define BatteryService BLEUUID((uint16_t)0x180F)

BLECharacteristic BatteryLevelCharacteristic(BLEUUID((uint16_t)0x2A19), BLECharacteristic::PROPERTY_READ | BLECharacteristic::PROPERTY_NOTIFY);

BLEDescriptor BatteryLevelDescriptor(BLEUUID((uint16_t)0x2901));

BLECharacteristic BatteryVoltageCharacteristic(BLEUUID((uint16_t)0x2BF0), BLECharacteristic::PROPERTY_READ | BLECharacteristic::PROPERTY_NOTIFY);

BLEDescriptor BatteryVoltageDescriptor(BLEUUID((uint16_t)0x2901));