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

  • D250SE: Can I use D250SE for lithium batteries?
    See answer

    Yes it works both with lead-acid and lithium (12V LiFePO₄) batteries.

  • 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.

  • 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

  • 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.

  • D250SA: Can I use D250SA for lithium batteries?
    See answer

    No, it works only with lead acid batteries.

  • CT5 TIME TO GO, CT5 TIME TO GO GULF EDITION: If I choose Recond, how do I know when it's finished?
    See answer

    When the charger is in "Care" mode it also means that the reconditioning is complete. Reconditioning is activated by pressing the Mode button and selecting "Recond".

  • D250SE, D250SA: Do I need an external regulator for the solar panel?
    See answer


  • 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.

  • INDICATOR EYELET M8, INDICATOR PANEL 3.3M, INDICATOR EYELET M6, INDICATOR CLAMP, INDICATOR CIG PLUG, CTX INDICATOR PLUG 12V, CTX INDICATOR EYELET M8, INDICATOR PANEL 1.5M: I have a INDICATOR connected to the battery in my car. The red lamp flashes even after I've fully charged the battery. Should it do this? I thought the INDICATOR would be green when the battery is fully charged?
    See answer

    The CTEK INDICATOR is exactly what the name says – an indicator. It provides a snapshot of the system voltage level and works best when the battery has reached a rest level (this can take up to a few hours to reach after the battery was used). As soon as you open a car door or turn on the ignition, the battery voltage vill temporarly drop and the indicator shows yellow or even red. To make things easier, you can position the INDICATOR where you can see it without having to unlock or use any voltage in the car.

  • Charger settings: RECOND
    See answer

    A mode that is used for reviving deeply discharged batteries, breaking down sulphation and reversing acid stratification. It requires a manual selection from the user and will add an extra step to the charge cycle, It uses a voltage of 15.8v to deliberately gas the battery in a controlled way in order to re-mix the acid to get an optimized acid balance (acid weight). This mode is also recommended for Ca/Ca batteries which require the higher voltage when charging.