If the Keddle has not been charged in at least 10 days, it will need to reboot. The reboot process takes about 5 minutes. After the Keddle is done rebooting, the screen will display 'charging'. Please remember to use the original charging accessories, otherwise the Keddle may not reboot properly. The Keddle does not turn off which means that the Keddle will lose between 5% and 8% of battery charge per day when not in use. We recommend keeping your Keddle charged each night otherwise the Keddle battery will slowly lose battery power even when its not used. Do not let your Keddle sit unused for months at a time. This will damage the battery. You can charge your Keddle at any time including during a warming cycle, however, if your battery is low, the Keddle may stop warming. Charge your Keddle for at least 20 minutes to warm 1 bottle. It can take 4 hours to fully charge your Keddle using a standard 120V power outlet. Never warm or charge your Keddle with a portable battery pack. Doing so may damage your Keddle. The Keddle is designed to warm up to 32 oz of water from 78°F to 98°F on a single charge which is the equivalent of eight 4 oz bottles or four 8 oz bottles (the Keddle can warm 25oz of water from refrigerated temperature to 98° on a full charge). As with most batteries, you should expect to see the battery begin to lose battery capacity over time which means that you eventually will not be able to warm as much liquid or food on a single charge. This is especially true if you have more than one baby that you warm bottles for (e.g. a twin or a second baby). We can replace the battery for $30 (which includes shipping from and to your house). Warming breast milk bags takes more energy which means you'll need to charge more often compared to warming liquids directly. You can charge your Keddle using a standard power outlet (120V) or an automobile USB outlet (12V). Do not use 3rd party power adaptors or power cords to charge your Keddle. Charging your Keddle using a USB outlet will take longer. Unplug your Keddle if it will not be used for an extended amount of time.