How to Mount and Secure Lithium Batteries on a Boat

Equipment and information required

Choose the location for the boat's sake first
Low and near the centreline. Lithium's weight saving is real, but several packs still represent significant mass, and high or outboard is the wrong place for it in a seaway.
Restrain against movement in every direction
Including upward. A knockdown or a roll should not move the bank. Fore-and-aft restraint alone is the common shortfall, and a pack that shifts takes its cable with it.
Keep it dry and out of the bilge
Lithium packs are not submersible and their terminals corrode like any other. Above any expected bilge water, with drainage away from the pack.
Cover the terminals
Insulating covers, and nothing metal stored where it could fall across them. A dropped spanner across a lithium terminal pair is a very different event from the same mistake on a flooded battery.
Respect the temperature range
Check the pack's charge and discharge temperature limits and keep it out of direct engine-bay heat. Australian summer temperatures in an enclosed compartment can exceed what the datasheet allows.
Leave access for service
You will need to reach the terminals, read the BMS and replace a fuse. A bank glassed into an inaccessible locker is a problem deferred, not solved.

More on installing