SMAKN 4.2 4.35 3.6 Lithium/Lithium Iron Switch Buck Charging Board, 4A 8A Large Current Input voltage: 5-19V (maximum rated 20V, we recommend the use of less than 16V). Charging cut-off voltage: 4.2V, 4.35V 3.6V third gear adjustable jumper. Charging current: 4A, 8A two tranches (4A gear center about 3.8A, 8A gear center around 8.3A). Pre-charge current: Charge current 10%. Off current: 10% of the charging current.