Thanks to an ongoing tangible reduction in prices, the life cycle costs of lithium boat batteries are now close to those of conventional options. Upgrading an existing boat to the newer technology is therefore increasingly feasible.
Larger new cruising yachts, especially those at the quality end of the market, have been routinely fitted with lithium boat batteries for the past few years. Arcona, for instance, says up to 90% of their larger yachts now leave the factory equipped with them. Equally, the technology is increasingly embraced in the racing world, whether at the top end on IMOCA 60s and 40s or smaller IRC yachts competing in RORC’s offshore races.
Benefits include a considerable reduction in physical size and weight and a radically increased number of charge-discharge cycles. Typically the best lithium boat batteries will withstand four or five times the number of cycles compared to most deep cycling lead-acid batteries.
This is a significant factor in reducing their long-term costs. However, it has to be remembered savings will often not be realized until five years after installation, when conventional boat batteries may be nearing the end of their lifespan. As prices of lithium-ion relative to capacity continue to fall, total life cycle costs are likely to drop below those of lead-acid batteries.
However, a lithium boat battery is not a straightforward drop-in replacement for lead-acid batteries. Instead, a comprehensive and unified upgrade of boat battery management systems and regulation for all charging sources is needed to eliminate the possibility of thermal runaway, creating a self-sustaining fire.
Despite the improving economic case for lithium boat batteries, this is rarely the prime driving force behind owners’ motivation. Entirely simply, they are better suited to today’s increasingly complex and power-hungry yachts. Lithium boat batteries can even make it possible to run air conditioning through the night without resorting to the disruption of a generator.
Equally, a lithium-based system may store enough power to make it feasible to change from gas to electric induction cooking and from a petrol tender to an electrically powered one.