VC4 is a professional processor charger with a three-stage TC / CC / CV charging process and an LCD display. Charges 1-4 3.6 / 3.7V Li-ion and Ni-MH cells of any capacity in the sizes AAA / R03, AA / R6, 10440, 14500, 14650, 16340, 17500, 17670, 18350, 18500, 18650, 18700. In two extreme channels it is possible to charge batteries in sizes R14, R20, 20700, 21700, 22650, 25500, 26650, 32650.

The backlit LCD display of the Xtar VC4 charger shows up-to-date information on the charger's operating status: battery voltage, charging current, charge used to charge the cells, indicates possible errors, and informs you when charging is complete. At the same time, the current operating status for two channels is displayed. Switching between the other two channels is possible using the CH button on the charger housing. Information about the load used can be used to measure the capacity of batteries. To measure the capacity of the battery, it must be discharged to the appropriate voltage cut-off level (usually 2.5V for Li-ion, 0.9V for Ni-MH) and inserted into the VC4 charger. When charging is complete, the display shows the charge used to charge the battery. It will always be 3-5% higher than the actual battery capacity. It results from the fact that the process of charging batteries is never 100% efficient, i.e. a slightly larger charge is needed to charge the battery than it results from the actual capacity of the cell.

The maximum charging current is 1A and is available only for the two extreme channels and only when the middle channels are not used. The batteries in the middle channels are always charged with 0.5A. When charging 3 or 4 batteries, VC4 charges all batteries with 0.5A.

What is the TC / CC / CV charging method? It is a three-stage process of charging Li-ion cells that ensures that the cell is in good condition by charging with the right current at each stage and ending the charging process at the right time.
The individual stages of the TC / CC / CV process are:
• TC phase: cells discharged below 2.9V are "woken up" by a lower current.
• CC phase: after reaching 2.9V, the cell is charged with 0.5A DC.
• CV phase: when the cell is almost charged, the charger switches to charging with decreasing current until it reaches 4.2V on the cell. After reaching 4.2V, the charging process is completed - the battery is fully charged.

Batteries with a voltage of 4.1V or higher are considered charged by the charger. To fully charge such a battery, insert it into the charger before turning it on. Charged batteries left in the charger will undergo a natural self-discharge process. Charging will resume when the battery voltage drops below 4.1V.

The Xtar VC4 charger has the function of reactivating deeply discharged and 0V cells. Many chargers on the market are not able to charge such batteries. Here, the Xtar VC4 charger comes in handy , which in many cases allows you to 'save' such cells. Just insert a deeply discharged battery into the VC4 charger, as with normal charging - the charger will detect a discharged cell and attempt to reactivate it.

Warning! Cells discharged below a certain level are irreversibly damaged and may not be reactivated. Avoid too deep discharge of Li-ion batteries - this can lead to a significant reduction in their durability and capacity or lead to their total malfunction.

Charged batteries left in the charger will undergo a natural self-discharge process. Charging Li-ion batteries will resume when the battery voltage drops below 3.9V. For Ni-MH batteries, charging does not resume when the voltage drops due to self-discharge.

Complete with the Xtar VC4 charger, we get a USB cable and a protective cover for the charger during transport. The set does not include a power supply. To power the charger, any charger with a USB cable is sufficient, e.g. from a telephone, or a USB socket or a computer with a free USB port. Recommended USB power supply is 2.1A (2100mA). It is possible to use a weaker power supply, VC4 will adapt the charging current to the capacity of the power source.