New Battery Box

Batteries are heavy.  An improperly secured battery can become a dangerous missile in a seaway, or Heaven forbid, a rollover.  Rick over on s/v Cay of Sea knows this...

Sometimes I think I should rename this blog “stupid ways I’ve cut plywood” or “How to Make Sawdust.”  It often takes me one complete failure in order to understand how to do a project.  I amaze myself.

Anyway, I built a really nice plywood battery box for my new (to me) batteries.  My boat neighbor was gifted a couple of gel batteries last year, and he in turn gave me his not-very-old group 29 Interstate deep-cycle batteries (two of them).  It was a timely gift, because I was planning to buy a new set of batteries in very short order, and to build a new box for them.  I currently have group 24 batteries – unaltered since I bought the boat 10.5 years ago – sitting loose in plastic boxes with the covers held on by a shock cord. These aren’t the original batteries – the way they are installed is original. I’ve never liked it, but didn’t change because. . . um, I just didn’t. Now that it looks like we might take longer, more adventurous trips, it seems important that the batteries are installed properly. To that end, I built this box:

No, it is not marine ply.  I don’t have a truck with which to haul a full sheet of plywood, and I don’t want to pay $95 a sheet for it anyway.  I’ll epoxy and glass this box, and it will be fine.  Well, not this box.  You see, it’s too small.  Group 29s won’t fit in there, even though I measured carefully.  How did this happen, you ask?  Well, never mind.  Suffice it to say, that I was under the impression that the box had to be sized just so, and I indulged in a folly of false economy.  But it’s a nice box.  For something. . .

I bought more plywood this morning (Home Depot sells 2×4 pieces and they fit in the back of my car), cut it correctly (this time – numerous mistakes on the first box), and put it together this morning.  By lunch time, I was letting the glue cure.

Pile of pieces.

I also decided to just make the box square – simplifies the carpentry a good bit. The larger box on the left is the one I built today.

Later in the day I rounded off all the corners in preparation for glass/epoxy.

I’ll glass the box inside and out in the near future, install studs along the top edge to secure the top (with wing nuts), cut out wire relief slots, and it will be ready to install.  It will be bolted to two adjacent bulkheads in the starboard cockpit locker, painted Bilgecoat-grey, and filled with batteries.

[I like the attention to detail: Rounding the corners is a critical step to get the fiberglass cloth to lay tightly around them. -Ed.]