diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_PX4.cpp b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_PX4.cpp
index b5bcdda5f5..f583db180d 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_PX4.cpp
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_SMBus_PX4.cpp
@@ -71,7 +71,6 @@ void AP_BattMonitor_SMBus_PX4::read()
             _state.healthy = true;
 
             // read capacity
-            uint32_t tnow = hal.scheduler->micros();
             if ((_batt_fd >= 0) && !_capacity_updated) {
                 uint16_t tmp;
                 if (ioctl(_batt_fd, BATT_SMBUS_GET_CAPACITY, (unsigned long)&tmp) == OK) {