I bought a small 30ish bulb LED lamp for various purposes, including AF assist.
It also helps put out light for models doing makeup while shooting in less-than-ideal and dark outdoor places, provide baggage area light for easy (and safer) equipment retrieval, and of most recent - being a spare light for my bbq pit when the lamp actually fused (lol).
I actually use it for anything other than lighting the models for photos itself. I'm just spoiled by the quality of light strobes produce.
Nevertheless, it serves much purpose and takes up minimal bag space. 4 eneloops power it for at least 1 1/2hours before it starts dimming bit by bit, possibly to 3hours.
If you intend to do shoots in complete darkness without a nearby power source nor nearby lighting, LEDs are a true lifesaver. DIY a frosted cap or simply shoot it off at a large-ish white paper or wall and everyone will get some light,