That smart Device monitors your car or truck batteries to remain about 25 % of capacity for the engine start when you are using a lights, heaters, TV, laptops or something else during the parking or warn about a generator failure when driving.
There are the numerous another applications as well like a camping, boating, solar systems and so on.
The device does not discharge your battery during the monitoring since the supply current is about 1 mA based on the dead-proof Microchip microcontroller and well programmed to prevent both the deep discharge and false alarms from a temporary loads.
Green LED indicates a good state, Red LED is not ok, then sound alarm means your batteries need to be recharged.
Device should be wired as close to batteries as possible but input of a cab fuse panel would be ok.
The red wire is Plus (hot at all times), the black one is Ground (body or frame).
The using of a cigar lighter socket is a not a good idea because of a voltage drop by loads and junctions.
The sound alarm is pre-programmed at 11.9 - 12.0V, but if it is too early or late (depends of a wiring and batteries condition in the most) you can re-calibrate the device in 3 easy steps:
- Idle engine in a half of hour or fully charge your batteries another way
- Stop engine, switch headlamps on for 5 minutes (to sink an overvoltage)
- Switch ignition and any electrical loads off and wait 10 minutes (lead-acid chemistry) then press the calibration button
To restore the factory settings connect the device to any 12.6 VDC source and press the calibration button.
LVA has the rigid real-life design (reverse polarity and moisture protections, noise suppression and so on).
The operating temperature range -40 to 100 C (-40 to 212 F) is wide enough but the device is not protected from a dust or water, so for using outside of a normal cab environment pack it in a plastic bag.