XTAR VX4 Universal Smart Battery Charger User Manual

1. Introduction

The XTAR VX4 is a versatile and intelligent battery charger designed to charge and test the capacity of a wide range of rechargeable batteries. It features intelligent charge recognition, manual current selection, real-time display of charging status, and advanced safety protections. This manual provides detailed instructions for safe and efficient use of your VX4 charger.

XTAR VX4 charger front view with display showing battery information — Figure 1: XTAR VX4 Universal Smart Battery Charger

2. Package Contents

Please check the package for the following items:

XTAR VX4 Charger
C-C Charging Cable
User Manual
PD20W Adapter (included in 'Set' variant)

Contents of the XTAR VX4 charger kit, including charger, cable, and manual — Figure 2: VX4 Kit Contents

3. Specifications

Feature	Specification
Model Number	VX4
Brand Name	XTAR
Output Power	≤37.5W
Output Current	2A
Power Source	Other (USB)
Output Interface	USB
Use	Standard Battery
Display Screen	Yes
Intelligent Charge	Yes
Quick Charge	Yes
Type	Electric, USB
Origin	Mainland China
Voltage	3.7V
High-concerned chemical	None
Data Transmission	No

Compatible Battery Types:

3.6V/3.7V Li-ion/IMR/INR/ICR (e.g., 10440, 14500, 14650, 16340, 17335, 17500, 17670, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22650, 25500, 26650, 32650)
3.2V LiFePO4
1.5V Li-ion (AAA/AA)
1.2V Ni-MH (AAA/AA/A/SC/C/D)

Diagram showing the wide compatibility of the XTAR VX4 charger with various battery types and sizes — Figure 3: Jaw-Dropping Compatibility

4. Safety Information

Fire Risk: Please mind potential fire risk and strictly follow the instruction manual for charging and storage.
Use only the provided or a compatible PD20W adapter for optimal performance and safety.
Do not disassemble, modify, or attempt to repair the charger.
Keep the charger away from water, moisture, and high temperatures.
Ensure proper battery polarity when inserting batteries into the charger.
Do not charge damaged or non-rechargeable batteries.
Unplug the charger from the power source when not in use.

Diagram illustrating the 8 leading protection technologies of the XTAR VX4 charger — Figure 4: Leading Protection Technology

The VX4 charger incorporates the following protection features:

Intelligent Detection
Timely Stop When Fully Charged
Over-Current Protection
Over-Charge Protection
Over-Voltage Protection
Short Circuit Protection
Reverse Polarity Protection
Soft Start

5. Setup

Connect the C-C Charging Cable to the Type-C input port on the VX4 charger.
Connect the other end of the C-C Charging Cable to a PD20W adapter or a compatible 5V-2A adapter/QC3.0 protocol adapter.
Plug the adapter into a power outlet. The charger's LCD screen will illuminate.

Video 1: XTAR VX4 Operation Video - Demonstrates connecting power and basic button functions.

6. Operation

6.1. Intelligent Charge Recognition

The VX4 charger automatically detects the battery type (Li-ion, LiFePO4, Ni-MH) and applies the optimal charging current. It stops charging when batteries are fully charged to prevent overcharging.

Diagram showing intelligent charge recognition, ensuring full charge, optimal current, and battery wake-up — Figure 5: Intelligent Charge Recognition

6.2. Charging Batteries

Insert Batteries: Place up to four compatible batteries into the charging slots, ensuring correct polarity. The charger will automatically detect the battery type and begin charging.
Select Charging Mode (if needed):
- Standard Charging Mode (CHG): For 3.6V/3.7V Li-ion, 1.5V Li-ion, and 1.2V Ni-MH batteries. This is the default mode.
- LiFePO4 Charging Mode (LiFePO4+CHG): For 3.2V LiFePO4 batteries. To switch to this mode, long press the C/V button.
Adjust Charging Current: While in a charging mode, single click the C/V button to cycle through available current levels (3A, 2A, 1A, 0.5A, 0.25A). Note: Charging current for 1.2V Ni-MH batteries is fixed at 0.5A. The selected current level indicates the upper limit for that slot.
Monitor Charging Status: The LCD screen displays real-time voltage, charging current, and battery charge level. Single click the MODE button to cycle through display content (e.g., mAh, mWh).

Animated diagram showing accurate battery recognition and mixed charging capabilities for different battery types — Figure 6: Accurate Battery Recognition and Mixed Charging

Animated diagram showing real-time display of charging status, including voltage and current — Figure 7: Real-Time Display of Charging Status

Diagram showing manual current level selection options for charging speed and Type-C input — Figure 8: Manual Current Level Selection

6.3. Capacity Measuring

The VX4 charger can also test the true capacity of batteries, including 1.5V Li-ion batteries.

Switch to Measuring Function: Long press the MODE button to switch from Charging Function (CHG) to Capacity Testing Function (Grad.).
Select Measuring Mode (if needed):
- Standard Capacity Measuring Mode (Grad.): For 3.6V/3.7V Li-ion, 1.5V Li-ion, and 1.2V Ni-MH batteries.
- LiFePO4 Capacity Measuring Mode (LiFePO4+Grad.): For 3.2V LiFePO4 batteries. To switch to this mode, long press the C/V button while in Capacity Testing Function.
Insert Batteries: Place batteries into the slots. The charger will begin the capacity measurement process, which typically involves a full charge, discharge, and then recharge cycle.
View Results: The LCD screen will display the measured capacity (mAh or mWh) after the process is complete. For 1.5V Li-ion batteries in the discharge phase, single click the mWh/mAh button to choose between displaying mAh or mWh.

Animated diagram showing how to switch between charging and capacity testing functions, and different capacity measuring modes — Figure 9: 1st Capacity Tester for 1.5V AA AAA Li-ion Batteries

6.4. Low-Voltage Battery Recovery

The VX4 charger features Micro-current Activation Technology to recover deeply discharged or 'dead' batteries, improving their recovery rate and safety.

Animated diagram showing the low-voltage battery recovery process using micro-current activation technology — Figure 10: Low-Voltage Battery Recovery

6.5. Backlight Control

To turn off the LCD backlight, long press the mWh/mAh button. Long press again to turn it back on.

7. Maintenance

Clean the charger regularly with a soft, dry cloth. Do not use abrasive cleaners or solvents.
Keep the charging slots free from dust and debris to ensure proper contact with batteries.
Store the charger in a cool, dry place when not in use.

8. Troubleshooting

Charger not powering on: Ensure the power cable is securely connected to both the charger and the power adapter, and the adapter is plugged into a working outlet.
Battery not charging: Check if the battery is inserted with correct polarity. Ensure the battery is compatible with the charger and is not severely damaged. Try cleaning the battery contacts and charger slots.
Error message on display: Refer to the specific error code in the full user manual (if available) or contact customer support.
Can I charge different battery types simultaneously? Yes, the XTAR VX4 supports mixed charging of various battery models (e.g., LiFePO4 and Ni-MH cells) in different slots, as it features accurate battery recognition.

9. User Tips

For best user experience, it is recommended to use an XTAR PD20W adapter. For emergency use, a 5V-2A adapter or one with QC3.0 protocols can be used.
Take advantage of the capacity testing feature to regularly check the health and true capacity of your rechargeable batteries.
When charging multiple batteries, consider setting a lower current level for a gentler charge, which can prolong battery lifespan.

10. Warranty and Support

For warranty claims, technical support, or further assistance, please contact the XTAR customer service or the seller from whom you purchased the product. Keep your proof of purchase for warranty purposes.

XTAR VX4