Of course, it does get messy if one takes the power consumption rates into
account. Has anyone tried to simulate NiCad batteries with the rules?
(I vaguely suspect that's what the rules calibrated against.) And then
there's the possibility to batteries that can be fast-charged (for increased
cost).
Of course, the latest battery technology appears to be able to make electric
cars viable for urban use. (A friend of mine pointed me to a magazine with
the relevant article. If there's interest, I could hunt it down.) Part of
technological cost is developing the infrastructure for a technology, but
that shouldn't be part of the cost in Traveller, since it is perhaps safe
to assume that technology is reasonably stable. Or one could charge extra
for "new" technology on a given planet.