They are not battle tested so I wouldn't advise to use them in a project like this one, but I'm building LED fresnels that get the same light output as a 500W tungsten fresnel, drawing a bit less than 100W of power. They use CREE CRI 93+ LEDs, and optical-grade glass (it's not a fresnel lens actually, but it does the same function). They weight 500g each (one pound), plus about as much for the adapter, which sits on the ground (I wanted to make the fresnel itself as small and light as possible). They have absolutely no flicker at any frequency I have tested (at least up to 1/2000s). My aim is to sell these at around $400 each.
Two downsides:
They have a slow-moving, almost-silent fan (for me it's no problem at all, but for others it might be).
If you like your gear to be able to withstand rough use, they are not for you: they are made of ABS plastic, and I already broke one in a 1.5m drop test (that's five feet) (it still works but the fan lost one blade and is unbalanced now; I can rapair it easily but for others it wouldn't be so simple).
Why I post this here: currently they need to be plugged, but I could make them work with batteries as well. A $100 LiPo battery that weights one kilo (2 pounds) and needs a $50 charger would keep one working for two hours. But I'd have to work on it to make sure everything is OK. Do you think it would be worth the effort?
Interesting to a degree, no question. Super affordable. However, no matter how affordable, it will miss the boat if it doesn't hit selling points - you'd be better off bumping the price up and hitting selling points. Battery power is the #1 requirement, IMHO. Because there are plenty of varying quality fresnel/par LEDs that are AC powered already, though usually for a lot of $. What most of us want is battery powered LED fresnels. That is a key differentiating requirement. However, it is not the only one. The second one, sadly, is output. It would be great if this pushed out the equivalent of 1K tungsten fresnel, rather than 500W. If you had something like that - battery operated, 1K equivalent, dimmable, flicker-free, around 95 CRI, and sold it for under $800, I think you'd have buyers line up around the block. Also, by battery powered, I don't mean lugging a battery that's the size of a small car and that costs as much. Basically, what the OP needs - the ability to shoot night exteriors with battery powered LEDs.