How to compare vape device specs without getting confused

Manufacturer spec sheets pack a lot of numbers into a small space, and it is easy to skim past the ones that actually matter for how a device feels to use day to day. This guide breaks down the handful of specs worth checking properly before buying, whether you are looking at a pod kit or a sub-ohm kit, and what each figure practically means.

Wattage range

Wattage range tells you the minimum and maximum power the chipset can push through a coil. A device listed at “5–80W” can run a low-power MTL coil near the bottom of that range and a higher-drain DTL coil nearer the top. What matters is whether the range comfortably covers the resistance of the coils you actually intend to use; a mismatch (very low resistance on a low-wattage device, or vice versa) generally gives a poor or inconsistent vape.

Resistance range supported

Listed separately from wattage, this is the coil resistance (measured in ohms) the chipset is rated to fire safely, for example “0.15–3.0 ohm”. Fitting a coil outside that stated range is generally not recommended by manufacturers, even if it physically screws in, because the chipset’s protection circuitry is calibrated for the listed window. This figure matters most if you plan to switch between coil types on the same device.

Battery capacity and what mAh means for you

Capacity is given in milliamp-hours (mAh): a bigger number generally means more charge stored, though real-world time between charges also depends heavily on wattage used, how often you vape, and screen/chipset overhead. A 2000mAh internal battery run at low pod-kit wattage can comfortably outlast a 3000mAh cell pushed hard in a high-wattage sub-ohm setup. Treat mAh as a rough guide rather than a precise runtime promise, since manufacturers rarely test under identical conditions to each other.

For devices using removable cells, the mAh rating sits on the battery itself rather than the device, and you can generally swap in a higher-capacity cell of the correct size and discharge rating if the device supports it. Our battery and charging safety guide covers what to check before doing that.

Chipset and screen features

Beyond raw wattage, chipsets vary in the features they expose:

• Temperature control (TC) – limits coil temperature when used with compatible wire types (commonly nickel, titanium or stainless steel), intended to reduce dry hits rather than change flavour on standard kanthal coils.
• Puff counter – a running tally of puffs taken, useful for tracking usage patterns but not a substitute for checking e-liquid level.
• Preheat/curve settings – briefly spikes power at the start of a draw before settling to the set wattage, found mainly on higher-end sub-ohm chipsets.
• Screen type – ranges from a simple LED indicator to a full colour display showing wattage, resistance, battery percentage and puff count simultaneously.

Pod and tank capacity

In the UK, refillable pod cartridges and pre-filled cartridges are limited to 2ml of e-liquid capacity, and bottled nicotine-containing e-liquid is sold in bottles no larger than 10ml, under the Tobacco and Related Products Regulations (TRPR). Nicotine strength is capped at 20mg/ml. These limits apply regardless of what a device’s tank physically could hold, so a spec sheet listing a larger capacity for a non-UK market version is not what you will find on a UK-compliant retail model. You can check current rules on GOV.UK.

Coil compatibility

Coil compatibility is brand and sometimes model specific. Two tanks that look similar can use entirely different coil fitting threads or connector shapes. Before buying spare coils, check that the coil series is explicitly listed as compatible with your tank or pod model, rather than assuming a “universal fit” claim applies to your exact device.

Quick reference: what to check before buying

None of these figures tell the whole story on their own. Reading them together, against how and what you actually vape, is what turns a spec sheet from marketing copy into a genuinely useful buying tool.