Works well - the tester we had for several years ...
937409
Works well - the tester we had for several years broke and we use quite a few batteries in our home for candles, etc. and needed another one - this works very well.
3109097
This replaces an older Battery tester that the leads came off of. So far works just fine. The slider is a bit hard to manipulate with a battery in the holder area.
906701
Good product - this was a replacement of one I had for a number of years
3902224
I bought this tester for my son. He really likes it. This little tester works great, very easy to use, no batteries required and very good price.
4494213
"Toaster" These have not changed much since they were first offered many years ago. There are expensive, electronic, "battery analyzers" available now, but the reviews are mixed on those, and load testers (like this model) are as simple and reliable as it gets. This model is not really made for the large Diesel engine starting batteries. Works well on most automobiles, (probably not a Tesla).
2077138
This unit worked as expected. I had installed the volt/ammeter in place of the analog ammeter in a Schumacher model SE-1010-2 battery charger. After gutting out the old ammeter and a little judicious use of a flat file, I was able to insert the display case into the ammeter housing. Since this charger only puts out 10-15 amps max, I removed the 8mm connector bolts from the ammeter shunt bar and used the 2 smaller screws to make the electrical connections after gluing the shunt to a block of wood and glued the assembly to the charger case front.

The connection diagrams that come with the unit are quite usable and clear (Of course I've been an electronics technician for over 45 years). There are adjustments on the display to set the voltage and current being displayed, but I found the readings to be fairly close to the measurements I made with my test equipment... Your mileage may vary.
4641051
Our last one went a year past its expiration date before starting to give false readings and alarms it has worked well and we wouldn't have any other it has been reliable and when tested worked and the one time it actually had to work it did when because a faulty dryer vent the gas dryer was leaking carbon monoxide into basement.
2395058
Great tester for the price. When you turn it on the reading jumps all over but as soon as it is immersed in the test liquid it stabilizes. Seems to hold its calibration pretty well; I check it about once a month and it is only off by a tenth or so. Comes with dry chemicals that you mix with distilled water to make the calibration solutions. The adjustment screw is very sensitive so it sometimes takes a couple of tries to get it set correctly. I would recommend this tester to a friend.
4759505
Tester is very compact and feels rugged (I have no dropped it to test it for sure).
Can fit into a pocket and is well shaped for use.

Function is very basic, push into outlet and look at the lights.  It does have a button to test GFCI also.

The legend of what the lights mean is on both sides of the tester (which is nice).

I'm quite happy with it.  Went around testing every outlet in my house - all were OK, but still glad I checked.
3894956
I am really happy that I got this cheap little battery tester.  It is really simple to use.  In one hand hold a battery, then in the other hand hold the tester and touch the top terminal and with your thumb easily slide the red slider to touch the other and it should easily move the needle if it isn't very dead.  The instructions say to only test it as briefly as possible because it will run the battery down.  So by both instructions and my experience you just hold it for a second and the needle jumps to green for good batteries and there shouldn't be much question about it.  Sometimes you don't make a good connection and it doesn't move.  So just check your contact points and try it again and it should work on the 2nd try if you need to try again.  If still doesn't work, the batter is probably very dead.

This isn't a load-bearing test or anything really sophisticated that you might find with more expensive tests that can apply a load.  If you do some research, you'll find that multi-meters are supposedly a great tester for batteries but you have to interpret the results.  It is far more convenient to use this little tester to quickly check something.  I moved my multi-meter to my battery storage location so I might use it if it was more accessible.  But even so, it is more of a pain to turn on, configure, connect the probes which is a lot more ackward, and you still have to interpret the output yourself.  This is so much easier.  Maybe if I had a battery in question that needed more inspection I would follow this simle tester with more robust testing if I needed to.

The other day I received a new electronic device that didn't work when I put in the single AA battery required.  I thought it was broken, and sure enough this said it was a dead battery and a new battery worked.  Of course you can always just try another battery and if that works assume the one that didn't work was dead.  Another old simple alternative is to just get a flaslight that takes the size battery you need and see how bright or dim the light it with the battery you want to test.  It is a good old way to test batteries.  However that will only work with incandescent bulbs which are disappearing, replaced by newer led-based flashlights.
1368646
This tool allows you to use a standard meter to test 30, 300, and 3000 amp sources without blowing the fuse in your tester unit. You need to have a separate multimeter to use this. It does not come with one.  The flexibility is great.  It's easy to use by unscrewing one side and putting it around whatever you need to test.  The flash light is a nice addition.  The price of this item is $20 cheaper at FLIRdirect.com.  You can also order with bluetooth for about $50 more here on amazon.  If you need this item, I would choose one of the choices listed above.

If I find a professional, who can use the higher amp test, I will update my feedback.

This item works as described.
3283119
I used to be a mechanic and have used testers  like these before  mainly Midtronics which are very  expensive. This tester does the exact same thing and it is very easy to use. Saves time and money when you are diagnosing starting and charging systems
4469507
the tester is amost impossable use ,& that was what i waS BUYING IT FOR.
I GUESS I MUST LOOK FOR ANOTHER TYPE OF TESTER
IF YOUR BUYING JUST FOR STORAGE IGUESS IT'S OK
2537671
Circuit tester works well I like how well you can see it ( the light ) in the daylight. I really like the coiled cord on it,makes it so much easier to check any circuits. Purchased this one because it looks like it built very good (and it looks like my old circuit tester but without the coiled cord that Ive had for 30-40 years)
2033481
I like that the tester is always on and ready to go.  Don't have to turn it on before testing.
4503016
My old tester just had a red, yellow, green light. This tester at least gives you a more specific charge so when you did into your battery drawer for a couple of batteries, you can make sure the batteries you put in whatever device match in charge if not brand.
2049144
This product is simple to use; and it works fine for determining whether or not a battery is good or bad.  The product could be improved by making a curved indentation in the area where the battery is placed for testing.  With the current straight design, it can be difficult to keep the battery in place; hence I can only justify givings this product a 4-star rating.  This rating is based solely on the product quality, and not the delivery time.

If you're not in a hurry to receive it, this tester is a good value.  I ordered three of them (i.e. intending to give two of them as Christmas stocking stuffer gifts).  My order was placed on December 5th; but I didn't receive them until the 17th of January.  Admittedly, Amazon's description does show a long estimated delivery time; but I failed to notice it.  ("My Bad" for not paying closer attention to this!)  The testers were shipped directly from China; so returning the two extra ones isn't an option.  The return postage would cost me more than I paid for the testers.