One of the most important companies in India that makes and sells lithium-ion battery chargers is OGO Energy Private Limited. We make and sell the best lithium-ion battery chargers that work well and last a long time. A system called constant voltage or constant current charge is what makes lithium battery chargers work. The charger will only send a set amount of power until the battery hits a set energy level. As the battery gets fully charged, the power goes down.