Difference between common port and different port of lithium battery protection board BMS?

2021-08-04 14:25:33 0

The Battery management system BMS is used to protect the charge and discharge of the series lithium battery pack; When fully charged, it can ensure that the voltage difference between each single battery is less than the set value (generally 20mV), realize the equal charging of each single battery of the battery pack, and effectively improve the charging effect under the series charging mode; At the same time, the over-voltage, under-voltage, over-current, short circuit and over-temperature states of each single battery in the battery pack are detected to protect and prolong the service life of the battery; Under voltage protection enables each single battery to avoid battery damage due to over discharge. So what's the difference between the common port and the different port of the Battery management system BMS?

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The common port refers to the same interface for charging and discharging, that is, only two wires are used.

Split means that charging and discharging are separated, and three wires are required.

The disadvantage of the common port is that the MOS of charge control and discharge control on the battery protection board are the same. During discharge, the current will pass through the charge control MOS, which increases the cost, internal resistance and heat.

In general, the battery discharge current is much larger than the charging current, so the MOS with smaller current can be selected for the split charging control MOS. The discharge and charging do not affect each other. The disadvantage is that there is one more line, which is not suitable for use in some occasions.

The charge control module and discharge control module of the lithium battery charge and discharge protection board control the charge and discharge by controlling the on-off of the MOS tube. First, check whether the charge switch tube (NOMs) is damaged;

Secondly, there are generally short circuit module and charge discharge current detection module on the protection board. If the charging current is large, the circuit will automatically enter the sleep mode. At this time, the charging current has been considered for the general supporting chargers, which will not cause the circuit locking caused by excessive charging current.