Overvolt during Absorbsion phase AGM batteries

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rupez1 asked Jan 9, '22

Overvolt during Absorbsion phase AGM batteries

I keep getting a few over volt alarms during aborbsion. I’ve a multiplus and lynx system with cerbo GX. I’ve 330Ah of AGM lead acid batterie. I‘ve set the charge voltage limit in the DVCC menu at 14.8V and checked the multiplus settings and they are factory (14.4 absorption). The charge voltage goes up to 15V for short periods during absorption. It cycles around 14.6 - 15.0V.

Any idea why this might be? Will it be damaging my batteries?
Any tips on how to stop it happening?

I know the bank is smaller than that recommended for the 12/3000/230 but I’m saving up for Lithium…

Thanks in advance…

cerbo gx lynx shunt overvoltage

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Answer 1 · 2022-01-09T05:44:51Z

Matthias Lange - DE answered · Jan 09, 2022 at 05:44 AM

If you use the default settings then it can be the temperature compensation. Do you have connected the temperature sensor? What temperature do you have at the batteries?

With default settings the charging current is way too high for 330Ah of lead batteries. Recommend for most lead batteries is 0.1-015 of the capacity. So 33-50A for you batteries.

That high charging current can also cause a overshot of the voltage limit.

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rupez1 commented · Jan 09, 2022 at 08:35 AM

Matthias Thanks ver much. I have dialed back the current as you suggest. there is a temperature probe. The battery temperature was about 10C. Would that be a problem? How could I bring the voltage down? There is a limit on the DVCC and also within the multiplus menus. Which one is priority? Thanks again…

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