Which Battery Do I Need for My Mod?Updated 15 days ago

Step 1 — Find Your Battery Size

The battery size required by your mod is usually printed on the device or in the manual. Common sizes:

18650: The most common vape battery size. 18mm diameter, 65mm long. Used in the vast majority of single and dual battery mods.
21700: Slightly larger than 18650. Offers more capacity (longer battery life) and higher drain capability. Increasingly popular in newer mods.
20700: Between 18650 and 21700 in size. Less common but used in some devices.
26650: Large format battery. Used in some high-power mods.

Step 2 — Check the Continuous Discharge Rating (CDR)

The CDR (or continuous discharge rating) tells you how many amps a battery can safely deliver continuously. This must be equal to or greater than the amperage your mod draws at maximum wattage.

To calculate required CDR: Amps = Watts ÷ Voltage. At 4.2V (full charge): a 100W mod needs approximately 24A CDR. Choose a battery rated at 25A or higher.

Our Efest, Imren, and Blackcell batteries are all rated with accurate CDR specifications for vaping use.

Step 3 — Choose a Quality Brand

Not all batteries are created equal. Many cheap or unbranded batteries have inflated capacity and CDR claims. We carry:

Efest: Long-established vape battery brand. Reliable, well-rated, available in 18650 and 21700.
Imren: High-drain cells with accurate ratings. Popular in the vaping community.
Blackcell: Premium high-drain cells. Excellent performance at higher wattages.

Matching Batteries in Dual Battery Mods

If your mod uses two batteries, always use a matched pair — same brand, model, and ideally purchased together and used together from new. Using unmatched batteries in a dual mod can cause uneven discharge and reduced safety.

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