By use case
Best lithium battery for a catamaran
Catamarans carry the largest house loads on this site — two fridges and a freezer, an inverter big enough for induction, and often a watermaker. That combination is what pushes a boat from 12 V to 24 V, because the cable required to move that current at 12 V stops being sensible. It also means the bank is large enough that brand support matters.
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Selection criteria and compatibility
- 24 V cases where the loads justify it, which on most cruising cats they do.
- Capacity for two fridges running continuously in the tropics, not just at anchor in Tasmania.
- Charge acceptance to match a large solar array on the hardtop.
- Support across the cruising grounds you actually use.
The mistake to avoid
Converting to 24 V for the battery alone
Twenty-four volts is the right answer when the loads demand it — an induction hob, a large inverter, long cable runs. It is the wrong answer if you are chasing battery efficiency, because rewiring a whole vessel costs far more than the cable you save.
The picks
Recommended options by application
A marine-positioned 24 V option. Four cases create a 400 Ah 24 V bank with redundancy, subject to the installer's review of the current model evidence.
Where it falls short: The boat is 12 V and staying that way.
Full detailThe documentation an electrician certifies against, and a dealer network that spans the east coast cruising grounds.
Where it falls short: The rest of the boat is 12 V — converting a whole vessel to chase battery efficiency rarely pays.
Full detailPriced below the marine specialists and integrates with its own controllers — provided you accept documentation written for off-grid rather than for AS/NZS 3004.2.
Where it falls short: Marine certification documentation is a requirement.
Full detailIf the boat is 12 V and staying that way, large low-profile cases are the practical answer in a hull locker.
Where it falls short: Redundancy across two cases matters more than a single install.
Full detailBefore you buy
Confirm battery capacity and equipment compatibility
A recommendation is only worth acting on once you know what the boat needs. The calculator works it out from your own loads in about a minute, and everything above reads differently afterwards.