SGP/EBBR/E4 - EBBR E4 Low Battery - Resulting In Incorrect Data

A low battery condition (less than 10.5 volts) caused a number of data
fields to be incorrect at some times and all data fields to be incorrect
at a more limited number of times.  All data fields are suspect when the
battery voltage drops below 10.5 volts because the CR10 cannot operate 
properly.  Some sensors are affected slightly (i.e. pressure) at slightly
larger voltages.  The low battery condition resulted from an initially 
weak battery and a week of extremely low solar radiation (from heavy 
cloudiness) on the solar panel that provides most of the charging of the
battery. 

Comments added by Marv Wesely: 
David Cook has been working with Dave Breedlove to try to assess the age
of the batteries.  The dates on the batteries need to be read during 
site visits and provided to David C.  It's quite possible that they need
to be replaced.  It's work in progress, though slow at times.

• Bottom air temperature(temp_air_bottom)
• Soil moisture 2, gravimetric(soil_moisture_2)
• Soil moisture 1, gravimetric(soil_moisture_1)
• Wind direction vector mean(wdir_vec_mean)
• lon(lon)
• Bottom relative humidity (fractional)(rh_bottom_fraction)
• Top T/RH sensor temperature(temp_trh_top)
• Soil heat capacity 4(soil_heat_capacity_4)
• Soil heat capacity 5(soil_heat_capacity_5)
• Soil heat capacity 2(soil_heat_capacity_2)
• Soil heat capacity 3(soil_heat_capacity_3)
• Soil moisture 4, gravimetric(soil_moisture_4)
• Soil moisture 3, gravimetric(soil_moisture_3)
• Soil moisture 5, gravimetric(soil_moisture_5)
• Net radiation(net_radiation)
• Soil heat capacity 1(soil_heat_capacity_1)
• base time in epoch(base_time)
• Soil heat flow 3, corrected for soil moisture(corr_soil_heat_flow_3)
• Soil heat flow 4, corrected for soil moisture(corr_soil_heat_flow_4)
• Soil heat flow 5, corrected for soil moisture(corr_soil_heat_flow_5)
• Soil heat flow 1(soil_heat_flow_1)
• Soil heat flow 3(soil_heat_flow_3)
• Soil heat flow 2(soil_heat_flow_2)
• Soil heat flow 5(soil_heat_flow_5)
• Soil heat flow 4(soil_heat_flow_4)
• Wind direction vector mean standard deviation(wdir_vec_std)
• Soil heat flow 1, corrected for soil moisture(corr_soil_heat_flow_1)
• Soil heat flow 2, corrected for soil moisture(corr_soil_heat_flow_2)
• Half hour averaged soil temperature 5(soil_temp_5)
• Half hour averaged soil temperature 4(soil_temp_4)
• Soil temperature mean 3(soil_temp_3)
• Soil temperature 2(soil_temp_2)
• Soil temperature 1(soil_temp_1)
• AEM position indicator 15 to 30 mins(home_signal_30)
• Surface sensible heat flux(sensible_heat_flux)
• Wind speed arithmetic mean(wspd_arith_mean)
• Top air temperature(temp_air_top)
• Top relative humidity (fractional)(rh_top_fraction)
• Atmospheric pressure(atmos_pressure)
• Bottom T/RH sensor temperature(temp_trh_bottom)
• Wind speed vector mean(wspd_vec_mean)
• Surface soil heat flux, average of fluxes 1-5(surface_soil_heat_flux_avg)
• Change in energy storage 3, 0-5 cm soil layer(energy_storage_change_3)
• Change in energy storage 2, 0-5 cm soil layer(energy_storage_change_2)
• Change in energy storage 1, 0-5 cm soil layer(energy_storage_change_1)
• Change in energy storage 5, 0-5 cm soil layer(energy_storage_change_5)
• Change in energy storage 4, 0-5 cm soil layer(energy_storage_change_4)
• AEM position indicator 0 to 15 mins(home_signal_15)
• North Latitude(lat)
• Top vapor pressure(vapor_pressure_top)
• -180.0 - +180.0(alt)
• Bottom vapor pressure(vapor_pressure_bottom)
• Bowen ratio(bowen_ratio)
• Reference temperature in enclosure(temp_reference)
• Surface soil heat flux 5(surface_soil_heat_flux_5)
• Surface soil heat flux 3(surface_soil_heat_flux_3)
• Surface soil heat flux 4(surface_soil_heat_flux_4)
• Surface soil heat flux 1(surface_soil_heat_flux_1)
• Time offset from base_time(time_offset)
• Surface soil heat flux 2(surface_soil_heat_flux_2)
• Surface latent heat flux(latent_heat_flux)

