|
|
|
| |
|
|
|
| why lithium battery need precharge function |
| Clicks£º585Times¡¡Back to list |
| why lithium battery need precharge function. the operating voltage of the battery ranges from 2.5 V (carbon negative battery :3 V, charge 0%) to 4.2 V( charge 100%). battery discharge terminates when the voltage is less than 2.5 V. At the same time, the current loss of the internal protection circuit is minimized because the discharge circuit is closed. of course, the discharge termination voltage can be in the range of 2.5 V-3.0V in practical applications due to different internal materials. when the voltage exceeds 4.2 V, the charging loop terminates to protect the battery safety; while when the operating voltage of the single cell drops below 3.0 V, we can consider the over-discharge state and the discharge loop terminates to protect the battery safety. So when the battery is not used, the battery should be charged 20% of the electricity, and then moisture-proof preservation. Because the lithium ion battery has a high energy ratio, it is necessary to strictly avoid the phenomenon of overcharge and over-discharge in the use of the battery. Over-discharge can lead to the recovery of the active material difficult, at this time if directly into the fast impulse mode (high current), will cause damage to the battery, affect the service life and may lead to safety risks. Small current (C/10) charge to 2.5 V to 3.0 V, before conversion to fast charge is necessary. Although the current lithium ion battery in the application with a protective plate, in the usual case, the probability of over-discharge will be very small, but without pre-charge function, in these two cases may still bring the hidden danger of over-discharge. One is the failure of the protection plate, the other is the self-discharge rate of long time placement (5%-10%/ month). So small current precharge can effectively solve the charging problem of over-discharge pool. but the charging current is not as big as possible. Take the single lithium ion battery as an example, its charging mode includes constant current, constant voltage charging process, constant voltage is usually 4.2 V (take LiCoO2 battery as an example), constant current setting value is 0.1 C~1 C.. Although charging with high current will shorten the charging time, it will also cause the shortening of battery life cycle and the reduction of capacity, so we need to choose the appropriate constant current value for charging. |
|
|
|
|
|
|
|
|
