Thanks to "Cthugha" at the Physics Forums for bringing this paper to my attention (this is what happens when one is trying to catch up with work after the holidays - one forgets to troll the various physics journals sites).
A new paper in PRL has a very interesting theoretical calculation for lead-acid battery used in motor vehicles. Supposedly, there are no ab initio calculations for such battery works, i.e. no theoretical calculation for the energies of the reactants - till now!
Abstract: The energies of the solid reactants in the lead-acid battery are calculated ab initio using two different basis sets at nonrelativistic, scalar-relativistic, and fully relativistic levels, and using several exchange-correlation potentials. The average calculated standard voltage is 2.13 V, compared with the experimental value of 2.11 V. All calculations agree in that 1.7–1.8 V of this standard voltage arise from relativistic effects, mainly from PbO2 but also from PbSO4.
But what made it stood out is the end of of the paper, where the authors wrote "Finally, we note that cars start due to relativity"! :)
Well, there ya go! If anyone questions you on the use of relativity, you point to their car batteries!
I love it!
Edit: Don't miss the Physical Review Focus coverage of this work.
 R. Ahuja et al., Phys. Rev. Lett. v.106, p.018301 (2011).