Description

Choosing the Right Battery for your Vape

The 25 amps is suitable for most uses, with high enough drain and a good battery life at 2000 mAh.

In more detail

Unregulated

In an unregulated device, ie one without wattage control, the battery drain depends on the resistance of your coil.

Coil resistance	Battery Amps
0.4 ohms+	20A
0.3ohm-0.2ohm	25A
0.15ohms and less	30A

Regulated

In a regulated device, eg VW where you set the wattage, the amp draw depends on the wattage you set and the remaining battery voltage. Assuming good quality batteries like LG or Sony and a vape with a low end voltage of 3.4V, a 20A battery is good for about 60W per battery; a single 25A about 75W per battery and a single 30A battery you are good up to 90W; with a pair of batteries in a dual battery vape you can double that.  

	Single Battery	Dual Battery
20A	up to 60W	up to 120W
25A	up to 75W	up to 150W
30A	up to 90W	up to 180W

 

The Maths (Ohm's Law)

 

The wattage is generated by the vape or mod by multiplying the volts by the amps. As the voltage falls, the mod will increase the amp draw to maintain the selected wattage from the remaining voltage level.

You need to know the amp draw at full charge (4.2), and when the battery is discharged (3.4) as this value will be the highest. Most regulated mods are about 90% efficient, so you will also need to factor this loss into your calculations as it will increase the amount of amperage pulled from the battery.

Amp draw I = P/V (-10%)

Eg.

50W/ 4.2V = 11.9 divided by 0.9 = 13.22 amps

50W / 3.2V = 15.6 divided by 0.9 = 17.33 amps

Or available wattage is P = IV x 0.9

25A x 4.2V x 0.9 = 94.5W

25A x 3.4V x 0.9 = 76.5W

Here is a useful tool for understanding Ohms Law from Steam Engine