Nitecore UMS2 two-bay USB charger with its box, user manual and USB cable

Nitecore UMS2 box: QC 2.0 Available, 3A Speedy Charge, two batteries in the charger

Nitecore UMS2 charger from above: the LCD, the C and V buttons and two empty bays

Nitecore UMS2 charger from a low angle, showing its finned sides

Nitecore UMS2 charger at an angle with its USB cable

Fall Clearance

Nitecore 3A UMS2 USB Dual Slot Charger

Name: Vape Society Supply
Price range: $$

Brand: Nitecore

Original price was: $34.99.Current price is: $19.99.

Fall Clearance price, already marked down. Codes don’t apply. While supplies last.

The Nitecore 3A UMS2 USB Dual Slot Charger is a two-bay USB charger with an LCD readout for Li-ion, IMR, LiFePO4, Ni-MH and Ni-Cd batteries, including 21700s. It charges at up to 3A from a Quick Charge adapter.

In stock

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Description

Nitecore 3A UMS2 USB Dual Slot Charger Review

The Nitecore 3A UMS2 USB Dual Slot Charger is a two-bay USB charger for Li-ion, IMR, LiFePO4, Ni-MH and Ni-Cd batteries, including 18650s and 21700s. Its LCD shows each battery’s voltage, current, capacity and internal resistance, and it charges one battery at up to 3A from a Quick Charge adapter. See more from Nitecore or browse all battery chargers.

UMS2 Highlights

LCD Readout

The screen shows each battery’s voltage, charging current, charged capacity and charging time, plus its internal resistance and a Good or Poor health rating.

Up to 3A

With a Quick Charge 2.0 adapter, one battery charges at up to 3A or two at 2A each. On a standard 5V 2A adapter, it’s 2A for one or 1A each for two.

Set Current and Voltage

The UMS2 picks the current and charge mode itself. Hold C to set the current, in 100mA steps, or the cut-off voltage, such as 3.7V for LiFePO4.

IMR Restoration

Holding V starts a restoration mode for over-discharged IMR batteries. Nitecore warns that reverse polarity protection is off during it, so put the battery in the right way.

UMS2 Specs

Charging

Bays: 2
Batteries: Li-ion, IMR, LiFePO4, Ni-MH and Ni-Cd
Charge voltage: 4.35V, 4.2V, 3.7V or 1.48V
Charge current: up to 3A (see the table)
Charging modes: CC, CV and −dV/dt, chosen automatically

Battery Sizes

Li-ion, IMR, LiFePO4: 24 sizes from 10440 to 26700, such as 16340 (RCR123), 18350, 18650, 20700, 21700 and 26650
Ni-MH, Ni-Cd: AA, AAA, AAAA, C and D

UMS2 Charger

Input: USB, 5V 2A, or up to 18W from a Quick Charge adapter
Display: LCD with health, internal resistance, voltage, current, capacity and time
Buttons: C and V
Protection: reverse polarity, short circuit and a 20-hour cutoff per bay, with an automatic stop
Size: 152 × 73 × 40mm
Weight: 157.7g without the cable
Body: fire-retardant PC

UMS2 Charge Current

Nitecore’s manual gives these maximum currents:

Batteries charging	Quick Charge adapter	Standard 5V 2A adapter
1	3A	2A
2	2A each	1A each

By default it charges big Li-ion batteries at 1.5A on Quick Charge or 1A on standard USB, and small batteries and Ni-MH cells at 500mA.

Batteries

Charge only rechargeable Li-ion, IMR, LiFePO4, Ni-MH or Ni-Cd batteries, never alkaline or CR123A cells, and don’t leave the charger unattended while it’s plugged in.

How to Use the UMS2

Plug it in: connect the USB cable from the box to a USB wall adapter (not included). A Quick Charge 2.0 adapter unlocks the full 3A.
Load the batteries: insert each battery with its ends matching the + and − marks. The UMS2 checks it and starts charging.
Change settings if needed: hold C to set the current or cut-off voltage, press V to adjust, then hold C again to save. LiFePO4 and high-voltage Li-ion need the voltage set by hand.
Read the screen: press C to switch between the two bays and V to step through the readings.

Who the UMS2 Is For

The Nitecore UMS2 suits vapers who want to check each battery’s health and internal resistance while it charges, in a two-bay charger for 18650 and 21700 batteries that runs from USB. For four bays, see the UMS4.

Good to know: No wall adapter comes in the box, and you need a Quick Charge adapter for 3A; on a standard 5V 2A adapter it tops out at 2A.

What’s in the UMS2 Box

Nitecore UMS2 charger
USB charging cable
User manual

FAQ

Nitecore UMS2 FAQ

Does it charge 21700 batteries?

Yes. Nitecore lists 20700, 21700 and 26700 batteries, along with 18650s and 26650s. We sell IMREN 21700 batteries in 2-packs.

How fast does it charge?

Up to 3A for one battery or 2A each for two with a Quick Charge adapter, or 2A for one and 1A each for two on a standard 5V 2A adapter.

What does the screen show?

Each battery’s health (Good or Poor), internal resistance, charging current, voltage, charged capacity and charging time. Press V to step through them and C to switch bays.

Does it come with a wall adapter?

No. It comes with a USB cable. Use a Quick Charge 2.0 adapter for up to 3A, or a standard 5V 2A USB adapter for up to 2A.

Can it charge LiFePO4 and Ni-MH batteries?

Yes. It detects Li-ion and Ni-MH batteries itself; for LiFePO4, hold C and set the cut-off voltage to 3.7V.

How is it different from the UMS4?

The UMS4 has four bays and the same LCD and buttons. With four batteries in, it charges each at 1A on Quick Charge or 500mA on standard USB.