The Eleaf iStick X40 and Innokin Coolfire Z80 Nex sit at different points on the output spectrum, which shapes most of the differences between them. This comparison sticks to the specs and review notes available, and calls out plainly where the data isn’t enough to pick a winner.
Below we break things down by performance, battery, convenience, capacity, and build, using only the figures provided for each device.
| Spec | Eleaf iStick X40 | Innokin Coolfire Z80 Nex |
|---|---|---|
| Image |  |  |
| Max outputPerformance | 40 W | 🏆 80 W |
| Battery typeBattery | removable | Replaceable 18650 |
| Battery capacityBattery | 3000 mAh | Not stated |
| DisplayConvenience | Yes | Yes |
| Charging portBattery | USB-C | USB-C |
| Coil/tank compatibilityCapacity | 0.4Ω, 0.8Ω, and 1.2Ω | Full Z Coil series |
| Vaping stylePerformance | MTL | Not stated |
| Safety protectionsBuild | Usual | Not stated |
| Build materialBuild | lightweight zinc alloy | Zinc alloy, PCTG, leather |
| Best US priceat time of comparison | $49.90* | $45.77* |
| Read Review & Best Price | Read Review & Best Price |
* Lowest US price we found on 18 Aug 2026. Prices change often — see each review below for live pricing.
Performance
The Innokin Coolfire Z80 Nex wins on performance thanks to its 80 W max output, double the Eleaf iStick X40’s 40 W ceiling. That extra headroom generally supports a wider range of coil builds and vapor output, while the iStick X40’s 40 W cap and stated MTL vaping style point it toward a more restricted, tighter-draw experience. The Coolfire Z80 Nex’s vaping style isn’t stated, but the higher wattage alone is enough to settle this category.
Battery
Battery data is too thin to call a winner here. The Eleaf iStick X40 lists a removable 3000 mAh battery, while the Innokin Coolfire Z80 Nex specifies a replaceable 18650 cell without a stated capacity. Both use replaceable batteries, but without a matching capacity figure for the Coolfire Z80 Nex, a direct comparison isn’t possible.
Convenience
Convenience ends in a tie. Both devices include a display and both charge via USB-C, so day-to-day usability on these two fronts is evenly matched based on what’s documented.
Capacity
There isn’t enough evidence to declare a winner for capacity. The spec sheet doesn’t provide tank or juice capacity figures for either the Eleaf iStick X40 or the Innokin Coolfire Z80 Nex, only coil compatibility details, so this category can’t be judged fairly.
Build
Build is inconclusive with the available facts. The Eleaf iStick X40 is built from lightweight zinc alloy, while the Innokin Coolfire Z80 Nex combines zinc alloy, PCTG, and leather. These are different material approaches rather than directly comparable specs, so no winner can be assigned here.
The Eleaf iStick X40 suits vapers who want a straightforward MTL setup at a lower 40 W output with a removable 3000 mAh battery.
The Innokin Coolfire Z80 Nex suits vapers who want more power headroom, with its 80 W max output outpacing the iStick X40.
The verdict
Neither device comes out ahead across the board. The Innokin Coolfire Z80 Nex has a clear edge in performance thanks to its 80 W output, while convenience is a tie thanks to matching displays and USB-C charging on both units. Battery, capacity, and build don’t have enough comparable data to name a winner in either direction, so the choice ultimately comes down to which specific strengths matter most to the buyer.