The four-bay charger with dual power input
The Xtar X4 is a battery charger with four independent bays, built for daily charging of Li-ion cells and NiMH or NiCd batteries. Unlike the brand's standard VC4, powered only over USB, the X4 plugs directly into the mains thanks to its included cable.
Mains or micro-USB, a rare flexibility
The X4 keeps a micro-USB input for portable use with a phone adapter or a power bank, on top of its direct mains cable. Charging adapts automatically to the number of cells inserted: two occupied bays climb to 2A each, four bays drop to 1A, or even 0.5A depending on the detected internal resistance.
A backup power bank output, with one condition to know
Another standout difference from the rest of the Xtar lineup: the X4 includes a USB 5V output that turns a charged cell, inserted in the fourth bay, into a backup source to rescue a phone, a flashlight, or a GPS on the go.
Three-stage charging, no manual adjustment
Three-stage charging (gentle pulse, then constant current, then constant voltage) protects cells, and a 0V activation function can revive cells discharged too deeply for other chargers to recognize. Unlike the MiBoxer C4 or the Xtar VC8, current isn't manually adjustable: it depends solely on the number of occupied bays.
X4 against the VC4, VC4SL, and PB2SL V2
With five Xtar chargers in the lineup, the choice isn't always obvious. The VC4 is the simplest, most affordable four-bay model; the VC4SL is its analytical version, with internal resistance measurement; the PB2SL V2 is a compact two-bay format built primarily as a power bank.
| Criterion | Xtar X4 | Xtar VC4 | Xtar VC4SL | Xtar PB2SL V2 |
|---|---|---|---|---|
| Power input | Mains or micro-USB | USB only | USB-C QC3.0 | USB-C QC/PD |
| Max charging current | 2A x2 / 1A x4 | Not stated | 3A (1 cell) | 2A per bay |
| Screen / measurements | Voltage, current, capacity | Voltage, current, capacity | + internal resistance | Simple screen |
| USB output (power bank) | 5V/1A, unplugged from mains | None | None | USB-C + USB-A up to 22.5W |
| Price found | ≈ £26.90 | ≈ £34.20 | ≈ £29.41 | ≈ £19.96 |
The X4 is the only one in the lineup to combine four bays, direct mains input, and a backup USB output, and in this market it's also the cheapest of the three four-bay-or-more options. The VC4SL wins for anyone wanting to measure internal resistance, and the PB2SL V2 makes more sense if the power bank function matters more than bay count.
