question

victronvalhowell6283 avatar image
victronvalhowell6283 asked

Batteries going into float too son

I have 4 Lifeline 4D AGM batteries. The Victron suite consists of :

Cerbo GX with GX 50 Display

Multiplus 12/3000

4x Victron MPPT controllers

Multi Controller for Multiplus

BMV 712

MPPTs and BMV are connected to the Cerbo via VE Direct cables (some through USB)

Multi is connected to Cerbo through VE Bus connection.

When battery state is approx 80% SOC, all four MPPTs are in bulk. When shore power is added, system quickly goes to float, when it should be in bulk. Sustain is NOT on. No additional VS or Assistants are running . Please see attached photos for more details.

Suggestions?

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battery charging
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1 Answer
pwfarnell avatar image
pwfarnell answered ·

1. It would be useful if you can post a plot of the battery current and voltage from VRM when this happens if you have more frequent data logging than the default 15 minute, or a Victron Connect screenshot from the BMV712. Then we can see what happens at the change to float.

2. Are you sure that your BMV712 is indicating the correct SOC because if the BMV is not accurate then the batteries may actually be full. Have you set the BMV as the system battery monitor in Settings>System setup. Post a screenshot of your BMV settings, are the MPPT also set to 14.3V absorption.

3. Is this a new problem on a system that has run OK for some time or is it a new system with the problem from new.

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kevgermany avatar image kevgermany ♦♦ commented ·

@victronvalhowell6283

Some more questions

What are the MPPT battery/charge settings?

Is DVCC on?

Is this configured for DESS?

Battery float voltage seems low, Is this the manufacturer recommendation?

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