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chris-adamache asked

Victron Smart Shunt Incorrectly Reading 100%

I have two 30A Victron Blue Smart Chargers working in parallel to charge a 280AH Lithium battery in my travel trailer. I'm monitoring the state of charge of the battery using the Victron Smart Shunt. I set the parameters in the Victron connect app for the Shunt & chargers to align with the reccomendations for lithium. I charged up my battery to 100% and then synchronized SOC on the app via bluetooth with the Smart Shunt. I then took my rig off grid and used my battery down to 88%. When I plugged my rig back in a day later, the reading on the smart shunt shot up to 100% right away even though it was pulling 30A from the chargers and I'm sure it wasn't 100% full. I was expecting it to trickle back up to 100%.

Any ideas why the SOC reading jumped right to 100% instead of slowly ticking up from 88% to 100%? I had the Charged Voltage set at 13.2V and have since changed it to 14.2V as per the recommendation from my Victron tech support guy. Any other thoughts?


SmartShunt
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Martijn Coster (Victron Energy Staff) avatar image Martijn Coster (Victron Energy Staff) ♦♦ commented ·

@Chris Adamache

see information in 10.3.11 of the manual. Try increasing the charged voltage to 13.8V
https://www.victronenergy.com/media/pg/SmartShunt/en/troubleshooting.html#UUID-ec008a3b-6c1c-f675-47d6-0605d5e18c

1652951900230.pnggr. Martijn

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Alexandra avatar image
Alexandra answered ·

@Chris Adamache

As a possible issue. Power was disrupted to the shunt (possibly on the positive cable). The shunt is set to starts synchronised.

Switch that setting off.

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chris-adamache avatar image chris-adamache commented ·
Thanks for that answer, Alexandra. However, I don't believe power was disrupted to the shunt. Can you be more specific as to what the benefit and implication of turning off the "starts synchronised" setting would be? Why would turning that setting off resolve this issue? :)
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kevgermany avatar image kevgermany ♦♦ chris-adamache commented ·
Shunt can either start at zero or 100%, it's also possible to set it manually. Shunt works by measuring current into and out of battery, then calculates state of charge based on all the readings since it last read 100%

Shunt synchronises when charged voltage is reached, charge current drops to the tail current value or less for the charge detection time.

From your description you have a couple of possibilities causing the problem. Shunt settings or faulty wiring/power disconnect or faulty unit.

If the settings are correct and the wiring isn't causing a power off situation, get the dealer to replace under warranty.


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chris-adamache avatar image chris-adamache kevgermany ♦♦ commented ·
Thanks @kevgermany. I'm sure the issue isn't faulty wiring/power disconnect. I think i need to adjust the tail current and charge detection time. Appreciate your reply. :)



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