diff --git a/current.txt b/current.txt
index e19fc12..7c5ba99 100644
--- a/current.txt
+++ b/current.txt
@@ -622,7 +622,7 @@
 f284ffde7cadf5a1364b75ab313baf22401eeca289bdde2a2dc7a27ea4ab98d7 android.hardware.dumpstate@1.1::IDumpstateDevice
 ce8dbe76eb9ee94b46ef98f725be992e760a5751073d4f4912484026541371f3 android.hardware.health@2.1::IHealth
 26f04510a0b57aba5167c5c0a7c2f077c2acbb98b81902a072517829fd9fd67f android.hardware.health@2.1::IHealthInfoCallback
-3a4e7462a12589bd219599de59663d0ba9915313f45150774780d09f4e114f74 android.hardware.health@2.1::types
+e2f8bc1868fd4a3fd587c172773ea5a8c2f5a3deaf7958394102ca455252b255 android.hardware.health@2.1::types
 0589e410f519e36514e7ece18f283f022df0f70efd2c12821d822f67f74aba98 android.hardware.identity@1.0::types
 bbeee9604128ede83ee755b67e73b5ad29e6e1dbac9ec41fea6ffe2745b0c50a android.hardware.identity@1.0::IIdentityCredential
 96ce8aad80f4c476f25261f790d357c117e79e18474c7dadd850dac704bbe65e android.hardware.identity@1.0::IIdentityCredentialStore
diff --git a/health/2.1/types.hal b/health/2.1/types.hal
index be1eaf8..d775491 100644
--- a/health/2.1/types.hal
+++ b/health/2.1/types.hal
@@ -19,6 +19,10 @@
 import @1.0::HealthConfig;
 import @2.0::HealthInfo;
 
+enum Constants : int64_t {
+    BATTERY_CHARGE_TIME_TO_FULL_NOW_SECONDS_UNSUPPORTED = -1,
+};
+
 /**
  * Battery capacity level. This enum provides additional information along side
  * with the battery capacity.
@@ -27,11 +31,17 @@
  */
 enum BatteryCapacityLevel : int32_t {
     /**
+     * Battery capacity level is unsupported.
+     * Battery capacity level must be set to this value if and only if the
+     * implementation is unsupported.
+     */
+    UNSUPPORTED = -1,
+    /**
      * Battery capacity level is unknown.
      * Battery capacity level must be set to this value if and only if battery
-     * is not present.
+     * is not present or the battery capacity level is unknown/uninitialized.
      */
-    UNKNOWN = 0,
+    UNKNOWN,
     /**
      * Battery is at critical level. The Android framework must schedule a
      * shutdown when it sees this value from the HAL.
@@ -78,6 +88,8 @@
 
     /**
      * Estimated time to fully charge the device (in seconds).
+     * Value must be BATTERY_CHARGE_TIME_TO_FULL_NOW_SECONDS_UNSUPPORTED if and
+     * only if the implementation is unsupported.
      * Value must be 0 if and only if batteryCapacityLevel is FULL or UNKNOWN.
      * Otherwise, value must be positive.
      */