I guess lack of batteries must always be an issue in the field.
They transitioned to AA, used to be Li batteries. Couple of helmet and pocket fires later, AA fix was in. Batteries outweigh ammo for long patrols. Radios have to stay up and the battery tech in the 90s lagged. @ squadron level, there are batteries available, but some people don’t plan worst case. Nothing worse than NVGs going out for lack of power.