Update Power_capabilities.md

Author: chipguyhere

docs/Power_capabilities.md

@@ -3,8 +3,8 @@
 Document v0.1
 
 The power management capabilities are provided by the IP5306 power controller, specifically the IP5306_I2C version of the controller,
-that can be accessed on the I2C bus at address 0x75.  Access is possible using the `POWER` class,
-located in `Power.h` and `Power.cpp`, automatically included with `#include "M5Stack.h"`.
+that can be accessed on the I2C bus at address 0x75.  Access is possible via M5.Power, which is implemented in
+`src/utility/Power.h` and `src/utility/Power.cpp`, and becomes available with `#include "M5Stack.h"`.
 
 ### Capabilities
 
@@ -15,7 +15,7 @@ located in `Power.h` and `Power.cpp`, automatically included with `#include "M5S
      No, since it doesn't have a real-time clock chip (RTC), but ESP32 sleep modes may provide a suitable alternative.
 - **Can it tell if it is running on external versus battery power?** If `isCharging()` or `isChargeFull()` true, probably on external power.
 - **Can it detect the rate of charge or discharge?** *probably not, but inference can probably be made by comparing `isChargeFull()` to the charge full current cutoff*
-- **Can it tell if a battery is present or absent?** *possibly, but not formally*
+- **Can it tell if a battery is present or absent?** *possibly, but not formally... an absent battery seems to always be reported as "charging", having a level of "100%", and never becomes "charge full"*
 - **Can it tell the state of charge of the battery?** Yes, using `getBatteryLevel()`, which returns one of: 0, 25, 50, 75, 100 (representing a percentage), or -1 (if unable to read)
 - **Can it read its battery voltage?** Not possible to read the voltage level directly, only the approximate percentage of 0/25/50/75/100.
 - **Can communication with the IP5306 power controller be tested and confirmed?** Yes, with `canControl()`