Custom Lithium ion Battery Pack

Talk about the six main parameters of lithium batteries

Feb 11, 2019   Pageview:23

1, battery capacity

 

The capacity of the battery is determined by the amount of active material in the battery, usually expressed in milliampere-hours MAH or Ah. For example, 1000mAh can be converted to 1600 by the current discharge of 1A to a charge of about 3600C.

 

2, the nominal voltage

 

The potential difference between the positive and negative terminals of the battery is called the nominal voltage of the battery. The nominal voltage is determined by the electrode potential of the plate material and the concentration of the internal electrolyte.

 

The lithium discharge diagram is parabolic, with 4.3V dropping to 3.7V and 3.7V down to 3.0V, all of which change very quickly. Only the discharge time of about 3.7V is the longest, which accounts for almost 3/4 of the time. Therefore, the nominal voltage of the lithium battery refers to the voltage that sustains the discharge time for the longest period.

 

The nominal voltage of a lithium battery is 3.7V and 3.8V. If it is 3.7V, the charge termination voltage is 4.2V. If it is 3.8V, the charge termination voltage is 4.35V.

 

3, charging termination voltage

 

When the rechargeable battery is fully charged, the active material on the plate has reached saturation, and then continues to charge, and the voltage of the battery does not rise. The voltage at this time is called the charge termination voltage. The lithium ion battery is 4.2V or 4.35V.

 

4, discharge termination voltage

 

The discharge termination voltage is the lowest voltage allowed when the battery is discharged. The discharge termination voltage is related to the discharge rate. Generally, the unit lithium ion battery is 2.7V.

 

5, battery internal resistance

 

The internal resistance of the battery is determined by the resistance of the electrode plate and the resistance of the ion flow. During the charging and discharging process, the resistance of the image engine and the electrode plate is constant, but the resistance of the ion flow will change with the increase and decrease of the electrolyte concentration and charged ions. When the OCV voltage of the lithium battery is lowered, the impedance will increase. Therefore, when charging at low power (less than 3V), pre-charging (choke charging) is required to prevent the battery from generating too much heat due to too much current.

 

6, self-discharge rate

 

It refers to the percentage of total capacity lost automatically when the battery is not in use for a period of time. Generally, the self-discharge rate of a lithium ion battery at a normal temperature is 5% to 8%.

 

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