Nitecore UMS2 Intelligent Dual-Slot Quick USB-C Battery Charger for Li-Ion/Ni-MH/Ni-Cd/IMR
Quick take
The Nitecore UMS2 is a dual-slot USB-C charger meant for people who own multiple rechargeable battery types, including common Li-ion/IMR sizes (like 18650 and 16340) and Ni-MH/Ni-Cd AA and AAA cells. It charges through the USB-C input, shows real-time status on its LCD, and uses intelligent charging to pick appropriate parameters. The biggest buying caveat is that charging speed is tied to the USB power adapter you supply, and the charger setup does not include a wall plug.
Pros and cons
Pros
- Dual-slot design supports many batteries, including IMR/Li-ion/LiFePO4 (various sizes) plus AA/AAA Ni-MH and Ni-Cd.
- USB-C powered charging, useful for travel and setups that rely on portable power.
- LCD display provides live charging and battery information, including charging mode and battery health details.
- Intelligent charging automatically selects appropriate charging current and voltage to help protect batteries.
Cons
- Maximum charging speed depends on your USB power source, so a slower adapter can reduce how fast your cells fill.
- No wall plug is included, so you will likely need a compatible USB adapter for best results.
- There can be noticeable electrical squeal during operation for some users, so it may not be ideal if you are sensitive to noise.
What buyers think
Buyer-review evidence points to strong satisfaction with charging speed and convenience, especially for 18650 users upgrading from older chargers. Many reviews highlight the LCD’s usefulness, with buyers mentioning that the charger shows more than basic “charging vs not charging” information. Several shoppers also appreciate the charger’s intelligence, including automatic detection and mode behavior, and they describe the battery bays as easy to adjust for different sizes. That said, review evidence is limited on long-term durability, and there is at least one recurring noise concern reported as an electrical squeal during charging.
How the Nitecore UMS2 fits common battery collections
This charger is built for mixed-battery households and EDC setups. It supports widely used cylindrical Li-ion/IMR sizes, including 16340, 14500, 18650, 20700, and 21700 families, plus other listed Li-ion/IMR and LiFePO4-compatible sizes. It also supports Ni-MH and Ni-Cd formats like AA and AAA, with additional listed sizes (such as AAAA, C, and D) for broader compatibility depending on the cell.
The dual-slot layout is the practical part for day-to-day use: you can charge two cells at once, which is helpful if you run multiple flashlights, headlamps, or other rechargeable devices that share the same chemistry.
Charging speed and power-source expectations
The UMS2 can reach a maximum total of 4000mA for two slots, and up to 3000mA when charging one slot, if your USB power source is capable. Per-slot charging current can reach up to 1000mA when paired with a standard 5V/2A USB source, and the listing also calls out faster behavior when using a 9V USB power source that supports QC2.0+.
What this means for buyers: if your priority is “fast,” you should plan to use a USB adapter that meets the charger’s expectations. If you use a lower-powered charger, you should still expect it to charge, but not at the higher current levels described for peak performance.
LCD display and intelligent charging
The charger includes an LCD that reports real-time information such as battery health, charging status, and charging mode. Buyers also describe the screen as informative, including details that go beyond a simple indicator light.
On the safety and longevity side, it uses intelligent charging logic to automatically select appropriate charging current and voltage for the connected cell. It is also described as capable of restoration and activation workflows for over-discharged IMR cells, with behavior controlled through the charger’s buttons (for example, long-press modes for restoration/activation and manual charging setting access).
Portability and included organizer
The UMS2’s USB-C approach can simplify travel because it can run from many mobile power sources and USB adapters, rather than requiring a dedicated bulky AC charging brick. The package includes a 2-battery organizer, which helps keep loose cells contained and reduces “find the right battery size later” friction while on the go.
One limitation to plan for, however: you will need your own USB power adapter (the reviews and listing context emphasize USB-C connection use, but the practical constraint is that many shoppers will still want a suitable wall adapter or power bank).
