The protection board is for 5 series Li-ion batteries, mainly used for electric power tools. It uses special IC for 5S lithium batteries as processor to detect real-time voltage, charge and discharge current and ambient temperature of each battery. Stable various protective functions for charging and discharging, such as overcharge protection, over-discharge protection and short circuit protection. Low power consumption,the working current is about 25uA and quiescent current is about 6uA. Choosing the correct protection board and applying it appropriately is vital to the longevity your batteries. Charge Voltage:19/21V Single Cell Charge Voltage:3.8/4.25V Continuous Discharge Current:8-20A Overcharge Single Cell Detection Voltage:3.85-4.25V Overcharge Protection Delay:1S Overcharge Single Cell Recovery Voltage 3.75-4.13V Overcharge Protection Release Delay:1mS Over-discharge Single Cell Detection Voltage:2-2.8V Over-discharge Protection Delay:1S Over-discharge Single Cell Recovery Voltage:2.5-3.0V Over-discharge Protection Release Delay:100 +/- 20mS Over-current Detection Voltage:0.1-0.4V Over-current Detection Current:30 +/- 5A Over-current Detection Delay:1S Recovery State:Auto Short Circuit Protection:Support Yes Short Circuit Detection Delay:250uS Short Circuit Release Delay:1S Short Circuit Detection Voltage 0.8V Protection Temperature:70 +/- 5 degree Recovery Temperature:55 +/- 5 degree Discharge Main Circuit Internal Resistance:30 +/- 5m ohm Operating Temperature: -40 degree-85 degree RH less than or equal to 75% Store Temperature:-40 degree-125 degree RH less than or equal to 75% Type: double MOS Colour: green Material: plastic Size: 46x40mm/1.81x1.57inch Package Contents: 1 * Battery Protection Board Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.