Troubleshooting Guide

CTEK UC 800
CTEK US 800
CTEK MULTI US 25000


MUS 7002
MUS 3300
MUS 4.3
MURS 7.0
D250S DUAL
CTX Battery Sense

CTEK UC 800

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for CTEK UC 800 (90KB)
No LED is lit when the charger is connected only to the battery
Explanation: The plug has to be connected for the LED to be lit.No LED is lit when the charger is connected only to the power outlet
Explanation: The charger has to be connected to battery for the LED’s to light up.No LED is lit when the charger is connected to both the power outlet and the battery
Explanation: The battery voltage could be under 4V.
Test: Test against another battery that is fresh. If nothing happens, even though the voltage is above 4V, the
charger could be faulty.The charger does not switch from Battery Almost Full into maintenance charging Battery Full
Explanation 1:Larger loads are connected to the battery at the same time.
Test: Disconnect the loads from the battery and try to charge again.
Explanation 2: Defective battery
Test: If possible, measure the voltage on the battery when the charging is completed. If the voltage is under 7V
the battery is probably faulty.
Test: Try the charger on another fresh battery.Battery Almost Full and Battery Full is lit (flashing rapidly) simultaneously and there is a ticking sound
Explanation 1: Bad connection
Test: Move the clamps and make sure there is no loose connection in the quick connector, Comfort Connect.
Explanation 2: The charger is working in the desulphation phase
Test: Leave the charger to charge for 24h (with some supervision). If the charger does not start charging (one of
the LED’s are lit) within 24h the battery is in very poor condition.Battery Almost Full switches to Battery Full after the charge has been stopped
Explanation: When the charger restarts the battery voltage is monitored. If the battery voltage is above 6,5V the
charging will not commence. When the battery is between 6,5V and 7,2V it is considered as fully charged. The
charging will automatically start again when the battery voltage drops below 6,5V.

The error LED Battery Error is lit
Explanation: Reverse polarity
Test: Make sure that the + cable/clamp is connected to the + terminal and the – cable/clamp is connected to the –
terminal.

CTEK US 800

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No LED is lit when the charger is connected only to the battery
Explanation: The plug has to be connected for the LED to be lit.

No LED is lit when the charger is connected only to the power outlet

Explanation: The charger has to be connected to battery for the LED’s to light up.

No LED is lit when the charger is connected to both the power outlet and the battery
Explanation: The battery voltage could be under 6V.
Test: Test against another battery that is fresh. If nothing happens, even though the voltage is above 6V, the
charger could be faulty.

The charger does not switch from Battery Almost Full into maintenance charging Battery Full
Explanation 1: Larger loads are connected to the battery at the same time.
Test: Disconnect the loads from the battery and try to charge again.
Explanation 2: Defective battery
Test: If possible, measure the voltage on the battery when the charging should be finished. If the voltage is under
7V the battery is most likely faulty.
Test: Try the charger on another fresh battery.

Battery Almost Full and Battery Full is lit (flashing rapidly) simultaneously and there is a ticking sound
Explanation 1: Bad connection
Test: Move the clamps and make sure there is no loose connection in the quick connector, Comfort Connect.
Explanation 2: The charger is working in the desulphation phase
Test: Leave the charger to charge for 24h (with some supervision). If the charger does not start charging (one of
the LED’s are lit) within 24h the battery is in a very poor condition.

Battery Almost Full switches to Battery Full after the charge has been stopped
Explanation: When the charger restarts the battery voltage is monitored. If the battery voltage is above 12,9V the
charging will not commence. When the battery is between 12,9V and 14,4V it is considered as fully charged. The
charging will automatically start again when the battery voltage drops below 12,9V.

The error LED Battery Error is lit
Explanation: Reverse polarity
Test: Make sure that the + cable/clamp is connected to the + terminal and the – cable/clamp is connected to the –
terminal.

CTEK MULTI US 3300

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No LED is lit when the charger is connected only to the battery
Explanation: The charger requires voltage from the battery for the Standby LED to be lit.
Test: Connect the charger to a fresh battery. If the battery charger is still not lit, it may be faulty.

No LED is lit when the charger is connected only to the power outlet
Explanation: One of the LED’s at the lower row should light up when the charger is connected to the power
outlet.
Test: Make sure that there is power from the power outlet. If the charger is still not lit the charger may be faulty.

No LED is lit when the charger is connected to both the power outlet and the battery
Explanation: The battery voltage could be under 2.2V.
Test: Test against another battery that is fresh. If nothing happens, even thought the voltage is above 2.2V, could
the charger be faulty.

The charger does not switch from Battery Almost Full into maintenance charging Battery Full
Explanation 1: Larger loads are connected to the battery at the same time.
Test: Disconnect the loads from the battery and try to charge again.
Explanation 2: Defective battery
Test: If possible, measure the voltage on the battery when the charging should be completed. If the voltage is
under 14,1V the battery is most likely faulty.
Test: Try the charger on another fresh battery.

Battery Almost Full and Battery Full is lit (flashing rapidly) simultaneously
Explanation 1: Bad connection
Test: Move the clamps and make sure there is no loose connection in the quick connector, Comfort Connect.
Explanation 2: The charger is working in the desulphation phase
Test: Leave the charger to charge for 24h (with some supervision). If the charger does not start charging (one of
the LED’s are lit) within 24h the battery is in a very poor condition.

