Li-ion 18650 cylindrical battery charger Xtar X4

Key Features

• supports protected 20700 and 21700 cells
• charging of Li-ion batteries controlled by a three-stage TC/CC/CV charging process
• charging of Ni-MH batteries using CC method
• four independent charging channels
• power bank function - USB output 5V/1A (only for Li-ion cells sized from 18650)
• three charging currents - 2x 2A / 4x 1A / 4x 0.5A (for Ni-MH and Li-ion cells up to 65mm in length)
• LCD display showing charging capacity, cell voltage, and charging current
• powered by any 2A USB charger and directly from the 230V mains
• compact size - easy to carry
• function to reactivate deeply discharged cells
• protections: short circuit, thermal, reverse polarity

Xtar is a renowned manufacturer of high-quality chargers for Li-ion batteries, flashlights, and Li-ion batteries. Xtar products are sold in over 120 countries, including the USA, Germany, Japan, and Russia. For the production of Xtar chargers, only the highest quality materials are used - from the casing material to efficient electronics. All Xtar chargers have CE certification required in European markets.

X4 is a professional processor-controlled charger with a three-stage TC/CC/CV charging process and an LCD display. It charges 1-4 Li-ion cells 3.6 / 3.7V and Ni-MH of any capacity in sizes AAA/R03, AA/R6, R14/C, 14500, 14650, 16340, 17500, 17670, 18350, 18500, 18650, 18700, 20700, 21700, 22650, 25500, 26650.

The backlit VA LCD display of the Xtar X4 continuously shows information about the charger’s operating status: battery charge expressed in mAh, battery voltage, and charging current.

What is the TC/CC/CV charging method? It is a three-stage charging process for Li-ion cells that ensures the cell remains in good condition by charging with the appropriate current at each stage and completing the charging process at the right moment.
The individual stages of the TC/CC/CV process are:

• TC Phase: cells discharged below 2.9V are 'woken up' with a lower current.
• CC Phase: after reaching 2.9V, the cell is charged with a constant current of:
  2Ax1/1Ax2/0.5Ax4 - powered by micro USB
  2Ax2/1Ax4 - powered by 230V
• CV Phase: when the cell is almost fully charged, the charger switches to charging with a decreasing current until the voltage of 4.2V is reached on the cell. After reaching 4.2V, the charging process is complete - the battery is fully charged.

Batteries left in the charger will undergo a natural self-discharge process. Charging will resume when the voltage on the battery drops below 3.9V.

The Xtar X4 charger has a function to reactivate deeply discharged cells and cells with a voltage of 0V. Many chargers on the market are unable to charge such batteries. Here, the Xtar X4 charger comes to the rescue, which in many cases allows for the 'rescue' of such cells. Simply insert the deeply discharged battery into the X4 charger, just like with normal charging - the charger will detect the discharged cell and attempt to reactivate it.

Note! Cells discharged below a certain level may suffer irreversible damage, and their reactivation may be impossible. It is important to avoid overly deep discharging of Li-ion batteries - this can lead to a significant reduction in their lifespan and capacity or render them completely inoperable.

The Xtar X4 also has an additional power bank function with a USB output of 5V and a maximum power of 1A. A Li-ion battery sized from 18650 with a minimum capacity of 2200mAh can be used as a power source. To use the power bank function, disconnect the charger from the power supply and insert a battery into it.

WARNING! The USB output is electronically protected against overcurrent and automatically turns off when the power draw exceeds 1A.

Included with the Xtar X4 charger is a 230V 2-pin power cable (commonly known as an 'octopus'). The power adapter is not included in the set. To power the charger, any USB charger, such as one from a phone, or a computer with a free USB port will suffice. The recommended charger power is 2.1A (2100mA).