Superior quality battery with protection circuit to prevent overcharging, over-discharging, over-voltage, and short circuits, extending its lifespan. This protection board utilizes a protection circuit, special IC, and imported high-current, ultra-low internal resistance MOS for perfect and stable charging and discharging protection functions. High capacity and current make it suitable for high-current applications like electric vehicles and model aircraft. Lines B and C require thick cables, ensuring proper welding to the positive and negative terminals of the corresponding equipment. For optimal installation, the battery should be well-matched (voltage difference between each battery not exceeding 0.05V, internal resistance not exceeding 5mΩ, capacity difference less than 30mAh). Better battery consistency leads to a longer battery life and improved protection board performance. This protection board is not suitable for lithium iron phosphate batteries. It is strictly forbidden to use lithium battery protection boards in series. Color: Red Material: Plastic Package Contents: 5 * 5S 21V 18650 BMS Lithium-ion Battery Protection Board Note: Only the above package content is included; other products are not. Light photography and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowable measurement error is +/- 1-3 cm. 2X for 1992-1998 Power Window Switch 1H0959855C Car Accessories