Battery life comparisons

With the varying amount of battery configurations it's often asked how they compare in terms of battery life.
For example single cell, dual cell parallel, dual cell series and now the 3-cell lipos that will be common in the DNA200.

The way to compare would be by using a simple calculation;
milliampere-hours (mAh) × volts (V) / 1000 = watt-hours (Wh)

• A mod using a single Samsung 25R (2500mAh) cell would produce 9.25Wh
• 2500 x 3.7 / 1000 = 9.25Wh

• A mod using dual Samsung 25R cells configured in parallel would produce 18.5Wh
• 5000 x 3.7 / 1000 = 18.5Wh
• Capacity is doubled when configured in parallel (if same batteries)

• A mod using dual Samsung 25R cells configured in series would produce 18.5Wh
• 2500 x 7.4 / 1000 = 18.5Wh
• Voltage is doubled when configured in series (if same batteries)

Now, in the case of the VS DNA 200 which apparently uses a 3-cell 900mAh lipo

• 900 x 11.1 / 1000 = 9.99Wh

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Take into consideration that a parallel configuration will halve the Amp draw for each battery (15A / 2 = 7.5A). This is not the case for a series configuration.

Parallel is undoubtedly the most convenient configuration for vaping unless you want high power.
That being said I know of at least 2 100w box mods that are configured in parallel.
The Vapor Flask SX and the iStick 100w.