Lithium Boat Batteries: Jes' Swap 'Em In and You’re Done ... Not!
HERE'S A LOOK AT THE ABYC E-13 STANDARD AND SOME CURRENT SALE PRICING THAT MAKES LITHIUM-IRON BATTERIES AN ATTRACTIVE ALTERNATIVE
Some yachtsmen and boatbuilders love ‘em, others hate ‘em. In most instances, however, the debate between proponents and opponents is rife with myths and misunderstanding.
There is no arguing with the fact that contemporary LiFePO4 (Lithium Iron Phosphate) batteries are relatively safe, high-performing, and durable in deep-cycling applications.
Unfortunately, they commonly come with a first-cost 3 to 5 times greater than even high quality AGM (absorbed glass mat) lead-acid batteries.
And they require a different charging profile, which often means changing out your battery charger.
Still, they are reputed to last 10 to 15 times as long. They can accept a high rate of change and, unlike lead-acid batteries, deliver usable voltage until they are run nearly flat — which means, roughly that a LiFePO4 battery rated at 75 amp-hours capacity delivers as much useful power as an AGM battery rated at 100 amp-hours.
All of which significantly complicates the decision whether to go with new-generation LiFePO4 or traditional lead-acid batteries.
For an overview of the relevant issues, see:
The latest published ABYC standard E-13 includes five key components of proper installation:
Installation basics
Charging systems
Battery management systems
Overcurrent protection
Temperature management
Here’s how the standard stacks up:
The bottom line is that LiFePO4 batteries are significantly lighter per amp-hour delivered. (The result of their lighter construction multiplied by their ability to deliver usable voltage during a significantly greater portion of their discharge cycle, about 80% compared to 50% for AGM lead/acid batteries.)
Consequently, with LiFePO4 you pack more power into the same space. Or you can reduce the amount of space taken up by a given amount of battery power.
Thinking of renewing or changing out your batteries or battery bank? Get out your note pad and calculator to determine what you’ll need. Then check out all of the currently available sizes and current sale pricing.
— Fair winds and safe harbors
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