(English) UMS2 User Manual
Safety Instruction for Lithium-ion Batteries
1. Charging Voltage
Lithium-ion (Li-ion) batteries have strict requirement on voltage control. Charging Li-ion batteries with electric voltage
beyond safety standard can lead to battery damage and explosion.
(1) 3.7V Li-ion Batteries / IMR Batteries
3.7V Li-ion batteries are the most common rechargeable Lithium batteries. The skins of these batteries are often
marked with 3.6V/3.7V signs. If our chargers judge that an inserted battery is a Li-ion battery, the battery will be
automatically charged in 4.2V standard charging mode. You do not need extra voltage settings for these types of
batteries.
(2) 3.8V Li-ion Batteries
3.8V Li-ion batteries are comparatively rare. It usually has a 3.7V mark on its skin. Normally its seller will inform
its buyer that it needs to be charged with 4.35V power. When charging this type of battery, please manually set
the charging voltage to 4.3V, otherwise the charger will charge at 4.2V by default, and cannot provide adequate
charging voltage.
(3) 3.2V LiFePO4 Batteries
3.2V LiFePO4 batteries have LiFePO4 and/or 3.2V marks on the skin. Be careful with this type of batteries. Without
manual setting, our chargers will charge this type of batteries with 4.2V, and will damage or even explode the
battery with excessive charging voltage. You need to manually set the charging voltage to 3.7V for safe charging.
2. Charging Current
For all rechargeable Lithium batteries (including Li-ion, IMR and LiFePO4 batteries), we suggest not using current
larger than 1C* for charging. For small capacity batteries, the charging current must be smaller than 1C.
* C=Capacity of a battery. For example, 1C in a 2600mAh rechargeable Lithium battery is 2.6A. 1C in a 3400mAh
rechargeable Lithium battery is 3.4A.
Excessively large charging current will lead to great amount of heat, and consequently battery damage and explosion.
Warning:
Our chargers automatically judge and select charging current by the batteries’ length. For some
long but small capacity batteries (i.e. 12650, 13650, 14650, 16650), please manually set appropriate
charging current (smaller than 1C).
3. Precautions
(1) DO NOT short circuit the battery in any way.
(2) DO NOT use a 3.7V/3.8V Lithium battery when its voltage is lower than 2.8V, otherwise it can be over-discharged,
and/or prone to explosion at next charging.
(3) We strongly recommend batteries with protective circuit. For batteries without protective circuit (such as IMR
batteries), please stay alert for over-discharge and short circuit.
(4) DO NOT discharge a battery with a discharging current larger than its maximum rated current.
4. Long-term Storage
The best storage voltage for 3.7V/3.8V rechargeable Lithium batteries is 3.7V. Voltage too low or too high can damage
your battery during storage. You can discharge a battery to 3.7V, or charge it to 3.7V in a charger before you keep it
in long-term storage.
Validation code and QR code on package can be verified on NITECORE website.
The charger must be used with NITECORE’s official cords. Official cords are identified with clearly printed
NITECORE on the plug. During charging, third party cords can cause malfunction, overheat and even fire
on the charger. Damages from using unofficial cords cannot be covered by official warranty.
The charger is restricted to charging Li-ion, IMR, 3.2V LiFePO4, Ni-MH/Ni-Cd rechargeable batteries only.
DO NOT use the charger with other types of batteries as this could result in battery explosion, cracking or
leaking, causing property damage and/or personal injury.
