The best way to extend the operational life of virtually all types of NP-style Lithium Ion batteries is to use the JL-2PLUS, which charges 2 NP batteries sequentially with unrivalled high speed and reliability.
The JL-2PLUS can be used just about anywhere space is at a premium, from the production studio to location shoots. In this environment, the JL-2PLUS's built-in 60W AC adaptor becomes areal advantage.
IDX-CA4XLR-B is required and sold separately.