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XTAR ST2 Charger Review

Discussion in 'Accessory Reviews' started by Frenkyou, Aug 15, 2019.

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  1. Frenkyou

    Frenkyou Super Member ECF Veteran

    Apr 26, 2019
    The XTAR ST2 charger, was sent to me directly from XTAR for review.

    XTAR ST2 4.1A Fast Battery Charger For Vape Mods

    Its sales package is a white cardboard box with a plexiglass hook to hang it from exhibitors.
    On the front side we can see the xtar st2, below the image the wording: '' battery charger with a fast and intelligent charging system '' in various languages.


    In the back part always in various languages ??the technical characteristics are reported, qr code for facebook and wechat, warranty code, scratch and check and ROHS and C E. certificates


    On the side profiles we find the compatibility data with Li-on / IMR / INR / ICR 18650-18700-20700-21700-22650-26650.
    and the salient features.



    The XTAR ST2 unfortunately came to me in a normal sales package, without the USB Type -C power supply with a two-pole European connection, apparently it can be purchased separately, so high-speed tests are postponed until I buy the adapter specific.

    The sales package contains:
    - XTAR ST2 battery charger
    - Qc3.0 compatible USB-A to USB-C cable
    - USB-C to USB-C cable for fast charging
    - Manual


    Main features of XTAR ST2:

    - Smart fast charging charger.
    - Max 2x4.1A, the fastest charger ever
    - Protection test of internal battery resistance
    - Battery temperature test with overheat protection
    - 1A / 2A / 4.1A optional current for each slot
    - OV activation restores the over-discharged batteries
    - Built with fireproof material to extend the life of the loader and ensure safety.
    - LCD information screen
    - Type C port, double rapid recharge protocol
    - Delicate design, excellent touch sensation
    - Manual and automatic, flexible control
    - Simple operation, clear display
    - Small and portable, stay in one hand
    - Input: PD2.0 (15V-3A), QC3.0 (5V-3A / 9V-2A)
    - Current: PD2.0: 4.2V-4Ax2 / 2Ax2 / 1Ax2 - QC3.0: 4.2V-4Ax1 / 2Ax2 / 1Ax2
    - Apply at 3.6 V / 3.7 V Li-ion / IMR / INR / ICR
    - Supported batteries: 18650/20700/21700/22650/26650.


    The XTAR ST2 charger is the latest product released by XTAR. The key features of the ST2 are fast charging up to 4.1A x2 and intelligent temperature control of the batteries being recharged. With the XTAR ST2 we can charge a 18650 2000 mAh battery in just 30 minutes.
    Battery temperature monitoring in real time, prevents overheating of the battery, safeguarding its duration and performance.
    The well-defined LCD display shows all the information on the battery charge status.


    The designe with the light blue stripes on the sides is very pleasant as is the feel to the touch. The XTAR ST2 is built in fireproof and resistant ABS + PC material.


    Its measurements are fairly small but not minute.


    In the upper part we find beyond the two refill slides, equipped with a contact for reading the battery temperature, a very defined display with white lettering on a blue background, the two status LEDs and two buttons (CH1 and CH2) that distinguish the two recharge slots available with the XTAR ST2.

  2. Frenkyou

    Frenkyou Super Member ECF Veteran

    Apr 26, 2019
    The XTAR ST2 charger has a USB Type-C input to connect our ST2 to the power supply (not included) or to another compatible USB socket (Power bank etc.). The specially designed Type-C input is available to support the PD2.0 and QC 3.0 protocols, compatible with various adapters.
    The air-flow helps to dispose of the heat produced during operation.


    In the lower part there are 5 soft rubber feet that raise the charger giving stability and allowing, through other openings, to dispose of some of the heat produced.
    Reported in white we find the data of the charger and the serial.


    With the XTAR ST2 charger we have the ability to charge 3.6V / 3.7V IMR / INR / ICR Li-ion batteries of the 18650/20700/21700/22650/26650 format and up to 4.2V with 4A, 2A or 1A for slots.

    It is also possible to charge 21700 Li-ion batteries protected up to 76mm.

    - To activate the "Upload" function:
    Connect the device to the power supply and insert the batteries.

    Three-phase charging makes the batteries healthier.
    The specially designed TC-CC-CV charging method safely and efficiently charges the batteries. The charger uses holding current (TC) to "wake up" and protects the batteries when the battery voltage is very low. After the voltage has returned to normal, the charger starts charging at constant current (DC) and the charging speed is guaranteed with a larger current. When the battery is almost fully charged, the charger starts charging at constant voltage (CV), to make sure the battery is fully charged and less damaged.

    Once powered, the XTAR ST2 checks the display (very clearly legible).



    Charging will start automatically. Press the CH1 or CH2 button to adjust the charging current.
    The notification LED above the display changes from green to red to indicate the charge status. On the LCD display we can read the information regarding the voltage of the batteries, the percentage of charge, the charge current, the internal resistance and the temperature of the batteries.

    The XTAR ST2 battery charger intelligently selects the most suitable current by reading the internal battery resistance. It is however possible to change it and switch to the three currents (1A / 2A / 4.1A) according to different needs.



