The protection board is for 5 series Li-ion batteries, mainly used for electric 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 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:19/21VSingle Cell Charge Voltage:3.8/4.25VContinuous Discharge Current:8-20AOvercharge Single Cell Detection Voltage:3.85-4.25VOvercharge Protection Delay:1SOvercharge Single Cell Recovery Voltage 3.75-4.13VOvercharge Protection Release Delay:1mSOver-discharge Single Cell Detection Voltage:2-2.8VOver-discharge Protection Delay:1SOver-discharge Single Cell Recovery Voltage:2.5-3.0VOver-discharge Protection Release Delay:100 +/- 20mSOver-current Detection Voltage:0.1-0.4VOver-current Detection Current:30 +/- 5AOver-current Detection Delay:1SRecovery State:AutoShort Circuit Protection:Support YesShort Circuit Detection Delay:250uSShort Circuit Release Delay:1SShort Circuit Detection Voltage 0.8VProtection Temperature:70 +/- 5 degreeRecovery Temperature:55 +/- 5 degreeDischarge Main Circuit Internal Resistance:30 +/- 5m ohmOperating 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 MOSColour: greenMaterial: plasticSize: 46x40mm/1.81x1.57inchPackage Contents:4 x Battery Protection BoardOnly the above package content, other products are not included.Note: Light reflection 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.