Instructions, cautions and warnings.

  • These battery packs have no a internal BMS, are intended to use with a external charger with proper protection and balancing functions for this kind of lithium-ion cells (see the page with chargers).
  • Because is a new battery pack assembled, the cells have from factory a voltage for storage state, and needs to be fully charged to 4.20V/cell before first use.
  • The cells should be kept away from heat generating electronic parts in order to avoid deterioration of battery performance.
  • For safety reason and in order not to shorten the cycle life, max charging voltage should be under 4.20V/cell including tolerance.
  • The standard charge condition is a constant current – constant voltage method with a current between 1670mA/cell (NCR18650GA), and 2000mA/cell (NCR20700B). The charging process should be automatic halted by charging device when either time, battery voltage, or current reach certain values.
  • The discharge end voltage should be more than 2.7V/cell including tolerance.
  • The charging temperature should be confined to the range 5°C to +45°C.
  • The discharge temperature should be between -20°C to +60°C.
  • The cell temperature must not exceed 70℃.

Storage temperature and humidity.

  • When long duration storage the battery packs should be stored in a stable environment characterized by low-humidity (less than 70%RH), free of corrosive gasses, and an ambient temperature between -20℃ and +20℃.
  • Avoid conditions that can create condensation such as rapid fluctuations in the ambient.

Prohibited actions.

  • DO NOT short circuit
  • DO NOT force a reverse-charge or a reverse-connection
  • DO NOT overcharge
  • DO NOT modify, disassemble, puncture, cut, crush, or incinerate
  • DO NOT expose to liquids
  • DO NOT use or place the battery a high temperatures (more than 80°C)
  • DO NOT connect the battery directly with AC plug (outlet) or electric car plugs.


When disposing of the battery, recycle it according to local rules and regulations.

Other battery safety requirements.

In order to ensure the safety of the battery pack, please contact CMEC to discuss design of the application from a mechanical and electrical perspective. Also, if there are special usage conditions (for example: a large current load, a quick charge method, or a special usage pattern), please consult CMEC before finalizing the product specification.

Warranty exemptions.

  • CMEC will not be liable for any damages that are caused by violations of the precautions in this specification
  • CMEC will not be liable for any problems caused by design defects of battery pack charger.
  • CMEC will not accept return of any abnormal battery pack that were damaged due to any incorrect cycle process.
  • Do not use the provided battery packs for UAVs, on other applications.

What shortens lithium battery life.

  1. High temperatures.cmec-batt
  2. Overcharging or high voltage.
  3. Deep discharges or low voltage.
  4. High discharges or charge current.

Prolongs the NCR battery life.

Because our goals it is to offer cost-efficient / long-life battery packs, we’ll explain a few things:
After about 500-600 cycles at 100% DOD (2.50V) and 100% SOC (4.20V), capacity of cell will drop to circa 80%. So, if you drain the battery consistently to only about 70% of entire capacity, life expectancy of a healthy battery grows up to 1500 – 2000 cycles. Also, cycling between 90% and 20% provides a longer service life than charging to 100% and discharging to 50%.

A “window” setup between 3.10V – 4.10V is right way to prolong the cell life.