• Wind speed arithmetic mean(wspd_arith_mean)
• lon(lon)
• Top relative humidity (fractional)(rh_top_fraction)
• Bottom T/RH sensor temperature(temp_trh_bottom)
• AEM position indicator(home_signal)
• Atmospheric pressure(atmos_pressure)
• Top T/RH sensor temperature(temp_trh_top)
• Bottom relative humidity (fractional)(rh_bottom_fraction)
• -180.0 - +180.0(alt)
• Net radiation(net_radiation)
• North Latitude(lat)
• Wind direction vector mean(wdir_vec_mean)
• Bottom air temperature(temp_air_bottom)
• Wind speed vector mean(wspd_vec_mean)
• base time in epoch(base_time)
• Top vapor pressure(vapor_pressure_top)
• Bottom vapor pressure(vapor_pressure_bottom)
• Top air temperature(temp_air_top)
• Time offset from base_time(time_offset)
• Wind direction vector mean standard deviation(wdir_vec_std)
• Reference temperature in enclosure(temp_reference)

• Wind speed arithmetic mean(wspd_arith_mean)
• Soil heat flow 3 (mV)(soil_heat_flow_3_mv)
• base time in epoch(base_time)
• Soil moisture 1 (resistance)(soil_moisture_1_r)
• lon(lon)
• Soil moisture 5 (resistance)(soil_moisture_5_r)
• Soil temperature 4 (resistance ratio)(soil_temp_4_rr)
• Atmospheric pressure (mV)(atmos_pressure_mv)
• Reference temperature in enclosure (resistance ratio)(temp_reference_rr)
• Right air temperature(temp_air_right)
• Soil temperature 1 (resistance ratio)(soil_temp_1_rr)
• Soil heat flow 5 (mV)(soil_heat_flow_5_mv)
• Soil moisture 2 (resistance)(soil_moisture_2_r)
• Left air temperature(temp_air_left)
• Right relative humidity (mV)(rh_right_mv)
• Soil temperature 3 (resistance ratio)(soil_temp_3_rr)
• Soil moisture 3 (resistance)(soil_moisture_3_r)
• Right T/RH sensor temperature (resistance ratio)(temp_trh_right_rr)
• Wind direction vector mean (mV)(wdir_vec_mean_mv)
• Soil heat flow 2 (mV)(soil_heat_flow_2_mv)
• AEM position indicator(home_signal)
• Battery voltage(battery_voltage)
• Left T/RH sensor temperature (resistance ratio)(temp_trh_left_rr)
• Soil heat flow 1 (mV)(soil_heat_flow_1_mv)
• Soil temperature 5 (resistance ratio)(soil_temp_5_rr)
• Soil moisture 4 (resistance)(soil_moisture_4_r)
• Left relative humidity (mV)(rh_left_mv)
• North Latitude(lat)
• Time offset from base_time(time_offset)
• -180.0 - +180.0(alt)
• Soil temperature 2 (resistance ratio)(soil_temp_2_rr)
• Soil heat flow 4 (mV)(soil_heat_flow_4_mv)
• Net radiation (mV)(net_radiation_mv)