Do you have a link for that light, please?
It’s very unusual for a pocket flashlight to sustain 3200lm for 1h 30m. The vast majority of lights like that step down after a few minutes.
As a guide, a 1×18650 light will normally be able to sustain 1000lm for a maximum of 1 hour, assuming it’s been built to get rid of the heat without stepping down or becoming too hot to hold. That’s a fundamental limitation of current technology, so there’s no way round it.