[Johnny1A.2]

The thing to remember about a Smithian accumulator is that it isn't a capacitor or a battery. It's a totally different technology, probably based on physics we don't understand, like a lot of the rest of their tech.

An accumulator is defined not by how it works, but by what it does, i.e. store large amounts of energy with the ability to release it very fast. How it does it matters less than what it does.

How much energy does a Smithian accumulator store? He never gives hard figures, but lower bounds can be estimated by observing what the technology does. The answer is 'a freakin' lot'. They can power hand weaponry with more than enough juice to vaporize large masses like humans, or sections of walls. (It takes far more energy to vaporize a human than it does to kill one.)

The shipboard accumulators can store significant amounts of energy relative to their total-conversion based power plants.

Remember the old Star Trek TOS trope of the phase pistol set to turn into a bomb? There were a couple of incidents where it was shown that this could be done, and Kirk says at one point (paraphrasing) that such a pistol bomb could have blown the side of the ship out if they hadn't stopped it.

That's completely realistic, given the displayed performance of the phaser pistols (rapid vaporization of large masses, etc.). That much energy packed into a small space will make a dandy bomb if it gets released instantly.

The Smithian accumulators have similar storage densities, or higher.