Backup Battery Harness for LXNAV S3 Variometer, LXNAV ADI (Airdata Indicator), or LXNAV G-Meter

Cable, 1 m (3.281 ft)

Backup power pack for the LXNAV S3, LXNAV ADI (Airdata Indicator) and LXNAV G-Meter with 12V power leads for connection to the glider's 12V power system and a 8 x AA battery holder (batteries not included) and a panel-mountable 3-position ON/OFF/Backup switch and RJ12 connector for connection to the LXNAV S3, ADI, or G-Meter.

The red and black power leads connect to the glider's 12V power system for powering the instrument most of the time. If the main glider battery gets low you simply switch the 3-position switch from ON to Backup.  The instrument will shut-down during the switch from ON to OFF to Backup.

The system does not attempt to charge the AA batteries. Since you'll probably use the batteries only rarely, you should be able to change them only once a year.

Backup Battery Life
(8 x new AA Duracell Alkaline)

• LXNAV S3: 17+ hours
• LXNAV ADI (Airdata Indicator): 11+ hours
• LXNAV G-Meter: 12+ hours
  

LXNAV S3 Backup Battery Testing
I tested using 8 fresh AA Duracell Alkaline batteries with the S3 screen on full brightness and the speaker at a low volume. The initial S3 voltage readout was 12.5 volts. After 17 hours and 27 minutes the S3 vario shut-down. The S3's voltage display was reading less then 6V just before it shut-down. 

LXNAV ADI (Airdata Indicator) Backup Battery Testing
I tested using 8 fresh AA Duracell Alkaline batteries with the ADI screen on full brightness and the temperature probe attached. The initial ADI voltage readout was 12.5 volts. I ran the test twice. It shutdown once after 11.5 hours and once after 12 hours.  The ADI's voltage display was reading less then 6V just before it shut-down. 

LXNAV G-Meter Backup Battery Testing
I tested using 8 fresh AA Duracell Alkaline batteries with the G-Meter screen on full brightness  The G-Meter backlight went a bit dim at about 12 hours and shutdown shortly after.