Lithium house batteries in Boat Talk Posted 14 hours ago 2 hours ago, Was_Wylie_Tunes said: Its a hard no, for me. There are two types, you have lithium -ion and lithium polymer. The ion is the type you have to worry more about. Now the type that go into our boats is ion, but they have built into the battery a "Battery Management System". Not to get into it here, but it makes the battery a lot safer. Unlike cell phones! The down side, about 4x the price of an AGM . The up side is that there 1/2 the wight and can discharge around 40 to 30%. I would wait another 2 to 4 years for a price drop.