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joelimvp asked

Multiplus float voltage not stable causing battery in charging/discharging cycle

I have Multiplus 3000 and two battle born Lithium batteries in parallel. The trailer is plugged into my house’s 30amp. The float voltage is set to 13.5v. The Smart Shunt is connected to the batteries terminals and the Smart Dongle is plugged into the buses. When Multiplus is in float mode and DC load is running, I noticed sometimes the power was pulled from the batteries and sometimes the Multiplus charged the batteries. The voltage is bouncing up and down. I set the Multiplus to charger only, it’s the same. Is it normal the batteries got charged/discharged cycle in float mode and the voltage bounces? Should I disconnect the battery when plugged in to avoid cycling the battery?

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MultiPlus Quattro Inverter Chargerfloat
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joelimvp avatar image
joelimvp answered ·

I got a response from Lance from Victron. I was told that it's normal and after turning off both DC and AC load, both the voltage and current are very steady. So, false alarm! Here's the response from him

"Looks normal if you have any loads attached. You are reading the battery voltage reacting to draws and charging. The Multi will have a very stable voltage. Turn off all of your loads – AC and DC and see what happens."


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snoobler avatar image
snoobler answered ·

If you're in lithium mode, you're likely hitting the re-bulk limit.


Try the following setting:


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joelimvp avatar image joelimvp commented ·
The charging state stayed in float, didn’t restart from bulk though.
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snoobler avatar image snoobler joelimvp commented ·
Did you try the settings to see if the behavior changed?
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mbmike29 avatar image mbmike29 commented ·

I purchased my Multiplus-II 12/3000/120-50 120V from Battleborn and they programmed the float voltage as 13.6V for my (600AH of) Battleborn batteries. I'm seeing the same behavior. I assumed my voltage was fluctuating because in essence the Multiplus-II is acting as the converter for my RV.

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