To keep that amount of battery power you must be running at 1kt submerged. The results of this will be less targets. Certainly, it will mean less range you can travel overall in the game regardless of what formula you try to use.
Your going to cover more ground using less fuel on the surface. You'll also have more chances to find target using radar, visuals, than passive sonar alone.
Not to mention, you may find yourself in a position that even if you do surface, you'll not be able to get in attack position soon enough for fast TF's.
Patch up that bath plug and rise to the surface. Results that matter are number of ships sunk and I bet a skilled surface runner will outscore a bottom dwelling catfish anyday.
I remember O'Kane about to lose his mind aboard the Wahoo with his first skipper who refused to surface to get in attack positions. This Skipper stuck in WW1 tactics almost broke down several times, refusing to attack, afraid of death...........