XTAR VX4 or L4? Choosing a Charger and 1.5V Li-ion Batteries

XTAR VX4 or L4? Choosing a Charger and 1.5V Li-ion Batteries

Do you regularly replace batteries in remote controls, game controllers, wireless mice, flashlights or other household devices? If so, you may have wondered whether it makes more sense to keep buying disposable alkaline batteries or switch to rechargeables.

There is one important distinction. Most conventional rechargeable AA and AAA batteries use NiMH chemistry with a nominal voltage of 1.2V. Modern XTAR 1.5V rechargeable Li-ion batteries include built-in electronics that regulate their output voltage.

XTAR also offers two useful chargers: the XTAR L4 for straightforward AA and AAA charging, and the XTAR VX4 Visible Mixer for users who also want to charge other battery formats and assess battery capacity.

This guide uses practical examples to explain which charger suits different needs, which batteries each model supports, and why a higher mAh rating does not automatically make one battery the better choice.

2. XTAR L4 – straightforward everyday charging

The XTAR L4 is designed primarily for users who need to charge standard AA and AAA batteries.

Its main advantage is the ability to use one charger for both 1.5V rechargeable Li-ion and 1.2V NiMH AA/AAA cells. The charger automatically identifies supported batteries and adjusts the charging method.

• Four independent channels: charge one, two, three or four cells.
• AA and AAA sizes: supports the most common household battery formats.
• USB-C power: uses a 5V input, with 5V / 2A recommended.
• Charging current: up to 0.5A per channel, according to XTAR.
• Automatic identification: distinguishes compatible 1.5V Li-ion and NiMH cells.
• LED indicators: monitor each charging slot without needing a complex LCD.

How do you use the XTAR L4?

1. Connect the supplied USB-C cable to a suitable 5V USB power adapter.
2. Insert compatible AA or AAA rechargeable batteries, observing polarity.
3. The charger identifies the supported battery type and starts charging.
4. A steady red LED indicates normal charging; steady green indicates completion.
5. A rapidly flashing red LED may indicate an incorrect, damaged or unsupported battery. Do not attempt to force charging.

XTAR states an approximate charging time of 2.9 hours for four of its 4150mWh AA Li-ion cells under specified test conditions. Actual times depend on battery type, power supply and state of charge.

Who should choose it? Users who want a simple AA/AAA charger without advanced diagnostic features.

4. The key difference: what does capacity testing tell you?

Normal charging tells you that a battery has accepted a charge. It does not necessarily tell you how much usable energy the battery can deliver afterward.

The XTAR VX4 provides a GRADE mode that performs a controlled charge, discharge and recharge cycle. The result can help you compare batteries and identify cells with significantly reduced usable capacity.

A practical example

Imagine owning four identical rechargeable batteries for a flashlight. One appears to run out considerably faster than the others.

Instead of guessing, you can use GRADE with supported batteries. If three cells deliver similar energy under comparable test conditions while the fourth performs substantially worse, there is a good reason to investigate further or replace it.

This is not a laboratory analysis of every battery characteristic. Results depend on discharge current, temperature, age, protection electronics and the chosen testing procedure.

Why is mWh useful for 1.5V Li-ion batteries?

mAh describes electrical charge, while mWh describes energy. When comparing batteries of different nominal voltages, the energy rating in mWh is often more informative.

In this simplified example, both batteries have similar nominal energy despite different mAh ratings. Actual delivered energy depends on discharge conditions and battery electronics; this is not a measured comparison of two commercial products.

XTAR's regulated 1.5V Li-ion batteries also have voltage-conversion losses. This is one reason measured output energy is informative, although results from different chargers and test methods may not be directly comparable.

6. Which XTAR 1.5V Li-ion batteries should you choose?

EA Elektronika offers several models with different sizes, capacities and discharge characteristics. Always start with the physical size required by your device, then check current requirements and electrical compatibility.

For devices used infrequently, also consider kit cost, self-discharge, consumption by the internal regulation circuit and low-battery indication. Li-ion is not automatically the best option for every remote control or clock.

8. What about cost and long-term savings?

Rechargeable batteries require a higher initial investment but can be reused. The actual economics depend on battery and charger prices, the number of usable charging cycles, electricity consumption and how often disposable batteries would otherwise need replacing.

XTAR specifies hundreds or more than a thousand cycles for certain battery models. Such figures are based on defined test conditions and are not a guarantee that every cell will achieve the stated number of cycles in every application.

If you replace batteries every week, switching to rechargeables may recover the initial cost much sooner than in a device where alkaline cells already last for years.

10. Frequently asked questions

Can the XTAR L4 charge NiMH and 1.5V Li-ion batteries together?

Yes. The charger supports mixed charging of compatible AA/AAA chemistries in independent slots. This does not mean different chemistries should be mixed within the same electronic device.

Can I charge an 18650 battery with XTAR L4?

No. The L4 is designed for compatible 1.5V Li-ion and 1.2V NiMH AA/AAA cells. Choose the VX4 or another suitable charger for supported 18650 batteries.

Does XTAR VX4 automatically recognize LiFePO4?

Use the dedicated mode for 3.2V LiFePO4 and follow the operating instructions. Automatic detection should never replace checking battery chemistry and the selected charging mode.

Why won't my old charger charge a 1.5V Li-ion AA battery?

Regulated 1.5V Li-ion batteries contain electronics and require charging methods different from conventional NiMH or 3.7V Li-ion cells. Use a charger with explicit support.

Does a higher mAh rating always mean longer runtime?

Not necessarily. Voltage, actual energy in mWh, discharge current, temperature and device characteristics also matter. Figures from different battery chemistries are not always directly comparable.

Do 1.5V Li-ion batteries always provide accurate battery-level readings?

No. Regulated voltage can make conventional low-battery detection less predictable. Models designed for improved low-battery indication, such as CLR 4300, may help, but results depend on the device.

Can the VX4 test the capacity of every 1.5V Li-ion battery?

Do not assume universal compatibility. GRADE support depends on the charger version and the battery model and electronics. Check XTAR's latest compatibility information and the documentation for the exact VX4 supplied.