiFePO batteries)

Absorption voltage: 14.2

Float voltage: 13.5

My system also has two MultiPlus 3000 inverters (master / slave) but they were not connected to shore power. I also have 1500 watts of solar panels. But this was at night. The Skyllas were plugged in to shore power. I cut off shore power and the alarm cleared.

Looking at the VRM history, I can see that one of the Skylla's (Sky2)was outputting significant current, spiking at the time and the output voltage going up to 15.03. The other Skylla did not appear to be outputting any current and had an output voltage of 14.83. Both Skyllas had been in Absorption mode and went to Off when shore power was cut.

screen-shot-2022-03-25-at-43541-pm.png


This has not happened since, but I have not been using shore power much.

Any ideas why this happened?

thanks

Pat

Skyllaovervoltage
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1 Answer
wkirby avatar image
wkirby answered ·

My thought is that Sky2 is having a problem with temperature compensation. It might be somehow measuring a lower temperature than the actual battery temperature and so the compensated charge Voltage would be higher than Sky1.

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patr avatar image patr commented ·

Why would that make it go 0.63v over the set limit?

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Related Resources

Skylla-IP65 product page (12v, 24v)

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Skylla-TG Charger product page (24v, 48v)

Skylla-TG GMDSS product page (24v)


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Additional resources still need to be added for this topic