diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus.cpp b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus.cpp
index 5a37e36dd2..4334f521b7 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus.cpp
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus.cpp
@@ -46,71 +46,61 @@ void AP_BattMonitor_SMBus::read(void)
 }
 
 // reads the pack full charge capacity
-// returns true if the read was successful, or if we already knew the pack capacity
-bool AP_BattMonitor_SMBus::read_full_charge_capacity(void)
+// returns if we already knew the pack capacity
+void AP_BattMonitor_SMBus::read_full_charge_capacity(void)
 {
     if (_full_charge_capacity != 0) {
-        return true;
+        return;
     }
 
     if (read_word(BATTMONITOR_SMBUS_FULL_CHARGE_CAPACITY, _full_charge_capacity)) {
         _full_charge_capacity *= get_capacity_scaler();
-        return true;
     }
-    return false;
 }
 
 // reads the remaining capacity
-// returns true if the read was successful, which is only considered to be the
-// we know the full charge capacity
-bool AP_BattMonitor_SMBus::read_remaining_capacity(void)
+// which will only be read if we know the full charge capacity (accounting for battery degradation)
+void AP_BattMonitor_SMBus::read_remaining_capacity(void)
 {
     int32_t capacity = _params._pack_capacity;
 
-    if (capacity > 0) {
-        uint16_t data;
-        if (read_word(BATTMONITOR_SMBUS_REMAINING_CAPACITY, data)) {
-            _state.consumed_mah = MAX(0, capacity - (data * get_capacity_scaler()));
-            return true;
-        }
+    if (capacity <= 0) {
+        return;
     }
 
-    return false;
+    uint16_t data;
+    if (read_word(BATTMONITOR_SMBUS_REMAINING_CAPACITY, data)) {
+        _state.consumed_mah = MAX(0, capacity - (data * get_capacity_scaler()));
+    }
 }
 
 // reads the temperature word from the battery
-// returns true if the read was successful
-bool AP_BattMonitor_SMBus::read_temp(void)
+void AP_BattMonitor_SMBus::read_temp(void)
 {
     uint16_t data;
-    if (read_word(BATTMONITOR_SMBUS_TEMP, data)) {
+    if (!read_word(BATTMONITOR_SMBUS_TEMP, data)) {
         _has_temperature = (AP_HAL::millis() - _state.temperature_time) <= AP_BATT_MONITOR_TIMEOUT;
-
-        _state.temperature_time = AP_HAL::millis();
-        _state.temperature = ((float)(data - 2731)) * 0.1f;
-        return true;
+        return;
     }
-    
-    _has_temperature = false;
+    _has_temperature = true;
 
-    return false;
+    _state.temperature_time = AP_HAL::millis();
+    _state.temperature = (data * 0.1f) - C_TO_KELVIN;
 }
 
 // reads the serial number if it's not already known
-// returns true if the read was successful or the number was already known
-bool AP_BattMonitor_SMBus::read_serial_number(void)
+// returns if the serial number was already known
+void AP_BattMonitor_SMBus::read_serial_number(void)
 {
-    uint16_t data;
-
     // don't recheck the serial number if we already have it
     if (_serial_number != -1) {
-        return true;
-    } else if (read_word(BATTMONITOR_SMBUS_SERIAL, data)) {
-        _serial_number = data;
-        return true;
+        return;
     }
 
-    return false;
+    uint16_t data;
+    if (read_word(BATTMONITOR_SMBUS_SERIAL, data)) {
+        _serial_number = data;
+    }
 }
 
 // reads the battery's cycle count
diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus.h b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus.h
index 52ffb173e7..0accd937df 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus.h
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus.h
@@ -59,24 +59,21 @@ protected:
     void read(void) override;
 
     // reads the pack full charge capacity
-    // returns true if the read was successful, or if we already knew the pack capacity
-    bool read_full_charge_capacity(void);
+    void read_full_charge_capacity(void);
 
     // reads the remaining capacity
-    // returns true if the read was successful, which is only considered to be the
-    // we know the full charge capacity
-    bool read_remaining_capacity(void);
+    // which will only be read if we know the full charge capacity (accounting for battery degradation)
+    void read_remaining_capacity(void);
 
     // return a scaler that should be multiplied by the battery's reported capacity numbers to arrive at the actual capacity in mAh
     virtual uint16_t get_capacity_scaler() const { return 1; }
 
     // reads the temperature word from the battery
-    // returns true if the read was successful
-    virtual bool read_temp(void);
+    virtual void read_temp(void);
 
     // reads the serial number if it's not already known
-    // returns true if the read was successful, or the number was already known
-    bool read_serial_number(void);
+    // returns if the serial number was already known
+    void read_serial_number(void);
 
     // reads the battery's cycle count
     void read_cycle_count();
diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Rotoye.cpp b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Rotoye.cpp
index 25e5b5d393..d649346b49 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Rotoye.cpp
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Rotoye.cpp
@@ -6,7 +6,7 @@
 #define BATTMONITOR_SMBUS_TEMP_EXT 0x07
 
 // return the maximum of the internal and external temperature sensors
-bool AP_BattMonitor_SMBus_Rotoye::read_temp(void) {
+void AP_BattMonitor_SMBus_Rotoye::read_temp(void) {
     
     uint16_t t_int, t_ext;
     
@@ -18,8 +18,5 @@ bool AP_BattMonitor_SMBus_Rotoye::read_temp(void) {
         _state.temperature_time = AP_HAL::millis();
         t = ((t_ext > t_int) ? t_ext : t_int);
         _state.temperature = 0.1f * (float)t - C_TO_KELVIN;
-        return true;
     }
-
-    return false;
 }
diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Rotoye.h b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Rotoye.h
index 126b558a83..abc5835bfe 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Rotoye.h
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Rotoye.h
@@ -9,6 +9,6 @@ class AP_BattMonitor_SMBus_Rotoye : public AP_BattMonitor_SMBus_Generic
 private:
 
     // Rotoye Batmon has two temperature readings
-    bool read_temp(void) override;
+    void read_temp(void) override;
 
 };
\ No newline at end of file