XTAR VX4 Visible Mixer 1.5V/3.6V/3.7V Li-Ion 3.2V LiFePO4 1.2V Ni-MH battery charger and capacity tester
Quick take
The XTAR VX4 is a multi-battery charger and capacity tester that’s designed for rechargeable chemistries including 1.5V Li-ion (AA-size), 3.6V/3.7V Li-ion, 3.2V LiFePO4, and 1.2V Ni-MH. It stands out for people who want to verify what older or mixed cells can actually deliver, not just charge them. The main caveat is that it does not support alkaline or other non-listed rechargeable types, so it is not a universal charger for every battery in your drawer.
Pros and cons
Pros
- Supports multiple rechargeable types, including 1.5V Li-ion AA, 3.6V/3.7V Li-ion, 3.2V LiFePO4, and 1.2V Ni-MH.
- Capacity testing focus, with an LCD and an energy readout (mWh) that helps you sort usable cells.
- Charging behavior includes battery-type separation and an algorithm that detects the battery mode.
- Includes built-in safety protections and uses multi-stage charging for Li-ion batteries.
Cons
- Not for alkaline or other chemistries outside its supported list.
- It is physically larger than some users expect, so it may not feel “travel compact.”
- Capacity readouts do not always match the advertised mWh labels on batteries, which can be disappointing if you expect brand-spec perfection.
What buyers think
Buyer-review evidence is broadly consistent on the following themes: the VX4 charges correctly across the supported rechargeable types, and the capacity testing is genuinely useful when you have older cells or mixed batteries that you cannot confidently trust. Users also describe the display and overall operation as straightforward once you understand what you are measuring. There is also limited but relevant feedback that the device takes time to evaluate batteries before it ramps into faster charging, and that it is a bit bulkier than expected for everyday carrying. Overall, buyer-review evidence suggests the VX4 is less about “instant charging” and more about charging plus data-driven battery sorting.
What the XTAR VX4 is for
The VX4 Visible Mixer is aimed at rechargeable battery owners who keep more than one chemistry at home. The most notable “niche” fit is the 1.5V Li-ion AA type (often used in devices that expect an AA-sized form factor). If you also use 3.6V/3.7V Li-ion cells (for example, common Li-ion formats) and 1.2V Ni-MH rechargeables, this charger consolidates multiple needs into one unit.
Supported battery types and charging modes
Instead of being limited to a single chemistry, the VX4 is built to recognize and charge different battery types. It uses separate modes for typical categories of rechargeables:
- Default mode: auto-recognizes and charges 3.6V/3.7V Li-ion and 1.5V Li-ion, plus 1.2V Ni-MH.
- LiFePO4 mode: identifies and charges LiFePO4 (3.2V class) batteries, while still supporting 1.2V Ni-MH and 1.5V Li-ion.
For Li-ion batteries, it uses a multi-stage charging approach intended to balance fast charging with battery longevity. For Ni-MH, it includes a safety-oriented strategy (CVSA technology) designed to help manage thermal risk during charging.
Capacity testing: why the mWh screen matters
The VX4 is not only a charger, it’s also a capacity tester. The display is designed to show energy measurements, using mWh as the main unit. In practical terms, this helps you compare cells and identify which ones hold up when they are older or when you inherited a mixed set.
That is not unique to this charger, because real-world performance can be influenced by the specific cell, age, and electronics inside certain “1.5V Li-ion AA” battery designs. If you want a charger mainly for quick topping-up, this testing-first approach may feel slower than a basic charger. If you want to verify batteries before trusting them in devices, the VX4’s tester focus is the point.
Charging speed and how it behaves
With the included USB-C PD adapter, each slot supports up to 3A max current. The package notes a battery charge time around 3.3 hours for a 6000mAh battery, but real time can vary by chemistry, starting condition, and how the charger evaluates the cell. Several reviewers also describe the unit doing an analysis phase before transitioning to full charge rate, which aligns with the “tester” design rather than an instant charge style.
If you regularly charge cells on the go, the evaluation phase is worth factoring into your routine, especially when you are charging from a low or uncertain state.
Pros and cons in plain terms
Pros
- Great fit if you own multiple rechargeable battery types and especially if you need a charger that can test 1.5V Li-ion AA batteries.
- Capacity measurement helps you sort batteries by usable energy, not just by whether they “feel charged.”
