Before you look at any specs, ask yourself how often you actually reach for your vape. A heavy user who takes five-minute breaks every hour needs a different device than someone who takes a few puffs after dinner.

Here's a rough way to think about it: a 300mAh battery might get you through a light day, maybe 50 to 80 puffs. Bump that to 500mAh and you're looking at 150 to 200 puffs, which covers most moderate users. If you're a chain-vaper, you'll want something in the 700mAh to 1000mAh range, but be ready for a chunkier device.

Your draw style matters too. Long, slow draws drain more battery per puff than quick puffs. Same with temperature: if you're running a device that lets you adjust heat, higher settings eat more power. So don't treat mAh as a magic number—it's a starting point for matching the device to your habits.