Xtar X4 Charger
(10 reviews)
The Xtar X4 charges 4 Li-ion or NiMH cells at once, runs on mains or USB power, and turns into an emergency power bank thanks to its 5V USB output.
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Characteristics
- Bays: 4 independent (2A max per 2)
- Power: Mains or micro-USB (2 inputs)
- Output: USB 5V/1A, power bank function
- Compatibility: Li-ion 10440-26650 + NiMH/NiCd
- 4 bays, mains power and USB power bank output
Detailed overview: Xtar X4 4-bay charger with power bank output
The Xtar X4 is a battery charger with four independent bays, built for everyday charging of Li-ion cells (10440 to 26650, including 18650, 20700 and 21700) and NiMH or NiCd batteries (AAAA, AAA, AA, A, SC, C). Unlike the brand's basic VC4, which only powers on over USB, the X4 plugs straight into the mains with its supplied cable, while keeping a micro-USB input for use on the go with a phone adapter or a power bank.
Charging current adapts automatically to the number of cells inserted: two occupied bays climb to 2A each (two 18650 2500mAh cells fully charged in about ninety minutes), four bays drop to 1A, or even 0.5A depending on the internal resistance detected. Three-stage charging (gentle trickle, constant current, then constant voltage) protects the cells, and a 0V activation function can revive deeply discharged cells that other chargers refuse to recognise.
The LCD screen shows, for each bay independently of the other three, the voltage, charging current and the percentage of capacity already charged, a genuine plus for tracking the health of your cells. Another key difference from the rest of the Xtar range in our catalogue: the X4 has a 5V USB output that turns a charged cell, inserted in the fourth bay, into a backup power source for a phone, a torch or a GPS unit on the move (the charger must be unplugged from the mains for this output to work).
Fitted with the usual protections (overcharge, overvoltage, short-circuit, reverse polarity) and CE, FCC and RoHS certifications, the Xtar X4 suits anyone who wants a complete four-bay charger, equally at home on a desk or tucked into a travel bag. One caveat: protected 20700/21700 cells are not supported by this model.
Full specifications
Detailed characteristics
Charging capacity
| Number of slots?Number of batteries that can be charged at the same time. | 4 |
|---|---|
| Compatible formats?Accepted battery formats (AA, AAA, 18650, 21700...). | AAAA, AAA, AA, C, 14500, 14650, 16340, 17350, 17500, 17670, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22650, 25500, 26650 |
| Compatible chemistries?Recognised battery chemistries (Li-ion, LiFePO4, NiMH, NiCd...). | Li-ion, NiMH, NiCd |
| Max charging current?Maximum charging current per slot, in milliamps. | 2000 mA |
| Adjustable charging current?The user can manually pick the charging current. | No |
| Independent charging per slot?Each slot manages its own charge, independent of the other cells (different formats and chemistries can be mixed). | Yes |
Power input
| Power source?Built-in mains plug, USB port (Micro-USB or USB-C) or 12 V car socket. | Mains (built-in cable), Micro-USB |
|---|
Output and features
| USB output (device charging)?The charger can also act as a power bank: it uses the inserted cells to charge another device. | Yes |
|---|---|
| Output ports?Connector type used for the power-bank output. | USB-A |
Display and diagnostics
| Display?Type of visual feedback on charging status. | Detailed LCD screen |
|---|---|
| Automatic chemistry detection?The charger automatically adapts its charging profile to the inserted cell, with no manual setting. | Yes |
| Test / repair functions?Advanced functions beyond plain charging: real capacity measurement, internal resistance, reconditioning of worn cells, discharge cycles. | Reconditioning / revival |
Size
| Weight?Weight of the empty charger, in grams. | 235 g |
|---|---|
| Dimensions (L × W × H)?Length × width × height, in millimetres. | 140 × 118 × 38 mm |
Warranty
| Warranty?Length of the manufacturer's warranty. | 1 year |
|---|
User manual / Instructions for use
Comparison
With five Xtar chargers in our catalogue, the choice is not always obvious: here is how the X4 stacks up against its three closest siblings, matching searches like "Xtar X4 vs VC4" or "Xtar X4 vs VC4SL". The VC4 is the simplest and most affordable 4-bay model in the range; the VC4SL is its analysing version, with internal resistance measurement; and the PB2SL V2 is a compact 2-bay format built first and foremost as a power bank.
| Criterion | Xtar X4 | Xtar VC4 | Xtar VC4SL | Xtar PB2SL V2 |
|---|---|---|---|---|
| Bays | 4 independent | 4 independent | 4 independent | 2 (18650/21700) |
| Power | Mains or micro-USB | USB only | USB-C QC3.0 | USB-C QC/PD |
| Max charging current | 2A x2 / 1A x4 | Not stated by Xtar | 3A (1 cell) | 2A per bay |
| Screen / readings | Voltage, current, capacity | Voltage, current, capacity | + internal resistance | Simple screen (charge state) |
| USB output (power bank) | 5V/1A, with a cell in bay 4 | None | None | USB-C + USB-A up to 22.5 W |
| Observed price | ≈ £27 | ≈ £34 | ≈ £29 | ≈ £20 |
In short, the Xtar X4 is the only model in the range to combine four bays, a direct mains input and a backup USB output: a solid compromise for anyone who wants a complete charger without investing in the VC4SL's analysis features. The VC4 remains the most affordable choice for simple USB use, the VC4SL wins for anyone who wants to measure the internal resistance of their cells, and the PB2SL V2 is the better pick if the power bank function matters more than the number of bays.
Related video
Video: XTAR X4 Battery Charger Review - My Everyday Charger! - Published on 19/08/2019
Our tester's review: Christophe Delpuech
The X4 has become our everyday desk charger since we unboxed it. Unlike the brand's basic VC4, this one plugs straight into the mains with its supplied cable, no need to hunt for a beefy USB adapter. The four cells charge fast: with two 18650s at once, it climbs to 2A and the charge is done in about ninety minutes. With all four bays loaded, the current automatically drops to 1A, charging takes longer but nothing overheats. The LCD screen is clear and finally gives useful numbers (voltage, current, charged capacity) instead of a single LED. The power bank function is handy in a pinch: unplug the mains cable, leave a charged cell in the fourth bay, and the USB port can bring a flat phone back to life. One honest downside: that output does not work while the charger is plugged into the mains, you have to unplug it first, which is not obvious the first time. For the price, it remains a solid, versatile charger, without the VC4SL's advanced analysis features.
Frequently asked questions: Xtar X4 4-bay charger with power bank output
It has four independent bays, compatible with Li-ion cells from 10440 to 26650 (18650, 20700, 21700...) and NiMH/NiCd batteries (AAA, AA...). The current adjusts automatically depending on how many cells are inserted.
Yes, but only when unplugged from the mains: with a charged cell in the fourth bay, its 5V USB output can bring a flat phone or torch back to life. It is not a regular power bank, more of a backup function.
The VC4 only charges over USB and has no power output. The X4 adds a direct mains input and a 5V USB output to power a device, at the cost of a slightly less detailed screen than the VC4SL.
With two bays occupied, the X4 delivers up to 2A per cell: two 18650 2500mAh cells fully charge in about ninety minutes. With all four bays in use, the current drops and charging takes longer.
No, Xtar states that protected 20700/21700 formats are not supported by this model. Check the length of your cells before buying if you use protected versions, which are longer than unprotected ones.
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Published on 01/09/2026