BMV 712 not reseting SOC to 100% even after MPPT 15/75 has reached fully 100% SOC

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raymiller asked Nov 20, '18

BMV 712 not reseting SOC to 100% even after MPPT 15/75 has reached fully 100% SOC

I've had this issue for a while and seems to be that the MPPT 15/75 is not spending enough time at the Absorbtion State even though I've trying to set it for a longer period. The overnight discharge is about 16%. As you can see by the graph it is reset on the second Absorbtion state for the solar day on November 14.

On day 14th November the BMV 712 resets the SOC to 100% on the second Absorbtion state but does not on all other occasions the battery voltage reaches 28.4V.

My system is 24V and a 140AH Lithium-ion Phosphate battery. I've set up the BMV712 as per the manual

So it would seem to me the MPPT 15/75 Absortion state time is not matched with the BMV 712.

Some guidance in the various manuals for how to successfully achieve a better co-operation between the two devices would be appreciated.

screen-shot-2018-11-16-at-83759-am.png(105.0 kB)

MPPT Controllers BMV Battery Monitor

screen-shot-2018-11-16-at-83759-am.png (102.6 KiB)

mppt1575.png (87.3 KiB)

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Michael Connolly commented · Dec 19, 2018 at 10:08 AM

How did you get these graphs? Thanks

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wkirby ♦♦ Michael Connolly commented · Dec 19, 2018 at 10:18 AM

Those graphs are screenshots, most likely from his VRM site.

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Michael Connolly wkirby ♦♦ commented · Dec 19, 2018 at 10:36 PM

Thanks WKirby. Now the next dumb question. What’s a VMR site??

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JohnC ♦ Michael Connolly commented · Dec 20, 2018 at 02:39 AM

The Victron portal. Magic stuff. https://www.victronenergy.com/live/vrm_portal:getting_started

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Modifications Space

Node Red Space

Answer 1 · 2018-11-20T17:39:57Z

raymiller answered · Nov 20, 2018 at 05:39 PM

A further graph showing the longer time in Absorption State on 14th November when the BVM 712 reset the SOC to 100%. The time was possibly longer due to the lower solar availability with the MPPT dropping back to the Bulk charge state then achieving the second Absorption state, holding the voltage longer to trigger the required for BVM 712 SOC reset.

mpptnov14.png (82.2 KiB)

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raymiller commented · Nov 20, 2018 at 05:43 PM

The first Absorption state is usually about 3 minutes with the second Absorption state was 12 minutes.

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Answer 2 · 2018-11-21T20:27:01Z

raymiller answered · Nov 21, 2018 at 08:27 PM

Found the other posts under:

Blue Solar MPPT leaves absorption too early

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