/diy/ - Do It Yourself

Looking for advice on a good high power lamp.
I like going out in the fields / woods at night and looking at the wildlife so want a fairly high power light.
I've been getting a few of the cheap CREE knockoff flashlights like pic related and although they're decently bright, the batteries last like 10 minutes.
I've tried modifying a few to plug into my 10000mAh USB power bank and they work for a while but eventually burn out (I think there's a shitty PWM circuit in them that goes bad and causes the lamp to flash eratically)

I've been thinking about maybe making something myself but wanted some advice.
I'd like something that I could recharge (Are sealed lead acid batteries a good idea?)
I'd be using a fairly high power COB so I'd need to step up to 36 or 52V.
Ideally I'd want to be able to just use conduction to keep the COB cool.

Or if anyone would could recommend a decent off the shelf light that can hold a charge for an hour or two.