Magnum Energy's MS series inverter/charger-a pure sine wave inverter designed for the most demanding mobile, backup and off-grid applications. The MS series is powerful, easy to use, and most importantly, cost-effective. Power factor correction (PFC) charger: Our PFC charger is built into all our inverters/chargers. Compared to a standard charger, it consumes less energy from the generator-compared to a standard charger, it uses 25-30% less AC current.