Joann,
We have a rule on the boat that only one light can be on at a time.
That way we don't walk from the front to the back turning lights on and
leaving them on, at least some of us don't.
the idea is that we use a light for a purpose and immediately turn it
off. Through judicial use that way and using oil lamps, we can go for five
to six days using only our deep cycle group 27 house battery, saving the
engine battery for getting under way.
You might consider that kind of discipline with your halogen lights
(some of ours are halogen too) and I'll bet you'll be just fine for several
days at a time.
Glyn