The following 7 days another just one went and soon after 3 weeks all of them beeped. I,dont know very well what goimf on with greenback keep batteries However they used to be a bargain but currently they have been garbage. Convenient Options: Incredibly hot pad characteristics 2-hour auto-off; https://www.sunbeambattery.com/news/key-capture-energy-plans-to-build-a-new-battery-energy-storage-system-in-new-york-161123.html