Many still swear by this simple, flooded lead-acid technology, where you can top them up with distilled water every month or so and regularly test the capacity of each cell using a hydrometer. Lead-acid batteries remain cheaper than lithium iron phosphate batteries but they are heavier and take up more room on board.
It is now generally accepted by most of the marine industry’s regulatory groups that the safest chemical combination in the lithium-ion (Li-ion) group of batteries for use on board a sea-going vessel is lithium iron phosphate (LiFePO4).
While rumours about ‘lithium’ batteries causing fires are rife, most of these arise in the electric vehicle (EV) arena, where there have indeed been some quite frightening cases of the more volatile types of lithium-ion batteries bursting into flames and the fire services being unable to extinguish them quickly.
Besides, the fire effluents of LIBs can be more serious, containing lots of toxic gases such as carbon monoxide (CO) and hydrogen fluoride (HF). Larsson et al. conducted fire tests to estimate gas emissions of commercial lithium iron phosphate cells (LiFePO 4) exposed to a controlled propane fire.
Battery management is key when running a lithium iron phosphate (LiFePO4) battery system on board. Victron’s user interface gives easy access to essential data and allows for remote troubleshooting.
Researchers in the United Kingdom have analyzed lithium-ion battery thermal runaway off-gas and have found that nickel manganese cobalt (NMC) batteries generate larger specific off-gas volumes, while lithium iron phosphate (LFP) batteries are a greater flammability hazard and show greater toxicity, depending on relative state of charge (SOC).