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CTEK Assist helps you with everyday questions for your 12v/24v or EV Chargers and includes product information, a product selector tool, troubleshooting, user manuals, compatible accessories and much more.
It draws on CTEK’s knowledge and documentation to point you in the right direction—fast.
CTEK Assist for Lithium US
My charger won’t start charging and only the green power light is flashing. Is it faulty?
Not necessarily. A flashing green power light means the charger is in standby (Power Safe Mode) because it cannot detect the battery or the UVP is activated (lithium batteries). This is usually caused by one of the following:
Poor connection
The charger has not established—or has lost—the connection to the battery.
Check all clamps, eyelets, and contact points.
Deeply discharged battery
If the battery voltage is below about 2 V, the charger cannot recognize it and charging will not start.
CTEK chargers require a small amount of counter-voltage from the battery to begin or continue charging.
If the light keeps flashing after checking the connections, the battery is likely too discharged, not that the charger is faulty.
Or the battery on board UVP (under voltage protection) is activated.