Hi Linda and Steve, We are having currently 6 x 8D as the house battery, and we are about to upgrade to some more serious batteries. The new batteries will weight approx. 1600 pounds and will not fit in the old spot. The current batteries are about midship and about 1 foot in from starboard (not the best place you would think). We have space right after the engine room, right on the center of the boat. beam-wise we would move only a few feets, but length-wise we would shift a lot of weight (800 pounds) about 15 feet further aft. Now…we are talking about a 35-metric-ton 60-foot boat here, so in my opinion it should not make too much a difference, but I would be really interested in your opinion. Thank you for your help, Thomas
Hi Thomas: Moving the batteries aft is a change in trim of 24,000 foot pounds (15′ times 1600 lbs). You can easily calculate the change in trim (the stern will go down a bit) if you find out the foot pounds required to change your trim one inch. As a wild guess, if this figure was 7,000 foot lbs, the change in trim would be 24,000/7000 or 3.4″ The designer of your hull can calculate this figure for you in a couple of minutes, or you can do it yourself once you have the data. Most cruising boats end up pretty heavy, and tend to trim by the bow, so my guess is that this stern down trim will not be a big problem, and may even things out if you are presently bow down. One way to test this would be to add some sand bags, or a dinghy full of water, to the correct spot on deck and visually look at the water line. – Steve
Posted by Steve Dashew (November 30, 1999)
