XTAR ST2 4.1A Battery Charger

XTAR’s ST2 a new fast charger from XTAR. Furthermore a mere 30 mins to charge 2×18650’s. A new style, and battery deck. However does the XTAR ST2 perform ?

This product has been sent with the kind generosity of XTAR for the purpose of an impartial review. Furthermore the thoughts that you find below are mine and are not influenced by the fact that this was gifted.

Please note that this article may contain affiliate links which help to fund the makenvape.uk website.

Lets Begin

Box Contents

The XTAR ST2 comes supplied in the typical XTAR white packaging, with a usable battery list on one side, and basic features on the other. Additionally on the back are some more product information, warranty number, social media links, scratch and check authenticity. While in the box itself is the XTAR ST2, USB cable, and instruction guide.

Important – The ST2 is a 3.6/3.7 V charger only, this will not charge AA type batteries unlike the VC4S.

XTAR ST2 Package Contents
1 x XTAR ST2 Charger
1 x USB-A to USB-C charging cable
1 x USB-C to USB-C charging cable
1 x Manual

Build Quality

Construction of the XTAR ST2 is with flame retardant and fire resistant ABS and PC. Importantly giving the charger structural strength and yet peace of mind in its use. However the ST2 is a little bulkier than previous twin battery chargers, from XTAR. Furthermore the soft rubber finish on the exterior, gives the charger a soft, yet incredibly sturdy feel.


As simple as the XTAR ST2 looks there is plenty of action going on underneath the surface. Importantly the ST2 will automatically start charging at the best amperage be reading the internal resistance of the battery itself. Additionally the ST2 will automatically drop the charging current if you are using a less than idea charger. XTAR refers to this as over-current protection. Furthermore the XTAR ST2 also contains over-voltage, over-charge and short circuit protection. Importantly this protects your charger and stops the potential risk of fire.

Unquestionably the feature of reviving over discharged batteries even from 0 V, is always going to be a god send. Especially when you may have accidentally taken your batteries a bit too low.

Importantly the XTAR ST2 utilises the same three stage charging that many have come to love about XTAR.


Firstly when looking at the XTAR ST2 you notice that the LCD is angled. Thus making it easier to read from a seated position. Indeed this makes viewing the state of the charge much easier, and perfect for me. Without a doubt the angled screen saves me having to get up, and lean over to check if the battery or batteries are charged yet.

While charging, the ST2’s screen details all the information you may require for charging you batteries, ready for your next vape. Moreover the amperage being used to charge the battery is displayed, battery temperature, current voltage of the battery, and finally the percentage of charge completed.

Battery Bays

Secondly you are most likely to spot the curved oval tabs on the battery bays. These smart little slivers of presumably metal, are thermistors or at least a form of measuring the battery exterior temperature. Importantly helping to ensure that the battery is not being over charged with too high a current, if the XTAR ST2 detects this it will automatically drop the amperage being pushed to the battery.

The individual battery bays are themselves are nice and wide, so you can charge two 26650’s without any problem of them getting into each others way. Furthermore they face the opposite way for a XTAR charger, so instead of the negative being at the top it is now at the bottom. In addition when inserting and removing batteries it now feels much easier, then on other models.

Control Buttons

On the XTAR ST2 there is a button for each retrospective bay, i.e. CH1 and CH2, allowing you to increase or decrease the amperage of the charge. Fundamentally there is 1A, 2A, and 4.1A charging if your plug adapter is capable of pushing the higher current.

You can if you so desire turn off the backlight to the LCD by holding down either of the function buttons. A point of note I don’t recommend sleeping while you charge your batteries, or leaving them unattended for long periods of time. Safety First People.

Plug Adapter Requirements

Charge plug adapters that are required to push the higher current required by the XTAR ST2 are Quick Charge 3.0 (QC3.0) or Power Delivery 2.0 (PD2.0) chargers. More specifically a PD2.0 15 V 3A charger or a charger that supports QC3.0 5 V 3A / QC3.0 9 V 2A.

It should be noted I have only tested the XTAR ST with a QC3.0 5 V 3A as that is the only charger I have at this stage to test the ST with. While using a QC 5 V 3A plug adapter, you can only charge both batteries at a maximum of 2A or a single battery at 4.1A.

You will require a PD2.0 charger to achieve 2 x 4.1 A charging.

On a daily basis I personally charge my batteries at around 1A or 0.5A, as it is a good balance between charging time and the life span of the batteries. However if things are desperate and you have not got the time then a fast charge shouldn’t affect them too badly.

List of compatible batteries for charging:

3.6/3.7V Charging of Li-ion/IMR/INR/ICR1.2V Charging of Ni-MH/Ni-CD


Despite lacking a discharge feature the XTAR ST2 is a solid and well rounded performer. In addition I am especially pleased to be able to reduce the amperage down to 1A or 2A rather than being locked in to the maximum current of 4.1A.

I particularly love the new size of the battery bays, and hope this will be implemented on all of XTAR’s future releases, especially on future variants of VP4C, and the VC4S chargers. Additionally wether down to less tension in the springs or simply the effect of pushing rather than pulling. Without a doubt the ease of inserting and removing batteries on the XTAR ST2 is great and again would love to see in future releases.

If you are after a small fast charger for your vaping batteries then the ST2 has got you covered despite being a bit bigger than the VC2 its not a gigantic difference. Moreover the ST2 is 33 mm high x 75 mm wide x 149 mm long and weighing 156 grams. Making it still portable enough for taking out and about with you.


As try as I might I just can’t find fault with XTAR ST2. However the only one exception is that an expensive separate charger is required in order to utilise the 2 x 4A charging. Perhaps it is time to make an all in one type system, with internal wall adapter built in.



Build Quality


Build Design





  • Strong Durable Feel
  • Tilted LCD
  • Larger Battery Bays
  • Greater Accuracy in Battery Temp
  • Adjustable Current


  • Expensive Additional Charger Required for 2 x 4A

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