Battery Almost Full switches to Battery Full after the charge has been stopped
Explanation: When the charger restarts the battery voltage is monitored. If the voltage is above 12,9V the
charging will not commence. When the battery is between 12,9V and 14,4V it is seen as fully charged. The
charging will automatically start again when the battery voltage drops below 12,9V.

The charger goes into Standby mode after the power is cut and the charging does not start again
Explanation: The charger will turn into Standby if the voltage in the battery is below 6V when the power is back
on
Test: Start the charging again by pressing on the mode button.

The error LED Battery Error is lit
Explanation: Reverse polarity.
Test: Make sure that the + cable/clamp is connected to the + terminal and the – cable/clamp is connected to the –
terminal.

CTEK MULTI US 7002

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No LED is lit when the charger is connected only to the battery
Explanation: The plug has to be connected for the LED’s to be lit.

No LED is lit when the charger is connected only to the power outlet
Explanation: One of the LED’s at the lower row should light up when the charger is connected to the power
outlet.
Test: Make sure that there is power from the power outlet. If the charger is still not lit the charger can be faulty.

No LED’s are lit on the top row when the charger is connected to both the power outlet and the battery
The LED’s on the lowest row are lit and you can change charging mode. None of the LED’s the top row on is
indicating charging status. Explanation: The battery voltage could be under 1,5V.
Test: Try to charge the battery in Supply mode for approximately 5 min. Then try regular charging.
Test: Test the charger on a fresh battery. If nothing happens the charger may be faulty.

Battery Almost Empty is lit for 4 hours and then turns into error mode Battery Error
If the battery voltage is not above 12,5V after 4h the charger will turn into error mode, because the voltage has not
increased in the way it should have done. Explanation 1: The battery is too large in relation to the capacity of the
charger.
Test: Make sure that the battery/batteries size is not larger than the recommendations for Multi XS 7000 (150Ah).
Test: Try to restart the charger because the charger might need more time to charge the battery.
Explanation 2: Larger loads are connected to the battery
Test: Disconnect the battery and try to charge it without the loads.
Test: Try to restart the charger because the charger might need more time to charge the battery.
Explanation 3: If the battery is warm and/or is boiling heavily during the charging, it is most likely due to a
defective cell in the battery.
Test: Change the battery

Battery Almost Empty is flashing for 4 hours, then turns into error mode Battery Error
Explanation: The battery is probably too sulphated to revive. The battery is faulty and it is time to change it.

Battery Almost Full is lit and then turns into error mode Battery Error
The analysis phase is testing if the battery can retain the charger given. Explanation 1: Large loads are connected
to the battery and are draining the voltage
Test: Disconnect the battery and try charging again.
Explanation 2: The battery cannot retain the charge given.
Test: The battery needs replacing.

The error LED Battery Error is lit
Explanation 1: Reverse polarity
Test: Make sure that the + cable/clamp is connected to the + terminal and the – cable/clamp is connected to the –
terminal.
Explanation 2: The clamps are short circuited
Explanation 3: For chargers of the older type the error mode is flashing when only the plug is connected.

CTEK MULTI US 25000

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No LED is lit when the charger is connected only to the battery
Explanation: The plug has to be connected for the LED’s to be lit.

No LED is lit when the charger is connected only to the power outlet
Explanation: One of the LED’s at the lower row should light up when the charger is connected to the power
outlet.
Test: Make sure that there is power from the power outlet. If the LED is still not lit the charger may be faulty.

No LED’s are lit on the top row when the charger is connected to both the power outlet and the battery
The LED’s on the bottom row are lit and you can change charging mode. None of the LED’s the top row on is
indicating charging status. Explanation: The battery voltage could be under 1,5V.
Test: Try to charge the battery in Supply mode for approximately 5 min. Then try regular charging.
Test: Test the charger on a fresh battery. If nothing happens the charger may be faulty.

Battery Almost Empty is lit for 4 hours and then turns into error mode Battery Error
If the battery voltage is not above 12,5V after 4h the charger will turn into error mode, because the voltage has not
increased the way it should have done. Explanation 1: The battery is too large in relation to the chargers capacity.
Test: Make sure that the battery/batteries are not larger than the recommendations for XS 25000 / Multi XS 25000
(500Ah).
Test: Try to restart the charger because the charger might need more time to charge the battery.
Explanation 2: Larger loads are connected to the battery
Test: Disconnect the battery and try to charge it without the loads.
Test: Try to restart the charging, the charger might need more time to charge the battery.
Explanation 3: If the battery is warm and/or is boiling heavily during the charging, it is most likely a faulty cell in
the battery.
Test: Change the battery

Battery Almost Empty is flashing, then turns Battery Error
Explanation: The battery is probably too sulphated to revive. The battery is faulty and it is time to change it.

Battery Almost Full is lit and then turns into error mode Battery Error
The analysis phase is testing if the battery can retain the charge given. Explanation 1: Large loads are connected
to the battery and drain the voltage
Test: Disconnect the battery and try charging again.
Explanation 2: The battery cannot retain the charge given.
Test: The battery needs replacing.

The error LED Battery Error is lit
Explanation 1: Reverse polarity.
Test: Make sure that the + cable/clamp is connected to the + terminal and the – cable/clamp is connected to the –
terminal.
Explanation 2: Loads are connected to the battery which requires more power than the charger can provide.
Test: Turn off or disconnect the loads when charging.
Explanation 3: The clamps are short circuited in Supply mode
Test: Separate the clamps

Temperature LED Battery Error is lit

Explanation: DC interruption or short circuit in the cable.

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