This product uses a 5-cell lithium battery-specific IC as a processor to detect each battery's voltage, charge and discharge current, and ambient temperature in real time. Realize battery overcharge, over discharge, discharge overcurrent and other protection functions It has protection functions such as short circuit, over-current and temperature protection The circuit board is of , and the copper hardware and thickened terminals are It does not generate heat during long-term use and is commonly used in for lithium-electric angle grinder battery packs. Charging voltage: 19 or 21V Single charge voltage: 3.8 or 4.25V Continuous discharge current: 8-30A 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 Specification:C:OLT-MT5S90A Colour: Material:PCB Package Contents: 1 x Battery 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.