Panasonic EY9L45B 144V 42ah Li Ion Battery p Description This Panasonic 144v 42 Ah Liion battery EY9L45B is Panasonic &39s largest battery yet providing superior runtime with the same 144v power & low weight It is compatible with the EY0L81B & EY0L82B chargers Lithiumion batteries present several advantages over Ni MH & Ni Cd batteries including no memory effect no lazy battery effect reduced selfdischarge rates & the ability to withstand colder temperatures in working order