Battery compatibility checklist (so you do not buy the wrong charger)
- Confirm chemistry: the charger is meant for listed Li-ion/IMR/LiFePO4 and Ni-MH/Ni-Cd rechargeable cells.
- Confirm size: check that your battery sizes match the listed supported formats (for example 18650, 16340, 14500, AA, AAA, etc.).
- Plan your power source: for maximum speed, use a USB adapter that can deliver the higher USB modes referenced (for example 9V QC2.0+ for faster operation, or a sufficiently capable 5V/2A supply).
Pros and cons for different types of buyers
Best for
- People who own multiple battery types, especially a mix of cylindrical Li-ion/IMR cells and AA/AAA Ni-MH or Ni-Cd.
- Travel and EDC users who prefer USB-C charging over dedicated wall chargers.
- Buyers who want more information on-screen than basic “charged/not charged” indicators.
Who should avoid it
- Shoppers who expect it to reach peak charging speed with a low-power USB port or generic charging brick.
- Anyone who is very sensitive to electrical noise while charging (some users report a squeal).
- Those who want a single-chemistry charger only, since this model’s value is strongest when you actually need its multi-chemistry, multi-size support.
Verdict
The Nitecore UMS2 is a strong choice if you want one compact dual-slot USB-C charger that can handle a broad set of common rechargeable batteries, with an LCD that helps you keep track of charging behavior and battery health. To get the performance you are paying for, pair it with an appropriate USB power adapter, since charging speed is limited by input power. If noise is a concern and you charge in quiet spaces, consider the tradeoff before buying.
FAQ
Does the Nitecore UMS2 come with a wall charger?
The charger uses a USB-C input, and you will need a compatible USB power adapter (wall plug or power bank) to charge at the level described for your setup.
What batteries does the UMS2 support?
It is designed for multiple rechargeable battery chemistries, including Li-ion/IMR and LiFePO4 cylindrical cells (in many listed sizes such as 16340, 14500, 18650, 20700, and 21700 families) as well as Ni-MH and Ni-Cd cells including AA and AAA, with additional listed sizes.
How fast does it charge?
Peak performance depends on your USB power source. The listing describes a maximum total of 4000mA across two slots, 3000mA for one slot, and up to 1000mA per slot when using a standard 5V/2A USB source, with faster behavior possible when paired with a 9V QC2.0+ output.
What does the LCD display show?
The LCD is used to show real-time charging information, including battery health, charging status, and the charging mode.
Is there any downside compared with simpler chargers?
If you only use one battery size and one chemistry, simpler single-purpose chargers can be cheaper and easier. Also, charging speed depends on your USB adapter, and some buyers report an electrical squeal during operation.
Specifications
| Product Title | Nitecore UMS2 Intelligent Dual-Slot Quick USB-C Battery Charger for Li-Ion/Ni-MH/Ni-Cd/IMR 16340 14500 18650 21700 20700 AA AAA and More Batteries, with Organizer |
|---|---|
| Category | Electronics > Household Batteries, Chargers & Accessories > Battery Chargers |
| Brand | Nitecore |
| Manufacturer | NITECORE |
| Model Number | UMS2 |
| Color | Black |
| Item Weight | 5.56 Ounces |
| Product Dimensions | 2.87"D x 5.98"W x 1.57"H |
| Output Voltage | 4.35 Volts |
| Input Voltage | 5 Volts |
| Current Rating | 2 Amps |
| Amperage | 3000 Amps |
| Compatible Devices | IMR/Li-ion/LiFePO4: 10440, 14500, 14650, 16500, 16340(RCR123), 16650, 17350, 17500, 17650, 17670, 17700, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22500, 22650, 25500, 26500, 26650, 26700, Ni-MH/Ni-Cd: AA, AAA, AAAA, C, D |
| Connector Type Used on Cable | USB |
| Number of Ports | 2 |
| Item Dimensions D x W x H | 2.87"D x 5.98"W x 1.57"H |
| Mfr Part Number | UMS2+ORG |
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