Miscellaneous Issues; Unable To Operate As A Dc-Dc Charger Or Power Supply; Interrupted Firmware Update; Ground Current - Victron energy MPPT 150/70 Manual

8.10. Miscellaneous issues

This chapter describes issues that were not covered in the previous troubleshooting chapter.

8.10.1. Unable to operate as a DC-DC charger or power supply

Avoid using the solar charger as a DC-DC charger (e.g., to charge a 12V battery from a 24V battery bank). Connecting a battery
to the PV terminals under certain operational conditions can damage the solar charger, which is not covered by the warranty.
Instead, use a dedicated DC-DC charger or converter. Check our
Also, refrain from using the solar charger as a power supply without batteries connected. Although this operation won't harm the
solar charger, it might not support all types of loads. Some loads may function, while others may not, particularly at low load
power, where the solar charger's response might be too slow to maintain a constant voltage. Please note that support is not
provided for such situations.

8.10.2. Interrupted firmware update

An interrupted firmware update is recoverable and there is no need to worry. Simply attempt to update the firmware once more.

8.10.3. Ground current

If a ground current is detected in the system during normal operation, take the following steps:
• First, thoroughly inspect all the equipment connected to the system and check for any ground faults.
• Next, verify the number of connections to ground in the system. Ideally, there should be only one point in the system connected
to the ground, which should be at the battery.
• For more information on system grounding, see the "System grounding" chapter in the
Note that the solar charger is non-isolated and the minus of the PV input is at the same potential as the minus of the battery
output.

8.10.4. Programmable relay issues

To troubleshoot if the relay is not functioning correctly, follow these steps:
• Use the VictronConnect app to verify the relay functionality setting. Refer to the
• Check for continuity between the C and NC terminals when the relay is not energised.
• Check for continuity between the C and NO terminals when the relay is energised.
• Keep in mind that connecting a circuit with excessive current or voltage to the relay can cause damage. For the relay's current
and voltage rating, refer to the
covered by the warranty.

8.10.5. PV Short relay reset procedure

This procedure outlines the reset process for the internal protection mechanism, known as the PV Short Relay, in the Smart Solar
Charger 250/100.
The protection consists of a latching relay, which is mounted across the PV Input. When the firmware detects a short between the
PV inputs and the battery outputs, by monitoring the battery voltage for an over-voltage, it engages the relay and, as such, shorts
the PV Input. See errors 80 to 83 in the
List of models with newer PV short protection with latching relay:
• SmartSolar VE.Can MPPT 250/100 - The PV Short Relay was introduced from serial number HQ2150 and newer.
When to perform this procedure?
Applying a higher battery voltage than configured in the solar charger (eg. 48V battery to a 12, 24 or 36V configured charger), and
then connecting the PV array, can cause the protection to "mis-trigger". Meaning that the charger sees an over-voltage, and as
such assumes that there is an internal fault and then engages the latching protection.
Recovering from such mis-triggers is the purpose of the here documented reset feature.
Page 62
MPPT solar charger manual
Technical specifications [68] chapter. Any damage resulting from exceeding the rating is not
Relay configuration (not energised).
Error 80 to 88 - PV Input shutdown [66]
DC-DC converter product page for a complete product range.
Wiring Unlimited
Programmable relay settings [26]
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Troubleshooting