Ok, I'm starting to put some ideas together and I need some advice from all you battery and electrical geniuses.

Ok, so I won me some Hella Marine lights that use 12v 37.5 watt bulbs. I'll only be running one of them. My commute is about 2.5~3.0 hours round trip. According to the math I'd need a battery with 7+Ah to make the trip w/o having to charge at the office. I was looking at the option of ten 1.2 volt D-Cell 9500mAh NiMh batteries (like these) in series. That'd meet my power and run time requirements perfectly. My questions are....how do you charge such a beast? And how long would it take?

edit: Or I guess I could also use ten 1.2v 4500mAh NiMh C-Cells in series+parallel to get 12v w/ 9000mAh; but the questions are still the same.