and high quality. 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 protective functions for charging and discharging, such as overcharge protection, over-discharge protection and short circuit protection. Choosing the correct protection board and applying it appropriately is vital to the your batteries. Charge Voltage: 21V Charging current: 3 A Discharge current: 40 A Over charge protection current: 7A+/-2A Over discharge protection current: 66A+/-5A (Adjustable) Single Cell Overcharge protection voltage: 4.25V+/-25MV Single Cell Over discharge protection voltage: 2.7V+/-80MV size:78x46mm Material:PCB+Plastic+Metal colour:Green Package Contents: 5 x Battery Charger Protection Board Only 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.