The TireMinder Bluetooth Adapter uses a Micro USB style charger to charge the internal lithium-ion battery. The light on the bottom of the adapter will disappear when it is fully charged (~6 hours to fully charge).
If the battery becomes low, you will receive an alert/notification on your phone. The TireMinder Bluetooth Adapter can be used while charging. The adapter’s battery charge will last between 2 to 4 weeks on a single charge (depending on use).