Improved power management for v2 RNodes and T-Beam devices

Config.h

@@ -306,7 +306,9 @@
     #define BATTERY_STATE_CHARGING 0x02
     #define BATTERY_STATE_CHARGED 0x03
     bool battery_installed = false;
+    bool battery_indeterminate = false;
     bool external_power = false;
+    bool battery_ready = false;
     float battery_voltage = 0.0;
     float battery_percent = 0.0;
     uint8_t battery_state = 0x00;