Vaping Batteries | How Are They Made?

Jun 22, 2022Updated Sep 17, 20266 min readVape School

Lithium-ion batteries power almost everything you carry, from your phone to your laptop. In a vape, they do the heavy lifting: every time you press the fire button or take a draw, a small cell sends a burst of current to your coil.

So where do those cells come from, and why does it matter which ones you buy? This guide follows a vaping battery from raw lithium to the store shelf and explains what that journey means for you.

What is inside a vaping battery

Most mods use removable cylindrical cells named for their size. An 18650 is 18 mm wide and 65 mm long, and a 21700 is 21 mm by 70 mm. Pod systems and disposables use a built-in battery instead, but the basic chemistry is the same.

Every lithium-ion cell has four main parts:

• Cathode (positive electrode): a lithium metal oxide coated onto thin aluminum foil.
• Anode (negative electrode): usually graphite coated onto thin copper foil.
• Separator: a very thin, porous plastic film that keeps the two electrodes apart while letting lithium ions pass through.
• Electrolyte: a liquid containing a lithium salt that carries those ions between the electrodes.

When you fire your device, lithium ions travel through the electrolyte from the anode to the cathode, while electrons flow the long way around, through your coil. That flow of electrons is what heats the coil. Charging pushes the ions back the other way, ready for your next session.

Vaping cells are usually INR or IMR types. Those codes point to a nickel-based or manganese-based cathode chemistry, the kinds used in high-drain cells that can deliver the current vaping demands.

Step one: getting the lithium

Lithium is a soft, very light metal that is too reactive to be found pure in nature. Most of the world’s supply comes from two kinds of sources: hard-rock mines, especially in Australia, and salty underground brines beneath the salt flats of South America. In the United States, lithium has long been produced from underground brine in Nevada’s Clayton Valley.

Brine operations pump the salty water to the surface and spread it across large evaporation ponds. The sun does most of the work, slowly concentrating the lithium over many months. The concentrated brine then goes to a processing plant, where soda ash is added so that lithium carbonate settles out. After purifying and drying, what is left is a fine white powder, one of the key starting materials for battery cathodes.

Step two: building the cell

Cell factories turn those raw materials into finished batteries through a series of tightly controlled steps:

1. Mixing. The active materials are blended with binders and solvents into a thick paste called slurry, one batch for the cathode and one for the anode.
2. Coating. The slurries are spread in thin, even layers onto long rolls of aluminum foil for the cathode and copper foil for the anode, then dried.
3. Pressing and cutting. Rollers press the coated foil to an exact thickness, and it is cut into long strips.
4. Winding. For a cylindrical cell, the cathode, separator and anode strips are rolled together into a tight spiral, often called a jelly roll.
5. Canning and filling. The roll goes into a steel can, tabs are welded to connect it to the terminals, and the can is filled with electrolyte in a very dry room, because moisture reacts with the electrolyte.
6. Sealing. A cap goes on top. It typically includes a safety vent that lets gas escape if pressure builds up inside.
7. Formation and aging. Each new cell is charged and discharged for the first time under careful control, then stored for a while so weak cells can be spotted.

Cleanliness matters at every stage. A stray metal particle inside a cell can damage the separator and cause an internal short circuit, which can make the cell overheat. That is why well-run factories rely on clean, dry production areas and strict quality checks, and it is one reason cheap cells from unknown factories are a gamble.

Step three: testing, grading and the trip to your vape shop

Finished cells are tested for capacity, voltage and internal resistance, then sorted by how they measure up. Major cell makers such as Samsung, LG, Sony (whose battery business now belongs to Murata) and Molicel design many of their cells for manufacturers of products like power tools and laptops.

Cells reach vape shops through distributors and wholesalers rather than straight from the factory. Along the way, some brands buy cells made elsewhere and sell them under their own wrap, and the ratings printed on those wraps are not always accurate. Counterfeit cells made to look like popular models are a real problem too.

That long chain is why independent testing matters. Battery testers in the vaping community, such as Mooch, publish their own measurements of what popular cells can really deliver, and those results are worth checking before you buy. For a deeper dive into battery chemistry, the free educational site Battery University is a good place to start.

What this means when you buy batteries

• Buy from reputable sellers. An established vape shop or battery specialist is far less likely to sell you a fake.
• Trust the continuous rating, not the wrap. The continuous discharge rating (CDR), in amps, is the number that matters for vaping. Compare it with the cell maker’s specifications and independent tests.
• Match the battery to your device. Use the size your mod’s manual calls for, and in dual-battery mods, use matched cells of the same model and age that are charged and used together.
• Inspect the wraps. On a typical cylindrical cell, the whole metal can is the negative terminal, and the thin plastic wrap is its insulation. Rewrap or replace any cell with a torn wrap or missing insulator ring.
• Carry and charge with care. Keep spare cells in a plastic case, never loose with keys or coins, and never leave batteries charging unattended.

For specific cells and their specs, see our list of recommended batteries for vaping. For charging, read the best vaping battery chargers, and if you use a mechanical mod, our mechanical mod battery safety guide is essential reading.

Common questions

WARNING: This product contains nicotine. Nicotine is an addictive chemical. For adults 21+ only.