Incongruity Between Multi and SmartShunt Voltages

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gstonier asked Mar 6, '24

Incongruity Between Multi and SmartShunt Voltages

Apologies if this has been asked and answered. I have looked around the forum but could not fund this exact issue.

Multiplus 12/3000/120

SmartShunt

CerboGX

Batteries are Epoch 12v 300ah. Batteries have internal BS so not connected to CanBus

The Multi / SmartShunt / an MPPT / and an Orion are all connected to the Cerbo.

The problem is that when I program the Multi in VEConfig using the battery manufacturer bulk charge and float charge settings, (14.6/13.8) I consistently get a variance of .3v between what the SmartShunt reads (and the batteries) and what the multi thinks the batteries are at.

For example, with the Multi set at 14.6 for charge, the batteries want to bulk at 14.9. With Float set to 13.8, the batteries will Float at 14.1. To get the proper parameters for the battery manufacturers recommended settings, I need to set charge to 14.3 and Float to 13.5.

I can't figure out this incongruity. Any assistance/direction that can be provided is greatly appreciated.

SmartShunt battery system voltage

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Modifications Space

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Answer 1 · 2024-03-06T01:05:39Z

Al answered · Mar 06 at 01:05 AM

Do you have DVCC turned on and SVS? Otherwise you'll need to use the voltage sense connections on the multi to the battery.

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Answer 2 · 2024-03-06T02:01:36Z

gstonier answered · Mar 06 at 02:01 AM

Thanks for the comeback Al. I don't have DVCC turned on because the batteries aren't on the Victron list. So the voltage sense connections I guess will be the route. It's funny though it's always that .3 volt difference.

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Answer 3 · 2024-03-06T02:25:09Z

JohnC answered · Mar 06 at 02:25 AM

@gstonier

DVCC doesn't need batteries networked in. In your case the V from the shunt will be passed over to the Multi, and it will use that for it's own charge reference. You said the shunt V matches battery V, so all should then be sweet. Try it..

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