The VRK 21700 3750mAh 3.7V Li vape battery 40A  comes as a single unit with a maximum voltage of 4.2V and a continuous discharge of 40A. Choose a hi-drain battery that won't let you or your mod down.

The VRK 21700 Battery Spec:

• Size: 21700
• Nominal Capacity: 3750mAh
• Nominal Voltage: 3.7V
• Maximum Voltage: 4.2V
• Discharge: 25A Max Continuous, Rated 40A Max Pulse
• Positive: Flat
• Protected: NO, UNPROTECTED
• Rechargeable: Yes
• Dimensions: 21.05mm x 70.38mm
• Weight: 88.4g

Additional Help & Advice

It's generally safer to use an external battery charger if you as using a device with 18650 batteries. The reason for this is that you protect against wearing out your micro USB port and most external battery chargers deliver more balanced charge which prolongs the life of the battery and the device.

Always ensure that you never use damaged batteries in either your device or separate charger as battery wrapping protects the device.

If your device uses dual or triple battery configurations make sure you use the same brand of batteries with the same level of charge.

Please be aware that there is always a slight risk when using rechargeable batteries. Make sure batteries are never left charging unattended. Always keep your batteries in a container that is non-conductive to reduced risk. When moving batteries in and out of your device or charger make sure that you always check the batteries for any sign of damage. If they are damaged please do not reuse them.

Batteries (especially rechargables) are required by law to be rcycled. Never burn them, trash them or put them in water. Due to the heavy metals and toxic chemicals they contain, they cause soil contamination and water pollution.