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ako asked

BVM-700 Jumping to 100%

This is driving me crazy , i cant seem to get my friends older style BMV-700 shunt to show the batteries charging , when discharging its fine and slowly showing a decrease on battery capacity but just after the input from the Solar panels start go from negative to positive current flow the shunt jumps from around 63% to 100% . In settings it theres a toggle to go to 100% on Reset , tried the toggle both on and off , makes no difference . . My own Shunts are Smart shunts and run direct to Cerbo , my friend doesnt have one so i had to connect a VE to USB cable from the back of the round display .

Would be very grateful if someone could explain what im missingwhatsapp-image-2024-07-14-at-181717.jpeg

BMV Battery Monitor
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nickdb avatar image
nickdb answered ·

What parameters have been used for it to synchronise?

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ako avatar image
ako answered ·

set-2.jpegThese but happy to change any of wrong

set-1.jpeg

Not sure about th toggle for Battery Starts Synchronised as my smart Shunts displays it differently , with them i have option to KEEP SOC so it rises and falls with current correctly .



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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

The "charged voltage" is to low.
Try to set it slightly below the absorption voltage of your chargers.

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ako avatar image ako commented ·

Thank you , which way should the toggle be set to KEEP SOC as its shown differently as BATTERY START SYNCONSED .

I cant understand why the charge voltage should be the problem because to change to 100% i understood it has to be a combination of Voltage , Tail Current 4 amps and Duration 5 mins .

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ ako commented ·

Small charging currents from PV can cause a false synchronization.

Tail current is % not A! With your setting it's 4% of 400Ah = 16A

https://www.victronenergy.com/media/pg/SmartShunt/en/all-features-and-settings.html#UUID-630b31ba-1591-6ae6-cf95-89313c0720f5

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ako avatar image ako Matthias Lange - DE ♦ commented ·

Going to change that now to 1% as there's 2x 200 amp/hr batteries and tail current is given in the handbook as 4 amps , thanks for that , silly mistake . What do i set BATTERY START Synchronised toggle to , on or off or doesn't it make any difference

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ako answered ·

Thank you but i read that when i set up my own smart shunts but this isnt a Smart shunt , its a BVM-700 , an older model which as you can se on the screen shots has not got the three options , if it said KEEP SOC then i would know as that what im looking to do but it doesn't .

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ commented ·

OK than read the manual of the BMV-700...

https://www.victronenergy.com/media/pg/BMV-700/en/all-features-and-settings.html#UUID-c15fc6a8-ed6b-e370-be65-999470a0ec7f

Default is "clear" that sets the SOC after power loss to unknown and you need to do a full charge to let the SOC sync to 100%.

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