Are Lithium Batteries a Good Choice for Marine Cranking?


Hi PYS, I got two 200-ah lifepo4 batteries for my house bank and was contemplating getting a 100-ah lifepo4 for a start battery. Could you advise whether this is a sufficient battery to start my 40hp Yanmar engine? Thanks, Steve.


Hi Steve, Due to their large current, LiFeP04 batteries are not designed for starting or thruster loads. The limitation is mostly due to the BMS system but it is also due to safety of the cells. We are not aware of any manufacturer producing LiFeP04 batteries that are marketing them for starting loads, its would be possible in an emergency but not advised for day to day operation. Sticking with a quality AGM starter battery is the best bet.