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bigbadbob76 asked

Charge current assistant problem.

I have a switch wired across the aux input of my multiplus and an assistant which sets the charge current to 0A when the switch is closed (<1v) and to 90A when the switch is open (>4v).

I also have "disable charger when charge current should be zero" ticked.

This puts the multiplus into pass-through so that the batteries only charge from solar even when grid is available.

However I have noticed that every ten minutes or so the inverter goes into bulk or absorption charging mode rather than pass-through for a second or so and alternates back and fore a few times before going back into pass-through. this then repeats after another ten minutes.

It doesn't seem to actually allow much charge current through but is annoying.

Can anyone explain this behaviour?

I have tried setting the assistant to 0A if aux input voltage <2v, but same problem.

The multiplus seems to be over-riding the assistant.

multiplus firmware is 487.

Assistants
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w8dev avatar image w8dev commented ·

I have the same setup with the assistant and a switch (relay on the cerbo) and I've never experienced this.


What do you have set as the charging current set in VE Config under the Charging tab? I have mine set to 0.

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bigbadbob76 avatar image bigbadbob76 w8dev commented ·

Thanks @w8dev

I'll check tonight but off the top of my head I think it's set at 90A.

I'll try 0A and if that doesn't solve it I'll try disabling the charger just to see if that changes anything.

I have tried linking the Aux input with a short wire and it still has the problem so it's not noisy switch wiring that's at fault.

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Mike Dorsett avatar image Mike Dorsett commented ·
try setting the minimum current to 0.1A and see if that stabilises the issue. Otherwise it sounds like a firmware bug.
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bigbadbob76 avatar image bigbadbob76 Mike Dorsett commented ·

Thanks Mike.

Will that not prevent it going into pass-thru? as charge current will never be zero.

I want it to go into pass-thru when the switch is closed and enable charge when switch is open.

It does seem like a firmware issue, might be time for an update.

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2 Answers
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bigbadbob76 answered ·

Update- Disabling DVCC stops the problem.

So I re-enabled it and disabled the global charge limit in DVCC, Problem came back.:-(

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w8dev avatar image w8dev commented ·
Sounds like a firmware issue then. I'm currently running 502 without issues.
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bigbadbob76 answered ·

This problem is still ongoing and my work colleague now has it too since he added a relay to control the charge current switching.

I'm running venus v2.66 on Rpi and a multiplus with fw 481

He is running Venus v2.92 on Rpi and a multiplus ii with fw 506.

Turning on DVCC but unticking all DVCC options doesn't stop it flip flopping between passthrough and charge.

Turning off DVCC stops it so I'm guessing DVCC is fighting with the charge current assistant.

Another colleague (also fw 481) has DVCC enabled and all options ticked but has charge disabled using the tick box on the charger tab of victron configure and he does not have the problem.

This may be a Rpi issue as it doesn't happen with W8dev's cerbo, so I can't expect victron support.


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Related Resources

VEConfigure Assistants manual