When Vittoria Vetra is explaining to Robert Langdon how the antimatter containment canisters work, she explains that the built-in battery needs a special charger geared to the specific location. Among the components she mentions that the chargers contain, are servo-coils.

Now as any fairly technically-literate person knows, a servo-coil is that part of a hard disk drive (or CD/DVD/BluRay etc. drive) which moves the heads in and out. What on earth would such a component be doing in a battery charger?