Godox Spare Battery for PB960 Spare Lithium battery pack quickly clips on and off the base of the PB960.
Probably one of the most important features of the PB960 is the removable battery.
The actual Lithium battery pack quickly clips on and off the base of the pack. So you can have spare batteries charged and ready to swap over if needed. The charger port is in the battery itself, so you can have one battery charging while another is being used with the pack.
Another reason this is important is that Lithium batteries generally have a limited life (of around few years). Many of the alternative power packs have the batteries sealed inside, or even if they are accessible its still not clear if there will be readily available replacements (now, or in a few years time when you will likely need them). So although the PB960 is not the cheapest option, at least you know its not destined for the bin when the battery wears out.