Nitecore UM4 - User Manual

UM4
• Automatic and High-Speed Charging
• Real-time Information Display
• Over-Discharged Li-ion Battery Activation
and IMR Battery Restoration
Intelligent USB
Four-Slot Charger

Summary

Nitecore UM4 Charger Overview

Product Features and Specifications

Key Features of the UM4 Charger

Lists intelligent USB charging, QC 2.0 input, independent slot control, high speed charging, and automatic detection.

Included Accessories

Details the accessories provided with the charger, such as the USB charging cable.

Technical Specifications

Covers input/output, charging modes, compatible batteries, dimensions, and weight.

User Operating Instructions

Connecting to Power and Inserting Batteries

Guide on connecting the charger to a power source and inserting batteries correctly.

Battery Inspection and Error Handling

Explains how the charger detects battery issues like reverse polarity or short circuits.

Charging Modes and Settings

Details automatic and manual settings for charging current, voltage, and modes.

Advanced Charging Functions

Covers battery activation, IMR restoration, internal resistance detection, and overtime protection.

General Precautions for Safe Use

Lists essential safety warnings and operating guidelines for the charger and batteries.

Lithium-ion Battery Safety Guidelines

Charging Voltage Requirements

Specifies correct charging voltages for 3.7V, 3.8V Li-ion, and 3.2V LiFePO4 batteries.

Charging Current Recommendations

Advises on selecting appropriate charging currents (1C rule) to prevent battery damage.

Safety Precautions for Lithium Batteries

Highlights critical safety points like avoiding short circuits and over-discharge.

Long-term Battery Storage

Provides guidance on optimal storage voltage for rechargeable lithium batteries.

Overview

1. Function Description
2. Usage Features
3. Maintenance Features

The NITECORE UM4 is an intelligent USB four-slot charger designed for efficient and safe charging of various rechargeable batteries. It is engineered with advanced features to provide a comprehensive charging solution for users.

Function Description

The primary function of the UM4 is to charge up to four batteries simultaneously and independently. It supports a wide range of battery chemistries, including Li-ion, IMR, LiFePO4, and Ni-MH/Ni-Cd batteries. The charger automatically detects the battery type and selects the appropriate charging mode (CC, CV, and -dV/dt) and voltage, with the exception of LiFePO4 and 3.8V Li-ion batteries, which require manual voltage settings.

A key feature of the UM4 is its intelligent USB input, which supports QC 2.0, allowing for high-speed charging. In QC mode, a single slot can achieve a charging speed of up to 1,500mA, and two slots can reach 1,500mA each, while four slots can charge at 750mA each. In standard mode, a single slot can charge at 1,500mA, two slots at 1,000mA each, and four slots at 500mA each. This flexibility ensures efficient charging whether one or multiple batteries are being charged.

The UM4 includes an energy-efficient LCD display that provides real-time charging information. This display shows crucial data such as battery health (rated as "Good" or "Poor"), internal resistance, charging current, battery voltage, charged volume, and charging time. This allows users to monitor the charging process and assess the condition of their batteries.

Safety is a paramount concern in the design of the UM4. It incorporates several protection mechanisms, including reverse polarity protection and short circuit protection, which prevent damage to the charger and batteries if batteries are inserted incorrectly or if a short circuit occurs. The charger also features over-discharged Li-ion battery activation, which can revive Li-ion batteries with protective circuits that have been deeply discharged. Additionally, it offers IMR battery restoration for over-discharged IMR batteries, although users are cautioned about temporarily disabled reverse polarity protection during this process.

The charger automatically terminates charging upon completion to prevent overcharging and includes overtime charging protection, which stops charging a slot if the process exceeds 20 hours, thereby preventing potential overheating or explosion due to battery quality issues. The UM4 also detects and displays the battery's internal resistance, providing an indication of battery health and suggesting replacement if the resistance is too high.

Usage Features

Operating the UM4 is straightforward. Users connect the charger to a power source via a USB charging cable. Once batteries are inserted, the charger automatically begins the charging process.

The LCD display is central to the user experience, offering a wealth of information. Users can cycle through the charging status of the four slots by short-pressing the 'C' button. Short-pressing the 'V' button allows users to cycle through various battery parameters on the display, including Battery Health, Internal Resistance, Charging Current, Battery Voltage, Charged Volume, and Charging Time.

For advanced users, the UM4 offers manual control over charging parameters. By long-pressing the 'C' button, users can enter the Charging Setting Mode. Within this mode, short-pressing 'C' switches between setting the Charging Current and Cut-Off Voltage. Short-pressing 'V' increases the charging current in 100mA increments or switches between different battery types and voltage readings. A long press of 'V' directly accesses the maximum setting for the charging current. Settings can be saved and exited by long-pressing 'C'. If no action is taken for 10 seconds, the charger automatically exits the Charging Setting Mode without saving.

For LiFePO4 and 3.8V Li-ion batteries, manual selection of the charging cut-off voltage is required. This involves entering the Charging Setting Mode, selecting the correct slot, and then using the 'V' button to choose the appropriate voltage (3.7V for LiFePO4 and 4.3V for 3.8V Li-ion).

The UM4 also includes an energy-saving function: if there is no button activity or battery interaction for 3 minutes, the screen automatically dims to conserve power. Any action will reactivate the display.

Maintenance Features

The UM4 is constructed from durable and fire-retardant PC materials, ensuring longevity and safety. Its optimal heat dissipation design helps manage temperature during charging, contributing to the device's reliability.

While the manual does not detail specific user-performed maintenance, it emphasizes several precautions to ensure the device's proper functioning and safety. Users are advised to:

• Only charge compatible battery types to avoid explosions, cracking, or leaking.
• Avoid leaving the product unattended while connected to a power supply.
• Ensure correct program and settings are chosen to prevent damage or fire.
• Not charge damaged IMR batteries or batteries showing signs of leakage, expansion, or damage.
• Use the original adapter and cord for power supply to prevent damage.
• Avoid exposing the device to direct sunlight, extreme temperatures, or moist environments.
• Store the device in ventilated areas and avoid physical shock or impact.
• Not place conductive or metal objects in the device.
• Avoid overcharging or over-discharging batteries; recharge them as soon as power runs out.
• Unplug the device and remove batteries when not in use.
• Not disassemble or modify the device, as this will void the warranty.

The device is certified by RoHS, CE, FCC, and CEC, indicating compliance with international safety and environmental standards. It is also insured worldwide by Ping An Insurance (Group) Company of China, Ltd., providing an additional layer of assurance for users. The warranty details specify that unauthorized modifications or improper operations will nullify the warranty, reinforcing the importance of adhering to the usage guidelines.

Nitecore UM4 Specifications