A version of this article appears in the January/February 2020 issue of Good Old Boat Magazine.
Batteries are heavy. In a sailboat they are best positioned low and near the centerline of the boat and in a battery box. In other words, in some not easily accessible space. Most batteries destined for the marine market have handles or straps on them so they can be easily, well sort of easily, removed and replaced.
Many sailors have opted for batteries not specifically targeted for the marine market. Second Star and other sailboats destined for a cruising life often use 6v golf cart batteries. Wired in a series parallel circuit, GC batteries provide more electrical power for the money than standard Group 27 or 31 batteries. Designed for the demands of electric golf carts, GC batteries do not have straps or handles, rather the case has two ears to which a lifting strap is attached. The strap, made of thick rubber with steel hooks on each end, quickly connects to the ears allowing the battery to be lifted. The straps are inexpensive, readily available on Amazon.com, and most important, they work; except they come with an expiration date.
As the straps age, they become softer, more elastic, and weaker. A poor combination when lifting a 65-pound battery from deep within the boat. Suspended on a now elastic strap, the battery bounces as if hanging from a rubber band. If the strap breaks while hoisting a battery damage to the boat or a body part might well result.
Tossing an aging strap in the trash and buying a new one every couple of years is the easy solution. True they are cheap enough, however throwing them out adds to a growing trash problem and is antithetical to a frugal sailor. A better solution would modify the strap to safely extend its life.
Design requirements for the strap are simple, it must be strong enough to lift the battery’s weight and fat enough to be relatively comfortable. A thin piece of dynema line would be many times stronger than needed, however it would be far from comfortable when lifting a 65-pound battery. A second consideration is the strength of the hooks. The material must be strong enough to resist bending under the battery’s weight.
Being frugal means the best solution will be inexpensive and functional. The hooks and brackets could be reused if a suitable attachment method could be developed. After considering several options, that tubular nylon webbing emerged as a viable option. The webbing was strong enough to support the load, inexpensive, and readily available; it met all the criteria. A plan developed: remove the bracket and hooks, insert the rubber strap into the tubular webbing, and secure the brackets and hooks with machine screws. The webbing would support the weight and the rubber strap would provide a comfortable grip.
Constructing the Better Battery Lifter
Begin by deconstructing a lifting strap. The hooks are attached to the strap with one or two rivets. Grind the heads off the rivets using a bench grinder or similar device and punch out the rivets. Remove the hooks from the strap and discard the old rivets.
Next trim the rubber strap to fit inside the tubular nylon webbing. I used one-inch webbing which was a little too small for the rubber strap, wider webbing would eliminate trimming the strap. Insert the rubber strap into the webbing and locate the rivet holes in the strap. Using an awl or nail, pierce the nylon webbing to open the holes. Slide the small bracket with the hooks onto the strap.
The holes were enlarged, and the edges melted using a red-hot nail. A suitably sized nail locked in a vice was heated with a propane torch. Piercing the strap, the nail enlarged the hole and sealed the threads. Finally, the hooks were attached with ¾” 10-24 SS machine screws and nyloc nuts.
Aboard Second Star the lifting strap was put to the test. Reaching down into the battery box, the strap was attached to a battery. The hooks engaged with the lifting ears and the battery came up and out of the box. The strap felt secure and comfortable, without stretching or a rubber band effect. The lifting strap, now in a stylish blue nylon cover, worked as expected.