It's just under the battery cover on the left and 'pops' straight out. In a battery rundown test with the compass ON, the unit lasted 18 1/2 hours.
This new Garmin (H)igh sensitivity receiver (C)olor unit contains the (x) micro SD card slot.
(The GPSmap 76Cx was able to detect walking movements less than 1.0 mph.) Also, the alarm clock available in the Vista/Legend C(x) has been removed from the HCx. The below HCx pressure plot is not as versatile as that of the Vista C, which records the pressure even though the unit is turned off. In the first two screen shots, the barometer was calibrated to 1500 feet (in the Fixed Elevation mode), where the actual altitude was about 1,100 feet.
In approximately an hour and a half, this large error was basically wiped out.
Moving the Click Stick activates movable crosshairs to read out Elevation and Time along the plot.
The above plot is similar to () plot of the GPSmap 76S barometric and GPS altitudes with only 100-foot initial calibration error.
Unlike the GPSmap 76S, the GPSmap 76CS(x) and Vista (H)C(x) don't show a continuous readout of GPS altitude. GPS altitude must be accessed from the Satellite Page by pressing Menu Key, then select GPS Elevation.
This is a "one time" reading, and is not continuous.
There we placed a Vista HCx, Vista C, and GPSmap 76Cx over the marker and took error readings every minute for ten minutes on three separate visits.
The overall averages were: Vista HCx=6.0 feet, Vista C=5.3 feet, and a GPSmap 76Cx=7.4 feet (no significant difference in accuracy) -all well within the expected WAAS-corrected error of 10 feet.
A similar procedure is required in the original Vista.