By Boat Battery editorial team · 2 minute read · Editorial policy
Not below 0 °C without low-temperature protection or heating. Discharging is fine; it is charging that damages cold cells, permanently and invisibly.
Low-temperature charging damage
Charging LiFePO4 below freezing causes lithium plating on the anode. It is cumulative, it is irreversible, and it does not announce itself: the battery accepts the charge, works normally, and simply has less capacity and a shorter life than it should.
Discharge limits differ from charge limits
Discharge is a different matter. A cold LiFePO4 bank will happily run your loads down to well below zero, with reduced capacity that returns when it warms. The asymmetry surprises people.
Cold-weather storage and solar charging
For most Australian boats this is a non-issue for most of the year. It becomes real in a Tasmanian or alpine winter, on a pre-dawn launch on the southern coast, and in unheated winter storage where a solar panel keeps trying to charge a frozen bank all season. That last case is the one that quietly kills batteries.
Charge cut-off and heated battery controls
Two solutions. A BMS with a low-temperature charge cut-off simply refuses charge below a set temperature; this is now standard on reputable packs and should be on your specification. A heated pack draws a little power to warm the cells before accepting charge, and is worth it on a boat that winters south.
Related installation planning resources
Use these notes to prepare your own measurements and questions. Check the exact equipment manuals and have the proposed system assessed for your vessel before buying or changing electrical components.
Calculate your boat battery capacity
The house bank calculator takes your loads, your nights on the hook, your solar and your alternator, and returns the bank, the DC-DC charger, the AGM equivalent and the weight you take off the boat.
Open the calculator