... : 4V 4Ah.5.Strong power rechargeable battery with working time over 2 months.6.With the function of auto zero tracking ... ,tare,50 price memories,delete,accumulate,price auto computing,change,etc..7.Asleep mode to prolong the work time of ... with removeable stainless steel panKey functionsZero, tare,accumulation,clear, add, change,backlight switch and numeral keys. digital scale