I would do a Google search E.P.M. Battery, and see what comes up. I think Deka is one name, as well as Startrite on my battery.
Speaking of batteries, I had a pleasant shock today when I put my battery charger on a 10 year 1 month old Fleet Farm battery. It showed a 2 amp charge on the meter, so I figured it was good enough to do some wiring and bulb checks in my Studebaker today. I put it in the car, then hit the starter expecting to hear nothing, but the engine spun like new, so it looks like I won't even have to buy a new battery.
Like I said before, I've always had many more years of life from a 6 volt battery than I've had from 12 volt batteries.