Yes...and no
I have the same problem...the leak is on the starboard side, but the battery box on my '78 is on the port side. Anyhow, so far I have eliminated all deck fittings leaking (my boat is docked by my house, so I can go out there when it is actually raining) as there are no drips from the nuts. I taped the windows to make sure they were not leaking. That wasn't it either. I sprayed the cockpit lockers heavily and they didn't let in a drop. I've religiously checked the drain tubes and volcano tube...every thing is nice, tight and dry. And my boat has a cover over the entire cabin up to the mast and extending three feet into the cockpit, so it is not the cabin top or the hatch or hatch boards. The only thing left that I can think of is that water is running along the rub rail and getting behind it and then finding a way in thru the join of the hull and deck. I will be running water on the rub rail soon (as in, whenever the weather cools off or we get some decent cloud cover) and if that's not it, I don't know where to go next.Anyhow, that's at least a partial list of things that can leak and might put water in the battery box area. If you can't go to your boat when it is raining to check and see if you can actually observe water coming in, you can mark suspect areas with a colored waterbase pen...and it will run (smear) if any water flows across it.Considering where your water is ending up, I'd guess the most likely leak possibilities are 1) hose from the scupper drain, 2) thru the hatch boards, or 3) any holes on the cabin roof where the sealant/bedding may have failed. And then there is the rub rail.Good luck in your search.