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Battery Blasphemy?

A contrarian take on battery replacement


All batteries have terminals and cable connectors that need to be periodically cleaned, preferably with a battery brush.

I’m guessing I’m in the same boat as a few other folks these days. I’ve got three marine batteries salted away aboard my trawler Betty Jane, and they’re all pretty old. Truth to tell, I can only approximate their vintage. I’ve owned Betty, along with her three 4D deep-cycle gel-cells (so-called because the acid in them has been transformed into electrolytic Jell-O via the addition of silica gel), for almost five years now, and I’d guess that her previous owner probably replaced all three about a year before he sold her to me. So, doing the math makes my three gel-cells at least six years old, a miraculous bit of longevity, but also an augury of a treasury drain facing me in the near future.

Of course, replacing any boat’s batteries—and maybe upgrading them simultaneously—is not likely to cost as much as a bottom job or an engine rebuild. But opting for state-of-the-art gel or Absorbed Glass Mat (AGM) technology (which uses boron-silicate mats between the battery’s metal plates to absorb and contain electrolyte) will still entail a healthy chunk of change. Just recently, for example, a Miami-based wholesaler offered me three brand-new 4D Lifeline AGMs for a total of $1,766.85 ($588.95 apiece), a figure that does not include a $100-per-battery shipping fee.

And hey, AGMs and gels don’t even top the technological totem pole anymore. Late last year, at the IBEX boatbuilders’ show in Miami, the Dutch electronics firm Master-volt introduced a lithium-ion battery it billed as “the ideal replacement.” Its claims for the 24-volt units (12-volt models are reportedly in the works) ran the gamut from radically shorter charge times to life spans tripling those of typical lead-acid batteries. The pricetag of $7,600 apiece however, presents a bit of a problem for me. And so does wariness arising from incidents over the past few years in which lithium-ion energized cellphones and laptops overheated, caught fire, and/or blew up.

Luckily less-expensive options abound. Comparatively inexpensive gel-cells still offer more longevity than most other types of batteries, although they tend to require slow charging at low voltages and are prone to charge-related damage. And comparatively inexpensive AGMs still offer virtual immunity from freezing, relatively inexpensive shipping rates (because mat-trapped electrolyte is not considered a hazardous material), recombinant charging (where oxygen and hydrogen recombine inside the battery, thus reducing hydrogen outgassing), and an exceptionally low self-discharge rate. But what about the cheapest product on the shelf these days—the humble, flooded, lead-acid battery?

Consider my trawler Betty Jane for a moment—a slow-mover with little in the way of weight concerns and cold-cranking requirements, easy access for battery maintenance, and an engine room large (and well-ventilated) enough to obviate worries about the outgassing of hydrogen. Dealers for East Penn, a reputable and representative marine-battery manufacturer (they supply West Marine and others) told me they’d supply Betty with a set of flooded 4Ds for less than half the price of AGMs and about a third of the cost of gel-cells.

My take? Sure, the flooded battery may be seemingly antiquated and a tad troublesome in terms of maintenance, but will the others outlast it by a factor of two or even three, particularly when battery longevity’s contingent on battery-charger quality, ambient temperatures, particulars of usage, and the wiles of good ol’ Capt. Murphy? I don’t think so.

All this sounds blasphemous, I know. But when it comes time for me to replace my old gel-cells, I’m actually considering a downgrade—not an upgrade—to old-fashioned technology.

This article originally appeared in the April 2010 issue of Power & Motoryacht magazine.