    The charging temperature is monitored through the built-in sensors throughout the recharging cycle. In my tests I never exceeded 50 ° C; in that case I loaded a Samsung 30Q with 4.1A until the complete recharge of 4.20V.
    The built-in high-precision MCU makes the cut-off voltage up to ± 0.05 V and the XTAR ST2 charger at the end of charging (at 4.20V), automatically interrupts it and the notification LED turns green.


    The battery charger is equipped with a "Dual Protection" protection system to guarantee safe charging and maximize battery life. The "Dual Protection" system consists specifically of protection against internal resistance and thermal protection.
    1. Protection against internal resistance: the charger immediately detects the internal resistance of the battery. If the internal resistance is too high to allow recharging with 4.1 A, the device will automatically switch to a current of 2 A. Users can still change the charging current to 4.1 A by pressing the button (CH1 or CH2) . However, this change could damage the battery life.
    2. Thermal protection: the charger monitors the battery temperature throughout the charge. If the battery temperature is too high, the device will automatically reduce the charging current to protect the battery.
    Note: when the temperature is above 60 ° C, the charger automatically stops charging; when the temperature decreases, users must remove and re-insert the battery to continue charging.

    With the integrated intelligent detection system, when the polarity of the battery is reversed or the charging channel is short-circuited, the charger does not start charging, so as to ensure the safety of batteries, chargers and users.

    - Turn on / off the backlit screen:
    The display goes dark one minute after the end of use. Press and hold the CH1 or CH2 button for 1.5 seconds to dim the screen and reactivate each function.

    - To activate the "0V Activation" function:
    Insert the completely discharged batteries; recharging will begin after 10 minutes.

    - Legend of the color of the LED indicators:
    Green: standby / charge complete / contact defective / polarity reversed
    Red: charging / activation in progress
    No light: power supply disconnected


    The XTAR ST2 charger. It is a complete product and certainly fast in recharging up to 4.1A using compatible power supplies (which I don't have). Excellent materials and the possibility to load even the long 21700 protected. Important is the monitoring of the battery temperature, the OV activation to restore the over-discharged batteries and the possibility to manually choose 3 charging speeds. Really an excellent product recommended for purchase.

    We hope (as someone pointed out to me) that at least the selling price is almost halved, given that the part of the supply that affects enough the final sale price is missing, the QC 3.0 or PD 2.0 adapter costs enough, unless the smartphone one is reused.

    I thank Xtar for providing me with the product for the review XTAR,the best choice for fast charing
  3. Frenkyou

    Frenkyou Super Member ECF Veteran

    Apr 26, 2019

    The high-speed PD45-II adapter (which supports protocols QC3.0 and PD2.0) for the electrical wall socket has arrived and was kindly offered by Xtar to complete this review.

    It should be remembered that using a 5 V 3A QC adapter, we will be able to recharge both batteries at a maximum speed of 2A, always with this adapter at 4.1A it will only be possible to recharge a single battery.

    A PD2.0 charger is required to recharge both 4.1 A batteries.

    The PD45-II package is sober and elegant:


    B (2).jpg


    On this side of the loader the main technical characteristics are indicated and the various logos and marks are also reported in addition to the manufacturer's address.


    Note the QC 3.0 socket also present on the charger, powered by the special cable supplied (present in the standard package)


    The XTAR brand on display.


    On the display it is now possible to read the incredible speed of 4.1A and the relative working temperatures of our batteries, an XTAR 21700 INR and a Sony VT5A 18650


    This time two XTAR 21700 INR batteries are recharged to 4.1A!


    Specifically, this is a very powerful XTAR INR 21700 45A 4200Mah battery, following the relevant table and the technical data indicated by the manufacturer.

    lettera i.png


    Final Considerations:

    Every day we personally charge the batteries at around 1A or 0.5A, as this we consider a good balance between the charging time and the battery life. However, if things are desperate and we have no time, a quick top-up could be convenient, it will still be possible through the selection keys, reducing the amperage to 0.5A, 1A or 2A even during recharging.

    As much as I try, I can't find fault with the XTAR ST2, especially now that I've tested it at the amazing 4.1A speed, maybe the only exception is that an expensive (about 25 euros) separate adapter.
    Otherwise you can always fall back on a cheaper QC 5V 3A adapter and settle for 1x4.1A.

    The charger is offered with different options with and without QC network adapter:
    Xtar ST2 charger without mains adapter
    Xtar ST2 charger with QC3.O-UE network adapter (2x2A-1x4.1A)
    Xtar ST2 charger with PD45II-UE network adapter (2x4.1A)
    PD45II-UE network adapter (2x4.1A)

    I would like to thank XTAR again for providing me with the ST2 charger, the PD45-II network adapter and 2 fantastic INR 21700 45A from 4200Mah.
    If you want you can buy these products at the following link: US $25.99 35% OFF|XTAR ST2 Fast LCD Charger 30min Fully Charged Type C USB Charging Apply 3.6v/3.7v 22650 26650 20700 21700 18650 Battery Charger-in Chargers from Consumer Electronics on | Alibaba Group
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