An item with this enchantment effectively acts as if it has an exclusive Powerstone but instead of an actual Powerstone the energy is a battery.
Classic: Technomancer doesn't give a formula for translating Volts or Watts (Volts x Amperage) into FP resulting in confusion as to where the numbers in the conversion table on p. 20 are coming from.
For example, while it explains that the 12-volt cell (which grants 5 fatigue) is a "standard" car battery but it also states that 1 kWs is 0.00277. The problem is car batteries use CCA (cold cranking amps) which means a 700CCA battery will pump out 8,700 (700 x 12) watts for a few second or 23 fatigue nearly five times what it is supposed to provide. back figuring gets a 150CCA 12-volt cell (which do exist). But this problems exist will all the numbers as one is missing a key piece of information to understand the numbers.