MP26124 4S Cell Li-Ion Battery Chargers Monolithic Power Systems MP26124 4S Cell Li-Ion Battery Chargers are switching chargers for 4-series cell Li-Ion battery packs. These battery chargers offer a monolithic design with DC/DC step-down operation. The MP26124 4S Cell Li-Ion battery chargers feature an integrated high-power 0.2Ω MOSFET, a sense resistor, multiple fault condition protections, and a programmable timer. These Li-Ion battery chargers achieve up to 2A charge current with a peak current control mode for fast loop response. The sense resistor controls the programmable charge current and accurately regulates the charge current and charge voltage by utilizing two control loops.