Lithium iron phosphate (LiFePO4) batteries give you far more usable capacity for their weight, faster charging and a much longer life than lead-acid. A good conversion is more than swapping batteries, though, and on Lake Michigan cold is part of the design.
Why boat owners switch
- More usable power: you can use most of a lithium bank's capacity, compared with about half of a lead-acid bank's.
- Less weight: often well under half the weight for the same usable energy.
- Faster charging: lithium accepts high charge rates, so less time is spent running the engine or generator to recharge.
- Longer life: many more charge cycles, with steady voltage until the bank is nearly empty.
Cold-weather design for Chicago
LiFePO4 batteries must not be charged below freezing. Doing it damages the cells. In Chicago that's a real concern in April, late in the fall, and for any boat that stays connected during winter storage. We spec batteries and a battery management system (BMS) with low-temperature charge protection, set every charging source to respect it, and plan how the bank will be stored over winter.
What a proper conversion includes
- Battery and BMS selection sized for your loads, with low-temperature charge cutoff.
- Charging profiles on every source: shore charger, inverter/charger, solar controller and alternator.
- Alternator protection: a lithium bank can pull more current than a stock alternator can safely give. A DC-DC charger or an external regulator prevents an overheated or failed alternator.
- Overcurrent protection rated for lithium's high fault current, close to the battery.
- Monitoring so you can see state of charge and BMS status.
- A lead-acid starting battery kept separate where that's the safer design.
Schedule it over the winter
A conversion touches most of the charging system, which makes it an ideal fall or winter project while the boat is on the hard. It's tested and ready when you launch.
Request a quote and tell us your current batteries, charging sources and how you use the boat.