These industrial size D batteries never have failed us here in my household. We use them in battery candles and we keep the candles on 24-7 and have noticed we get more life out of each battery this way; The batteries have a charge that lasts for about 6 weeks straight, never turning them off (We do notice that some manufacturers of the flameless deco candles are more efficient than others, however. Watch the kind of battery operated flameless candles you buy! Get highly rated candles and place your industrial strength batteries in THESE type of candles. Don’t think your saving when you buy a cheaper quality - cheap does become expensive in the short and long run!)!