Amazon.com: Customer Reviews: INNOVA 3721 Battery and Charging System Monitor
Your Garage Best Books of the Month Amazon Fashion Learn more Discover it $5 Albums Fire TV Stick Subscribe & Save Patriotic Picks Shop-by-Room Amazon Cash Back Offer WienerDog WienerDog WienerDog  Amazon Echo  Echo Dot  Amazon Tap  Echo Dot  Amazon Tap  Amazon Echo Starting at $49.99 All-New Kindle Oasis UniOrlando Best Camping & Hiking Gear in Outdoors STEM

Price:$9.98+ Free shipping with Amazon Prime
Your rating(Clear)Rate this item


There was a problem filtering reviews right now. Please try again later.

Showing 1-10 of 34 reviews(1 star). Show all reviews
on November 30, 2012
I only used this for about a month and a half, it is busted already. I used it in my 4x4 and the car. It was working okay and one day suddenly stopped working!! I have tried it in both the 4x4 and the car but no luck. As far as I can see there are no batteries or anything to be replaced so I guess I will have to throw it in the bin! I am in Melbourne and it is not worth trying to return this item.
0Comment|9 people found this helpful. Was this review helpful to you?YesNoReport abuse
on December 30, 2012
We have had repetitive charging issues and this tool has been a great asset to help my wife determine if the charging system is working (via led's).
Update: After one month this tool has become completely worthless. Different readings each time you move it.
0Comment|6 people found this helpful. Was this review helpful to you?YesNoReport abuse
on February 1, 2012
I followed the instruction to test the batteries in my 2012 Honda Odyssey and 2008 Honda CRV. In both cases, when measuring the "state of charge," the meter kept telling me that my batteries had only about 12 v of power, and the red light further indicated that the battery was low in charge. Not sure what this meant (my Odyssey is less than 1 mon old and the CRV just got a new battery last Oct), I took the Odyssey to the dealer, and they measured it and told me that my battery was in good working conditions. The Odyssey has a built-in "low charge" warning system which never came on so it further suggested that the meter's reading is wrong. Is the meter defective? I assume so so I have returned it. It is also possible that in some cars, the auxiliary power outlets do not output the full 12.6 v so one cannot use this to measure the actual voltage in the battery. Either way, before you buy this, be aware of this issue and talk to your service manager first.
11 comment|8 people found this helpful. Was this review helpful to you?YesNoReport abuse
on June 18, 2008
The numbers are clear even at night however after just 5 days of operation, the green back light died so I can't see anything at night. The meter still works so I can only use it during the day. I called their tech support and said that they'll replace this one if I return the faulty unit, however, I have to pay for the shipping! Since their product failed, I believe that they should be the one handling the return cost. Returning would already cost half the price I paid for this item.
55 comments|27 people found this helpful. Was this review helpful to you?YesNoReport abuse
on February 25, 2016
First one was DOA basically.

Acted crazy with light going from green/red and back even though the voltage was constant. The "cycle" light was always on and so was the battery. I think this must have been infected by a virus from my car or something. Amazon is sending me a replacement (gotta love amazon!!)

Update:
Well, amazon did send me another one. Another DOA. This one said my car voltage was 7.2v and had a red light. But wow! I started my car on 7.2v. I have an amazing car. So who needs this thing. (Sent it back for good this time.)

First picture in RV shows dead but generator started on "dead" battery.
Second pictures shows el-cheapo harbor freight. Left shows generator green. And battery is also fully green.
Third picture shows same situation with car. The car started also.
Last is video (very poorly done, almost embarrassingly so).

I've got vehicles that breaks the laws of physics. How kewl is that?
review image review image review image
0Comment|Was this review helpful to you?YesNoReport abuse
on April 11, 2011
When I plug in the first time, the signal light changed from read to green or yellow. I was very confused and wonder whether there is electrical problme of my car. I brouhg my car to two different garage for check up. After several hours of waiting, there is no problme with my car at all. How much can you trust this little cheap but convenient device?
0Comment|5 people found this helpful. Was this review helpful to you?YesNoReport abuse
on January 18, 2013
This item isn't worth buying! It does not show the correct voltage! I have removed it and reinstalled it and each time the voltage is different. The range is 12.8 to 14.5 volts. I have check the battery voltage with my Greenlee volt meter and it consistently reads 13.8 - 13.9 volts.
For some strange reason when I rated it with one star, it automatically jumped to four stars. Will try one star again.
11 comment|4 people found this helpful. Was this review helpful to you?YesNoReport abuse
on January 31, 2012
I tried to plug it into two cars. It did not work and could not able to check battery charge level when cars not running. 13.68 on the screen all the time. I'll do some research to buy a different one.
0Comment|5 people found this helpful. Was this review helpful to you?YesNoReport abuse
on December 4, 2013
The concept is great and it worked beautifully for about 4 week. Now it indicated a typical auto battery puts out 18 volts wihtout the engine running. I tried on 2 different vehicles.
0Comment|5 people found this helpful. Was this review helpful to you?YesNoReport abuse
on December 9, 2008
Try unit out when I first bought it. Everything seem ok. Did not use for a month and then when I try it again, background light no longer works. Only used it once prior to light burning out. Too late to return unit with incurring shipping cost.
11 comment|15 people found this helpful. Was this review helpful to you?YesNoReport abuse

Questions? Get fast answers from reviewers

Please make sure that you've entered a valid question. You can edit your question or post anyway.
Please enter a question.
See all 70 answered questions


Send us feedback

How can we make Amazon Customer Reviews better for you?
Let us know here.