The 4S 14.8V 20A Lithium battery Protection Board comes with over-charge, over-discharge, over-current and short circuit protection, for a variety of various shapes 3.7V lithium-Ion batteries. It is Small size square shape board under which four 18650 cells can be packed suitable for many requirements of high integration, low cost of the occasion, to meet a wide range of performance requirements to ensure that the battery pack is absolutely safe and reliable.