Battery Monitor #3721

The Innova 3721 Battery and Charging System Monitor is designed to give you peace of mind while driving your vehicle. Easily see when there is an issue with your vehicle’s charging system.

Free shipping | 1-Year Warranty


This product can expose you to chemicals including DiNP, which is known to the State of California to cause cancer.
For more information go to


Simple to Use:

Easily plugs into your vehicle’s cigarette lighter or power receptacle to monitor battery and charging system voltage.

Coverage for Today’s Vehicles:

Designed for 12-volt negative ground systems.

Easy to Read All in One Digital Display:

LCD displays measured voltage with a bar graph to indicate battery charge level.


Quickly identify the battery’s charge status.


Angle the screen and head for easier viewing.

Need more help?
My Battery Monitor does not come on when connected to the cigarette lighter or power receptacle?
If the Battery Monitor does not turn on or display any readings, check the vehicle for blown fuses such as a cigarette lighter, or accessories fuses.
No. The battery monitor will only read the voltage present from the battery and/or the charging system.

The Manufacturer warrants to the original purchaser that this unit is free of defects in materials and workmanship under normal use and maintenance for a period of one (1) year from the date of original purchase. If the unit fails within the one (1) year period, it will be repaired or replaced at the manufacturer's discretion.

No. The battery monitor will only read voltage present from the battery and/or the charging system.