Ampere hour (mAh): Understanding the battery capacity of e-cigarettes

The ampere-hour is a unit of measurement for the amount of electrical charge that a battery can store. 1 ampere-hour (Ah) is equal to 1000 milliampere-hours (mAh). Theoretically, 1000 mAh means: the battery can supply 1 ampere of current for one hour – or 0.5 amperes for two hours, or 2 amperes for half an hour.

In practice, mAh is a measure of capacity, not power. To calculate the actual amount of energy (in watt-hours, Wh), you need to factor in the voltage: a 3000 mAh battery with a nominal voltage of 3.7 V stores around 11.1 Wh. Two batteries with the same mAh rating but different voltages therefore deliver different amounts of energy.

This is to be distinguished from the maximum discharge current (in amperes, A), which indicates how much current a battery can deliver at any one time. For sub-ohm vaping, this value is often more important than the battery capacity alone.

The required battery capacity (mAh) depends heavily on the type of device and your vaping habits. As a rough guide for everyday use in Switzerland:

Disposable vapes and small pods

Disposable e-cigarettes usually have a built-in capacity of 400 to 650 mAh and are designed for a specific number of puffs. Pod systems such as refillable pods range from 500 to 1500 mAh – enough for half a day to a full day with moderate use.

Battery mods and mods

Simple stick-style battery mods deliver 1500 to 2500 mAh with an integrated battery. Box mods with a single 18650 battery typically reach 3000 mAh, whilst dual-battery mods, using two 18650s, combine to deliver around 6000 mAh. For sub-ohm vaping at 60 to 80 watts, a dual-battery setup is often advisable, as single cells quickly reach their current limit in such scenarios.

Rule of thumb for runtime

A 3000 mAh battery at 3.7 V stores 11.1 Wh. If you vape constantly at 50 W, that works out to around 13 minutes of continuous vaping – in everyday use, depending on the length of each puff, that’s a good 300 to 500 puffs.

A high mAh rating isn’t automatically the better choice. These points will help you compare:

• Check the discharge current: For sub-ohm coils below 0.5 ohms, you need batteries with a continuous discharge current of at least 20 A. A cell with a high mAh rating but low current capacity can become overloaded in this scenario.
• Take device efficiency into account: Two pod systems, each with 1500 mAh, may last for different lengths of time because coil resistance and chip efficiency vary.
• Integrated vs. replaceable battery: Built-in batteries are more compact, but become noticeably weaker after 300 to 500 charge cycles. 18650, 20700 or 21700 cells can be easily replaced.
• Cell quality: Look for branded batteries from manufacturers such as Samsung, Sony/Murata, Molicel or LG. No-name cells claiming 5000 mAh in the 18650 format are dubious – physically, the upper limit is around 3500 mAh.
• Choose the right charger: An external charger with adjustable charging current (0.5 A for gentle charging, 1 A for everyday use) significantly extends the lifespan of your batteries.

Does a higher mAh rating always mean longer runtime?

Not necessarily. More milliampere-hours mean more stored charge, but the actual runtime depends on wattage, coil resistance and draw duration. A 2000 mAh pod at 15 W often lasts longer than a 3000 mAh mod at 80 W.

Can I trust the manufacturer’s specifications for the mAh e-cigarette?

With established brands, usually yes. Caution is advised with very cheap no-name batteries: specifications of 5000 or 9900 mAh in the 18650 format are technically impossible. A maximum of around 3500 mAh is considered realistic.

How long does an mAh battery last over its lifetime?

Lithium-ion cells lose a little capacity with every charging cycle. After 300 to 500 full cycles, you’ll typically still be at 70 to 80 per cent of the original battery capacity. Gentle charging extends the service life.

Is 1500 mAh enough for a vape?

For moderate users with an MTL pod system (mouth-to-lung, low wattage), 1500 mAh is often enough for a whole day. Sub-ohm vapers with high consumption should opt for 2500 mAh or more – or carry a spare battery.

The ampere-hour is a useful metric, but only one component in the interplay of voltage, discharge current and device efficiency. Choosing a battery capacity based on your vaping profile – MTL or sub-ohm, occasional or intensive – helps you avoid running out of power at the wrong time and saves you money in the long run. Take a look at our range of chargers and battery accessories, compare capacities and make sure you choose the right cells for your setup. You’ll also find suitable mod bodies in our range.