Battery Cable Voltage Drop - Victron energy BlueSolar MPPT 75/10 Manual

• If the system includes a properly installed and configured battery monitor, you can monitor the current flowing in (or out) of the
battery, while the solar charger indicates the current generated by the solar array.
• Use a current clamp and compare the current flowing from the solar charger into the battery and the current flowing from the
battery into the DC system.
• A positive sign alongside the current reading indicates current flowing into the battery, whereas a negative sign suggests
current being drawn from the battery.

8.6.3. Battery cable voltage drop

If the battery cables experience a voltage drop, the solar charger will produce the correct voltage, but the batteries will receive a
lower voltage, potentially leading to undercharged batteries. An excessive voltage drop of more than 2.5% is unacceptable.
The voltage drop can result in the following:
• Longer battery charging times.
• Battery receiving a charge voltage that is too low.
• Loss of charge power.
• Increased heat in the battery cables.
The voltage drop can be caused by:
• Battery cables with insufficient cross-sectional area.
• Poorly crimped cable lugs or terminals.
• Loose terminal connections.
• Faulty or loose fuse(s).
For more information on cabling issues and voltage drop, refer to the
Battery cable voltage drop check
Make sure that the charger is charging with the full current, preferably in the morning. Use the VictronConnect
Step 1
app to confirm the output current.
Using the VictronConnect app or a multimeter, measure the voltage on the battery terminals of the solar
charger.
Step 2
Measure the battery voltage on the terminals of the battery using a multimeter.
Step 3
Step 4 Compare the two voltages to identify any voltage difference.
VE.Smart Networking can assist in mitigating a small cable voltage drop. However, for a substantial voltage drop, there may be
an issue with the wiring between the solar charger and the battery, which requires rectification before proceeding.
Page 49
MPPT solar charger manual
Wiring Unlimited Book.
Troubleshooting