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Customer support


Welcome to CTEK and thank you for being a valued customer.

We are here to help and in this section you will find FAQs, troubleshooting, warranty information and video tutorials. If you can’t find what you are looking for, please contact us. For fastest response please write to us in English.

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Top 10 FAQ

  • Charger functions, MXS 5.0 TEST&CHARGE: I have a CTEK charger. It used to work well, but now nothing happens when I press the mode button. I can't change between the "MC", "CAR” and "SNOWFLAKE” modes. What can I do?
    See answer

    If you can't change the charging mode by pressing the mode button regardless of which battery you are trying to charge, the charger is probably faulty. If you still have the warranty, I recommend you go to your dealer with the charger, the receipt and a completed warranty claim form.

  • Batteries: AGM
    See answer

    AGM stands for Absorbed Glass Mat and differs from a standard Flooded battery in that the electrolite is held on a glass mat and pressed against the active plate area, instead of being allowed to flood around the plates. This type of battery has a low internal resistance and can accept charge very quickly making it ideal for the modern start stop systems. If the battery casing should become damaged the electrolite will not leak out.

  • Charger settings: AGM / * Snowflake
    See answer

    Because the AGM battery has a low internal resistance it can accept a higher charge voltage, in this mode the Bulk charge rate is 14.7v which is the optimum chare rate for the AGM type battery. In cold weather the internal battery chemistry slows considerably, this leads to the battery being reluctant to accept charge at a normal rate. By raising the charge rate to 14.7 (15v on the Polar) the battery accepts charge more readily

  • CONNECT CIG PLUG: Can I use your CONNECT CIG PLUG to charge the battery through the cigarette socket in my car?
    See answer

    Yes, but you should check that you have voltage to the socket even if the vehicle is switched off. If, for example, you can charge a mobile phone or get a GPS to work when the car ignition is switched off, you can also charge the car battery this way.

  • CTX BATTERY SENSE: Battery Sense Software update
    See answer

    12th July Issues have been reported with the latest update on our Battery sense app – our developers are currently working hard to rectify the issue. In the mean time we have taken the decision to roll back to the previous version of the app, We have been assured this will happen over the next few days - iOS first then Android to follow.

  • Charger functions: Bulk
    See answer

    A stage of intelligent charging where the battery is taken to approx 80% of full charge. This is achieved with constant current and a rising voltage. The cut off voltage can vary dependant on the type of battery being charged e.g. Flooded battery has a bulk charge voltage of 14.4v whereas the AGM has a cut off voltage of 14.7v. Note possible temperature compensation that makes the voltage vary depending on ambient temperature.

  • General: Can I leave the charger connected to the battery for a long time?
    See answer

    Yes! CTEK chargers are developed to fully charge a battery and then automatically switch over to long term maintenance.
    Before leaving the charger unattended for long time, ensure that the battery is fully charged, indicated by a green light.

  • Charger functions: Absorption
    See answer

    The control of gassing within the battery is very important when charging. At the end of the Bulk stage the battery is beginning to gas freely, if we were to continue with constant current and voltage the battery would gas excessively. In Absorption the voltage is now constant and the current is reduced to take the battery from 80% to 100% with minimal gassing, the CTEK charger is constantly responding to the amount of current the battery is taking and reducing accordingly.

  • Charger settings: BOOST
    See answer

    This mode is used on the much larger professional units and is designed to eliminate acid stratification on larger batteries or battery banks. The voltage is increased anything up to 15.8V in 12V mode or 31.6V in 24V mode, and a timer is user selectable between 8 hrs and 24hrs.

  • MXS 5.0 CHECK, XS 0.8, MXS 5.0, MXS 5.0 POLAR, MXS 10EC, MXS 10, MXS 5.0 TEST&CHARGE: is lit
    See answer

    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 charger is not connected to a 12V battery.
    Test: Test with a fresh 12V battery.

    Explanation 4: The charge cycle is interrupted in step 1.
    Test: Test to restart the charge cycle, if it still fails in step 1 the battery is sulphated and needs to be replaced.

    Explanation 5: The charge cycle is interrupted in step 4.
    Test: Test to restart the charge cycle, if it still fails in step 4 the battery is can’t be charged and needs to be replaced.