CARTMAN 12V Car Battery Alternator Tester, Test Battery Condition & Alternator Charging, LED Indication

I frequently test car batteries at our small dealership prior to charging them with a battery charger. I was looking for a cheap and easy method to quickly test battery charge levels and potential alternator issues. The schumacher battery charger I have has a test/charge meter but it is a complete joke. I've been using this little tester for a few days now and it works great. I've found it to be fairly accurate for a general reading.There is another unit similar to this one by Pulse Tech but I decided to jump on this one because of the lower price and I like that this one comes with high quality clamps. The others in this price range only have needle/pointy type receptacles that are less convenient when you need your hands to be free. I also don't like coiled type cords because I've had bad luck with them beginning to fray and lose connection.This tester doesn't tell you the percentage of the battery level as seen in the picture- only a low, mid and full. I'm assuming that low is ~25% middle is ~50% and full is ~75% charge and above. Thats my only gripe with it- the instructions dont tell you what the levels are and I'm assuming a charge of 72% for example would light up as "middle". The instructions are poorly written in "Engrish", they could be a little clearer.For alternator testing, I tested a Lexus SC400 with a brand new battery that was known to have a bad alternator. You rev the car up to 2000+ rpm and connect the clamps to your battery. The tester showed the alternator as faulty so I can confirm it works. I obviously wouldnt put my complete trust in this unit to diagnose everything since it's usually not as cut and dry, but it will lead you in the right direction. For the price, you can't go wrong. Build quality is decent and its no frills.

For about 2 years now, the ECO mode on my 2016 Mercedes E350 was not engaging. After looking around online, I thought it might have been the auxiliary battery in the trunk and tried replacing that, but to no avail. I started to have the feeling that my main battery may actually be the cause, and only because it shuttered a bit on a very cold morning a couple of months ago while trying to start the vehicle. I purchased this to be able to more accurately check the battery, thinking the cranking amps had declined over the years on a battery that was about 6 years old already. Sure enough, the battery showed to be bad. When started, the unit was able to show the alternator was charging just fine as well. I replaced the battery with a new one, and the ECO mode works perfectly now. Problem solved!Unit is very easy to use and self explanatory. Good way to see if your battery needs to be replaced or alternator not charging correctly.

It's inexpensive so wasn't expecting a $$$ machine but it could stand to be a little heavier so it would lay flat while trying to attach the clasps which are too small to go over the battery top-posts. It works as advertised; I needed a tester which would show if the alternator's internal regulator was malfunctioning since both of the mechanics who tested my alternator said it working and was charging my battery (used their $$$ equipment) but the battery would not stay charged even after they replaced my battery twice. This registered "fault" for my alternator when I first started my car but after driving and retesting it registered "good" so then I knew that the internal regulator was working intermittently and I replaced it. Without this little inexpensive tester I would still be fighting this problem. This did not get hot to the touch or make any kind of smell as other products' descriptions warmed of. It was probably only 1-2 min.s that I had to have it attached to the battery to check my alternator (hook it up, get in the car, start it, and rev the motor up to 2000rpms, keep the car running, get out and look under the hood at the tester's lights and then turn the car off in order to test the battery). It was more than worth the little paid for this.

I own a very exotic car, the type where it costs almost 300 dollars to have the oil changed, last week it started to show me code numbers which meant it was having an issue. I knew the shop would charge me a few hundred dollars just to diagnose her so I decided to try and figure it out myself even with no background in auto mechanics. After researching on the internet I discovered that the issue lied within the boundaries of the alternator, battery, wiring or a fuse. I purchased this item due to the simplicity of how it works and with it I was able to remove the alternator and battery as a possible issue, in the end it was a fuse and I was able to repair the problem for just a few dollars. So to the developer of this item I give you my thanks