- Auto-mode recognition and multi-stage charging are designed to match the battery type more appropriately than one-size-fits-all chargers.
- Safety protections and cooling-oriented design help it stay practical for repeated use.
Cons
- Not a true universal charger. It is meant for specific rechargeable chemistries only.
- Expect a bulkier footprint than “pocket chargers,” and plan for home or desk storage.
- If your expectation is that tester readings will exactly match marketing capacity labels, you may find the results underwhelming. The value is more in comparing cells and weeding out weaker ones.
Who should buy it
- You want a single charger that covers 1.5V Li-ion AA, 3.6V/3.7V Li-ion, 3.2V LiFePO4, and 1.2V Ni-MH.
- You have older, mixed, or “maybe good” rechargeable batteries and want to test energy capacity before putting them into devices.
- You prefer a charger that gives feedback on what the cell can deliver, not just a timer-based charge.
Who should avoid it
- You need a charger for alkaline batteries, Ni-Cad, or other non-supported chemistries.
- You need a very small travel charger and do not want a larger unit on the road.
- You mainly want fast, simple top-ups and are not interested in capacity testing behavior.
Alternatives to consider (by fit, not by name)
If your situation differs, the better choice may be a simpler charger:
- Choose a basic multi-chemistry charger without testing if you just want reliable charging and do not care about mWh readings.
- Choose a specialist 1.5V Li-ion AA charger if your battery collection is mostly the AA-size 1.5V type and you do not need LiFePO4 or mixed-mode support.
- Choose a LiFePO4-only charger if LiFePO4 is your primary chemistry and you want to minimize unused features.
Bottom line
The XTAR VX4 Visible Mixer is a strong option for rechargeable battery owners who want more than charging, especially if you use 1.5V Li-ion AA cells and want a way to verify capacity. It is less ideal for anyone who needs alkaline support or who expects the display to magically match advertised label capacities. If you value data-driven battery sorting and can accommodate a larger tester-style charger, it should fit well.
FAQs
Does the XTAR VX4 charger work with alkaline batteries?
No. It’s designed for rechargeable batteries in its supported list, including 1.5V Li-ion, 3.6V/3.7V Li-ion, 3.2V LiFePO4, and 1.2V Ni-MH, and it does not support alkaline chemistry.
What batteries can the XTAR VX4 test and charge?
It supports multiple rechargeables, including 1.5V Li-ion (AA-size), 3.6V/3.7V Li-ion, 3.2V LiFePO4, and 1.2V Ni-MH batteries.
How does the capacity tester display work?
The VX4 focuses on energy readings shown in mWh. This helps you compare how much energy different cells can deliver rather than relying only on the battery’s label.
Why might the measured capacity be lower than the battery’s advertised mWh?
In practice, battery performance can vary from advertised specifications due to factors like cell age, condition, and design differences, especially in batteries that incorporate internal protection or circuitry. The charger’s value is most useful for comparing cells and identifying weaker ones.
Is this charger meant for quick charging only?
It’s better viewed as a charger plus tester. Some cells may require an analysis phase before it transitions to higher charging current, so it can take longer than basic chargers when you are starting from unknown or low conditions.
Specifications
| Product Title | XTAR VX4 Visible Mixer 1.5V/3.6V/3.7V Li-Ion 3.2V LiFePO4 1.2V Ni-MH Batteries Charger and Battery Capacity Tester(Noted: Package Not Included Any Batteries, ONLY the Charger Included |
|---|---|
| Category | Electronics > Household Batteries, Chargers & Accessories > Battery Chargers |
| Brand | XTAR |
| Manufacturer | ShenZhen XTAR Electronics Co., Ltd |
| Model Number | XTAR VX4 |
| Color | Black |
| Item Weight | 315 Grams |
| Product Dimensions | 1.63"D x 5.11"W x 6.77"H |
| Output Voltage | 11 Volts (DC) |
| Input Voltage | 9 Volts |
| Battery Charge Time | 3.3 Hours |
| Current Rating | 3 Amps |
| Amperage | 3 Amps |
| Connector Type Used on Cable | USB Type-C |
| Number of Ports | 4 |
| Item Dimensions D x W x H | 1.63"D x 5.11"W x 6.77"H |
| Specification Met | CE, FCC |
| Mfr Part Number | VX4 |
| Warranty Description | 1 |
| Built-In Media | VX4 Charger, PD2.0 Adapter, C-C cable |
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