Marine & RV Battery Packs | Lithium House Banks & Leisure Power

Marine conditions are the hardest in the range

A marine battery compartment is damp, salt-laden, poorly ventilated and often hot. The pack is charged from shore power, from an alternator with a variable output, and sometimes from a generator, and it may sit unused for months at a time.

Each of those conditions has a specific design consequence: sealing that resists salt rather than only water, charge management that copes with varying sources, thermal design that works in a confined space, and a storage regime the owner can actually follow.

RV and campervan: the same problem in a drier form

RV installations are less aggressive on corrosion and more aggressive on shock and vibration. Mounting design matters more than sealing, and the charge sources are usually a mix of solar, alternator and shore power — three sources with different characteristics all needing to respect the same charge profile.

Where an alternator charges the house bank while driving, a DC-DC charger with a lithium profile is usually required. Charging directly from a vehicle alternator, whose regulator is set for a lead-acid starter battery, will undercharge or overcharge the pack depending on the regulator.

Discharge unused, charge with care

Two failure modes account for most marine and RV warranty claims we see:

Charging below 0 °C, which causes permanent lithium plating. Cold-climate users need low-temperature charge protection, and the pack must still permit discharge so the system is usable.
Deep storage at full charge, which accelerates calendar ageing. A pack left at 100 % through a winter will lose more capacity than one stored at 50–60 %, whatever the cycle count says.

Both are avoidable with the right variant and a clear storage instruction. We would rather explain them at the point of sale than diagnose them afterwards.

FAQ

Is LiFePO4 safe on a boat?

LiFePO4 is the most thermally stable of the common lithium chemistries and does not exhibit the thermal runaway behaviour associated with other types. With a qualified BMS providing over-current, over-voltage, temperature and short-circuit protection, it is a well-established choice for marine house banks. The important condition is a properly matched, complete pack rather than self-assembled cells.

Why specify a salt spray test if the pack is IP65?

The IP rating covers ingress of water and particles under defined test conditions. It does not describe the corrosion behaviour of fasteners, terminals and the enclosure coating over years of salt exposure. For marine installations both are relevant, and we test for both where the product is intended for that environment.

What current does a bow thruster need?

Bow thrusters commonly draw 300–600 A at 12 V or 24 V for short periods, which is more than most house bank packs are rated for. Thrusters are usually served by a dedicated battery, or by a pack specified with a much higher BMS rating. Give us the thruster's rated current and duration and we will size accordingly rather than assume the house bank can carry it.

How do I handle winter storage?

Charge to about 50–60 %, disconnect the load, and recharge every three to six months. Leaving a pack at full charge in the cold accelerates calendar ageing, and leaving it fully discharged risks the BMS entering a low-voltage protection state that may need a recovery charge. Storage instructions come with every pack.