Your sensor puck will flash yellow after reset when your battery is running low and will flash red when the battery is extremely low and needs to be charged immediately. (Note: Battery charge lasts around 10-14 days depending on your settings)
To charge, turn the bottle upside down and remove the puck to charge.
Place the puck on a flat surface and attach the magnetic end of the HidrateSpark charging cable to the puck. While charging every other LED on your puck will illuminate and fade in / out (every 10 sec.) green. Once fully charged every other LED on your puck will remain SOLID GREEN. It may take up to a few hours to charge the bottle. After charging and reassembling the bottle, the sensor has to be recalibrated within the app.
NOTE: Please avoid putting the charging cable near metal surfaces when it's not in use. If the cable comes close enough to a metal surface, it may connect to that surface with its magnets and cause damage to the cable
Please DO NOT try charging the bottle with any cables other than the one that came with the bottle as it may damage the sensor!