question

vanhowling avatar image
vanhowling asked

Can someone double check to make sure I have this setup correct for my LiFePO4?

I'm new to electrical / solar / Victron, so I apologize in advanced if this has been asked before for this scenario.

1x 200Ah LifeBlue LiFePO4screenshot-2024-04-22-124643.png

Victron MPPT 100/50img-7066.png

Victron BMV 712 img-7067.png

The main reason I'm asking is because I'm experiencing this... screenshot-2024-04-22-124440.png

The SOC (which I understand is a calculated guess) is resetting to 100% while the internal battery monitor for the battery is saying less, in this example it was saying around 90%.

** In the pictures I have updated the Float Voltage down to 13.6 from 13.8 (which is what it was at while I was experiencing this). As well as Charged Voltage from 13.2 to the 13.4 pictured. BUT it did a 100% SOC jump right after I applied a charge, so I don't believe the fixed it?**


battery chargingBMV Battery MonitorMPPT SmartSolar
screenshot-2024-04-22-124643.png (295.4 KiB)
img-7066.png (256.1 KiB)
img-7067.png (249.0 KiB)
screenshot-2024-04-22-124440.png (32.8 KiB)
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matt1309 avatar image matt1309 commented ·

Try adjusting the peukert Exponent a little lower maybe 1.03.

It also might just need a full cycle to calibrate.

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pwfarnell avatar image
pwfarnell answered ·

The shunt syncs to 100% if the tail current is less than 4% = 8Amps in your case and is above the charged voltage. If the charging current is relatively small especially from solar then you can have a charging voltage that just creeps above your setting of 13.4V with a current below 8Amps so the shunt thinks the batteries are full. This question comes up many times and the solution is simple, set the charged voltage on the shunt to 0.2V below absorption, i.e. 14.2V in your case. This means that the batteries have to be really full to be at this voltage before the shunt resets to 100%.

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