question

vast avatar image

Inaccurate reading battery voltage

I have a voltage discrepancy in my sistem.

For example, now I read these voltage:

- multimeter = 47.6V

- SmartBMV-712 = 47.04V

- SmartSolar MPPT 250/100 = 47.10V

- VE. Bus Summary for Quattro 48/8000 (on Venus GX) = 46.83V

(My battery is 48 module from Nissan Leaf, connected 6S8P. This is the reason for so low voltage.)


Between battery and BMV shunt I have 1m, and than 0,5m of 90 mm2 cable. Between BMV shunt and solar charge controler I have 1m of 35 mm2 cable.


I read some answers about inaccurate voltage readings, and I connected a cable in my Quattro on Voltage sense. Also, I change the fuse on BMV from 100mA to 2A, but no results.


If the voltage difference between BMV and MPPT is reasonable, the difference between Quattro and BMV is over 0.2V, and the difference from multimeter is huge.

Before Quattro and MPPT 250/100 I own a inverter charger from Taiwan (PIP 4048MS) and a solar charge Midnite 150 Classic with no voltage reading problem at all.

MPPT ControllersMultiPlus Quattro Inverter ChargerBMV Battery Monitorvoltage
1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.


For example, now I read these voltage:

- multimeter = 47.6V where are you connecting the meter to (I presume the battery)

- SmartBMV-712 = 47.04V. I presume off the victron connect app

- SmartSolar MPPT 250/100 = 47.10V I presume off the victron connect app

- VE. Bus Summary for Quattro 48/8000 (on Venus GX) = 46.83V


Please check with the volt meter the readings below and adivse


1. the Battery Voltage

2. the Voltage at the SmartSolar Bat + - terminals (two readings) (say at midday and at Night)

3. the Voltage at the Quattros battery terminals ON the Quattro


4 please supply some photos of the installation as well



0 Answers