Li-Po Battery Operating Instructions
  

The description given below is for a battery pack composed of a single cell for reference.

Charging

General

  1. Charging Method:
    The Polymer batteries are to be charged using a Constant Current / Constant Voltage ( CC / CV ) type dedicated charger. The constant current mode is applied until the battery voltage has reached to 4.2V. Thereafter charging mode is changed to Constant Voltage and the charging current will be tapered off to where charging terminates at 1 / 20 C for maximum capacity.Charging Current, Voltage and Cut-off Control:
    Charge the battery at a constant current of 0.5C until 4.2    ±0.05V per cell is attained. Charge rate greater than 1C is not recommended. ( C = rated capacity of battery ) . Maintain the charge voltage to 4.2V per cell, and the charging must be cut-off when the current diminishes to 1 / 20 C. Allowing the current to diminish to less than 1/20C is prohibited. Charging Temperate:
    Charge the polymer battery within a temperature range of 0 to 45     ℃ . At the temperature of less than 0 ℃ or higher than 45 ℃, the battery may not only fail to be charged sufficiently, but its performance might also deteriorate in various ways.
  2. Capacity and Voltage of Battery Pack:
    Capacity of pack = capacity of single cell x numbers of cell connected in parallel; Output Voltage of pack = 3.7V x numbers of cell connected in series.

Protection Circuit of Battery Pack

To ensure peak battery performance and maximum cycle life, Fully recommends that Polymer rechargeable batteries are assembled in a battery pack with a protection circuit ( PCM ) . In packs, thermistors for detection of battery temperature, thermostats, and temperature fuses for protection from abnormal temperature are recommended to provide as a standard. The PCM must include the following function:

  1. Overcharge Protection
    There is a maximum voltage threshold of 4.25 ± 0.025V. If the maximum charging voltage is surpassed, the protection circuit will interrupt or stop charging.Overdischarge Protection
    Voltage threshold less than 2.5V is not recommended. If the battery is discharged below the cut-off voltage, the protection circuit will stop discharging.
  2. Overcurrent Protection
    If current exceeds the battery rating or recommendation's flows during charging or discharging, the charging or discharging processes will be stopped.

Functions and Performance Required for Polymer Battery Charger

  1. Charging Voltage between the terminals must be 4.2 ± 0.05V . In principle, it is desired to charge the Polymer battery at 4.2V, the specified tolerance is provided for variations in equipment, design and fabrication.Standard charging current:0.5C;Maximum charging current:1CThe charger should take into account that the temperature of Polymer batteries will rise by approx. 5 ℃ while the batteries are being charged at a strong current rate. After switching to the constant voltage charging mode, the cell temperature will gradually descrease.The charger must check the open-circuit voltage ( OCV ) of the battery pack before charging. When the OCV is measurable ( That is, the PCM allows the battery to discharge ) , the fast charging may start immediately . If the OCV is not measurable ( that is, the PCM prohibits the discharge ) , feed a small inspection current ( 0.01 - 0.7C ) so as to release the battery from the discharge prohibition mode. Then check the battery pack voltage, if a voltage of 1.5V or more is detected, then proceed to normal charging. Tf the OCV is not detected when the small inspection current is fed, the battery should be deemed abnormal and charging should be avoided.Whether the Polymer battery is fully charged should be determined by detecting the charging current. A detected current of 0.1CmA indicates that the battery is charged to 93% to 94% of its capacity.Protection Features: ( A ) If the charging voltage gets out of the range of between 1.5V and 4.3V, the battery should be deemed abnormal and charging should be avoid. ( B ) If the battery voltage remains at less than 1.5V for a specified duration of time in the trickle-charging mode during battery check, the battery should be deemed abnormal and charging should be avoided. ( C ) The Polymer battery is not allowed for trickle charging, it is recommendable to provide the timer for safety purposes.
  2. To prevent an over-voltage to the battery in the event of a malfunction in the power supply unit, select the unit equipped with over-voltage protection.

Discharging

  1. Recommended cut-off voltage to 3.0V for standard series battery, 2.5V ~ 2.75V for high power " P " series battery. The discharge rate do not exceed the max. continuous discharge rate specified in the specifications.
  2. Discharge temperature range is -20 ℃ to + 60 ℃. For maximum performance of our high power series battery, 20 ℃ to 30 ℃ is recommended.
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