Fenix ARB-L18-4000 Rechargeable Battery

The 4000mAh rating is no joke—my light runs noticeably longer between charges compared to my old 3000s. That 7A stable output also keeps the beam steady even when I'm pushing the light hard.

I was a bit worried the higher capacity would mean more heat, but the thermal performance really holds up even during longer pulls. The 4000mAh has easily doubled my time between charges compared to my old cells, and the stable 7A output keeps my light running strong without any hiccups.

Ran the light for three straight nights of camping and it still showed a full bar when I got home. The 7A stable output kept the beam from flickering even on turbo mode.