diff --git a/include/i2c.h b/include/i2c.h
index ed042b31..0975893c 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -14,5 +14,7 @@
 void i2c_init(void);
 void i2c_deinit(void);
 int i2c_scan(void);
+uint8_t i2c_readBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len);
+uint8_t i2c_writeBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len);
 
 #endif
\ No newline at end of file
diff --git a/include/power.h b/include/power.h
index 40e1a010..2db12da5 100644
--- a/include/power.h
+++ b/include/power.h
@@ -22,8 +22,6 @@ void AXP192_powerevent_IRQ(void);
 void AXP192_power(pmu_power_t powerlevel);
 void AXP192_init(void);
 void AXP192_showstatus(void);
-uint8_t i2c_writeBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len);
-uint8_t i2c_readBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len);
 
 #endif // HAS_PMU
 
diff --git a/src/i2c.cpp b/src/i2c.cpp
index 4fe58adc..4947ed05 100644
--- a/src/i2c.cpp
+++ b/src/i2c.cpp
@@ -88,4 +88,52 @@ int i2c_scan(void) {
     ESP_LOGE(TAG, "I2c bus busy - scan error");
 
   return devices;
-}
\ No newline at end of file
+}
+
+// mutexed functions for i2c r/w access
+uint8_t i2c_readBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len) {
+  if (I2C_MUTEX_LOCK()) {
+
+    uint8_t ret = 0;
+    Wire.beginTransmission(addr);
+    Wire.write(reg);
+    Wire.endTransmission(false);
+    uint8_t cnt = Wire.requestFrom(addr, (uint8_t)len, (uint8_t)1);
+    if (!cnt)
+      ret = 0xFF;
+    uint16_t index = 0;
+    while (Wire.available()) {
+      if (index > len) {
+        ret = 0xFF;
+        goto finish;
+      }
+      data[index++] = Wire.read();
+    }
+
+  finish:
+    I2C_MUTEX_UNLOCK(); // release i2c bus access
+    return ret;
+  } else {
+    ESP_LOGW(TAG, "[%0.3f] i2c mutex lock failed", millis() / 1000.0);
+    return 0xFF;
+  }
+}
+
+uint8_t i2c_writeBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len) {
+  if (I2C_MUTEX_LOCK()) {
+
+    uint8_t ret = 0;
+    Wire.beginTransmission(addr);
+    Wire.write(reg);
+    for (uint16_t i = 0; i < len; i++) {
+      Wire.write(data[i]);
+    }
+    ret = Wire.endTransmission();
+
+    I2C_MUTEX_UNLOCK(); // release i2c bus access
+    return ret ? ret : 0xFF;
+  } else {
+    ESP_LOGW(TAG, "[%0.3f] i2c mutex lock failed", millis() / 1000.0);
+    return 0xFF;
+  }
+}
diff --git a/src/power.cpp b/src/power.cpp
index 2afe9d25..80d961cd 100644
--- a/src/power.cpp
+++ b/src/power.cpp
@@ -147,55 +147,6 @@ void AXP192_init(void) {
   }
 }
 
-// helper functions for mutexing pmu i2c access
-uint8_t i2c_readBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len) {
-  if (I2C_MUTEX_LOCK()) {
-
-    uint8_t ret = 0;
-    Wire.beginTransmission(addr);
-    Wire.write(reg);
-    Wire.endTransmission(false);
-    uint8_t cnt = Wire.requestFrom(addr, (uint8_t)len, (uint8_t)1);
-    if (!cnt)
-      ret = 0xFF;
-    uint16_t index = 0;
-    while (Wire.available()) {
-      if (index > len) {
-        ret = 0xFF;
-        goto finish;
-      }
-      data[index++] = Wire.read();
-    }
-
-  finish:
-    I2C_MUTEX_UNLOCK(); // release i2c bus access
-    return ret;
-  } else {
-    ESP_LOGW(TAG, "[%0.3f] i2c mutex lock failed", millis() / 1000.0);
-    return 0xFF;
-  }
-}
-
-uint8_t i2c_writeBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len) {
-  if (I2C_MUTEX_LOCK()) {
-
-    uint8_t ret = 0;
-    Wire.beginTransmission(addr);
-    Wire.write(reg);
-    for (uint16_t i = 0; i < len; i++) {
-      Wire.write(data[i]);
-    }
-    ret = Wire.endTransmission();
-
-    I2C_MUTEX_UNLOCK(); // release i2c bus access
-    // return ret ? 0xFF : ret;
-    return ret ? ret : 0xFF;
-  } else {
-    ESP_LOGW(TAG, "[%0.3f] i2c mutex lock failed", millis() / 1000.0);
-    return 0xFF;
-  }
-}
-
 #endif // HAS_PMU
 
 void calibrate_voltage(void) {