"These batteries are utter rubbish. They state to be alkaline but they last about a tenth of the old zinc carbon batteries. I use them in a quartz clock and after about three weeks the clock goes slow because the battery is exhausted! Yesterday I used them in a small Christmas light string with about 10 LEDs and they barely lasted about 6 hours. A pair of old rechargeable AA NiMeHydrate batteries will drive the lights for about three days continuously."