SGP/EBBR/E15 - Battery Voltage Drop

From the installation of the changeout unit at E15 on 15 December 1995, the
battery exhibited a slow decline in voltage. However, after a day of the
AEM not operating, site operations restarted the AEM on 20 December 1995 and
the battery condition declined more rapidly, such that the solar panel was not
able to keep the battery voltage up (greater than 11 V DC) for nighttime
conditions, even after a cloudless day.  Battery voltage first dropped below 11
volts at 0635 GMT on 21 December.  I requested that the solar panel voltage
regulator be tested.  On 16 January 1996, site operations found that the
fuse in the solar panel voltage regulator was loose.  After the fuse was
repositioned, the battery voltage increased almost immediately to 13.5
volts and has been good since.

All data for the periods above should be considered incorrect; many sensors
require at least 11 volts DC power and the performance of the CR10 data
logger can not be trusted at less than 11 volts.

• time_offset
• temp_air_bottom
• vapor_pressure_top
• temp_air_top
• rh_bottom_fraction
• wspd_arith_mean
• vapor_pressure_bottom
• wdir_vec_std
• rh_top_fraction
• lon
• temp_reference
• temp_trh_bottom
• temp_trh_top
• home_signal
• wspd_vec_mean
• alt
• wdir_vec_mean
• net_radiation
• lat
• base_time
• atmos_pressure

• lon
• soil_heat_flow_2_mv
• atmos_pressure_mv
• rh_right_mv
• soil_heat_flow_5_mv
• soil_temp_5_rr
• soil_moisture_1_r
• soil_moisture_5_r
• battery_voltage
• temp_reference_rr
• base_time
• soil_heat_flow_3_mv
• net_radiation_mv
• soil_temp_3_rr
• soil_moisture_4_r
• temp_air_left
• soil_temp_4_rr
• rh_left_mv
• wdir_vec_mean_mv
• home_signal
• soil_heat_flow_1_mv
• lat
• soil_temp_1_rr
• temp_air_right
• temp_trh_left_rr
• soil_moisture_3_r
• alt
• soil_heat_flow_4_mv
• soil_temp_2_rr
• temp_trh_right_rr
• wspd_arith_mean
• soil_moisture_2_r
• time_offset

• soil_moisture_1
• soil_moisture_2
• soil_moisture_3
• temp_air_bottom
• soil_moisture_4
• soil_moisture_5
• corr_soil_heat_flow_4
• corr_soil_heat_flow_3
• corr_soil_heat_flow_2
• corr_soil_heat_flow_1
• alt
• corr_soil_heat_flow_5
• surface_soil_heat_flux_avg
• wdir_vec_mean
• soil_heat_flow_4
• soil_heat_flow_5
• soil_heat_flow_2
• soil_heat_flow_3
• soil_heat_flow_1
• base_time
• soil_heat_capacity_5
• soil_heat_capacity_4
• temp_reference
• home_signal_15
• lat
• time_offset
• rh_bottom_fraction
• wspd_arith_mean
• soil_heat_capacity_3
• soil_heat_capacity_2
• soil_heat_capacity_1
• bowen_ratio
• lon
• wdir_vec_std
• latent_heat_flux
• surface_soil_heat_flux_5
• sensible_heat_flux
• surface_soil_heat_flux_3
• surface_soil_heat_flux_4
• atmos_pressure
• home_signal_30
• temp_trh_top
• vapor_pressure_top
• surface_soil_heat_flux_1
• surface_soil_heat_flux_2
• net_radiation
• energy_storage_change_1
• soil_temp_4
• vapor_pressure_bottom
• energy_storage_change_3
• soil_temp_3
• energy_storage_change_2
• energy_storage_change_5
• soil_temp_2
• energy_storage_change_4
• soil_temp_1
• soil_temp_5
• temp_trh_bottom
• rh_top_fraction
• temp_air_top
• wspd_vec_mean