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INNOVA 3721 Battery and Charging System Monitor

12 Volt Negative Ground Systems, Lcd Displays, Battery And Charging System Voltage, Battery Charge Level

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Created with Raphaël
BVR Rating 1,620 reviews


  • LCD displays measured voltage with a bar graph to indicate battery charge level
  • Built-in head pivots for easy viewing and angle adjustment
  • Easily plugs into vehicles cigarette lighter to monitor battery and charging system voltage


  • May stop working after a few readings

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Analysis of 1k+ reviews for INNOVA 3721 Battery and Charging System Monitor


BestViewsReviews analyzed 11,055 reviews for 31 products in the Battery Testers category.


We analyzed a total of 1,620 reviews for this product out of which, 40 reviews were received in the last 6 months.


The analysis indicates that around 81% reviews were positive while around 16% of reviews had negative sentiment.

BestViewsReviews Ranking and Score for INNOVA 3721 Battery and Charging System Monitor


This product received a total score of 9.74 out of 10, based on review sentiments and user opinions related to 10 features:

  • Size
  • Accuracy
  • Value for money
  • Overall performance
  • Build quality
  • Design
  • Portability
  • Customer support
  • Easy to read
  • Easy to use
  • Users of this product said

    It gave me the information I needed to get a battery fixed quickly so I didn't have to wait for service in the cold.

    I got going after a cold night and a third jump start but when I plug in the device, it says that my battery is not charging and I have to turn on the heat for 15 minutes.

    This product does a great job but there is a slight delay and I would highly recommend it for anyone who is interested.

    It worked as advertised and it was easy to read all of the readings I matched with myvoltmeter.

    It is very easy to use and read, and it is accurate when I take my car to auto zone.

    Question & Answers


    Is it possible to leave it plugged in for 1-2 days?


    I have to be careful not to leave other accessories plugged in while the truck is off, because this meter would not be a problem left plugged in for a few days.


    What is the accuracy of this device measured against a regular volt meter?


    It's within a couple of tenths of avolt between the alternator voltage and the power port voltage, but even that could be accounted for by voltage drop in the vehicle wiring.


    What is the significance of the battery icon at the top of the display?


    The battery icon at the top of the display tells you when you're testing the battery.


    Is there a current draw of this device, either in Amps or in Watts?


    I leave the car plugged in, but I do watch the numbers climb as the battery gets charged.


    I connected this unit and it lights up, flashes all lights, goes to green, and then just shows a 1 in the far left position. Anyone know why?


    If your battery voltage is too low to operate the meter, you should send it back for a new one.

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