Voltminder Battery Alarm / Monitor
Here is a simple and inexpensive way to monitor any 12V battery. Plug it in to any 12V power source, set the desired minimum voltage for the alarm, and off you go! It will automatically alert you when your vehicle's battery is depleted and needs recharging with a loud audible warning. It also features instant voltage read-out and a back-lit LCD for night use.
This VoltMinder can also be calibrated for use with any system voltage of up to 50V, if you happen to need something like that.
The VoltMinder performs two very critical functions:
#1) Alerts the operator that the battery is approaching a voltage that will not be sufficient for the engine to start, to operate 12V accessories, or at a voltage that could do permanent damage to the battery itself.
#2) Alerts the operator that the battery is not charging while the engine is in operation.
The actual "real time" voltage of the battery is displayed via a digital readout on VoltMinder. An audible tone will sound when the battery voltage is reduced to a level that is designated by the operator. This warning voltage level can be set anywhere between 10.5 and 50 volts DC.
VoltMinder dimensions: 4.1" X 2.8" x 1.0" and comes with a 6-ft cord that plugs into your vehicle's power outlet (cigarette lighter), or it can be dash-/wall-mounted with the included screws if you wish to permanently install the unit and hardwire it to your system. Generic instructions for installation are included. If hardwiring, we recommend connecting the leads directly to the battery you wish to monitor for the most accurate reading.
NOTE: When in operation, the unit draws 28 milliamps (mA) of current (32mA when alarm is sounding). If you plan on parking your van for more than a couple of weeks, we recommend unpluging the unit to prevent it from draining your battery (because... well, that would be silly, wouldn't it?).