When only the best NP1 is good enough, look at a DSM NP1+1SS13.2V 1.7Ah battery.

The NP1 with a Handy DC Socket for powering a 20W (max) Video Light or attaching a DSM Twin Battery over-night charger unit. We hand build each battery and fully test them in our own factory.
The extra 1.2V lets this battery deliver all its available capacity unlike 12V types that can leave up to 25% still in thebattery when the camera cuts off.

The DSM 18011CTWIN Plug-Top Battery Charger charges two DSM NP1+1 batteries overnight. Ideal for balancing cells and slow charging long term stored batteries.