CARTMAN12V Car Battery Tester, 100-2000 CCA Load Tester Automotive Alternator Tester Digital Auto Battery Analyzer Charging Cranking System Tester for Car Truck Marine Motorcycle SUV Boat

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.

I was having some issues with a car battery and then my mower battery all within a week. Mentioned my problems to a friend and he recommended this tester. It is a simple tester. Not a high tech tester like at an auto parts store or a shop, but a fair starter for a homeowner or DIY person. Low cost and just enough information to help you make an informed decision on what Might be wrong or point you to the next step in solving your problem. Good purchase. I keep it in my truck tool box.

This little device works very well to check a 4-6 cylinder battery to see if it is charged or can be chaeged.,with car offIt can also check alternator to see if it is at proper amps or not(just a good or not good) with card runming.You can't beat the price for this kind of help!

I have a car where the battery isn't holding a charge when the car is off. It only has about 20K miles on it. I figured either the battery was bad or the alternator possibly has a short, so I got this thing. First the cable is barely long enough to reach the terminals on my car. My car has the battery in the back under the floorboards of the trunk. Under the hood there is a (+) terminal where you'd expect a battery to be and the (-) terminal about 10-12 inches away on the firewall. I had to tear the cable black/red down the middle to the base of the device to make it be able to reach. Then the clips were barely big enough to get on the terminals which aren't that big.With my car engine off the bottom most light (OK) was red and none of the low/mid/full charge lights were on. The minimal instructions are rather confusing. It seems this either means the battery is dead or able to be charged. I started the car and it had enough juice to start up without being jumped so it couldn't have been completely dead. Once the engine was on, the "OK" turned off and the "full" light turned on. So now my battery went from dead to full (which I know it wasn't cause the care barely started). For the alternator lights it flickered between good and fault before settling on fault. It says you should accelerate to 2000 rpm to do this check so I did that but got the same results. So if this is to be believed I need a new alternator and not battery. If it was the battery I could change it myself; alternator I'll have to bring it somewhere. Guess I'll see when I take it in what is actually wrong with it; not sure this really helped me figure that out.

Works like a charm, so glad I have this now.I own a 1800watt amp that powers 2 14” subwoofers, which I installed. I also own a 1998 which has an old stock head unit(without a remote cable input). This means I had to bypass any remote control (whether the amp turns on and off with the ignition of the car) by connecting directly to the power supply and installing a toggle switch near the driver side. If your brain isn’t as fried as my battery gets when I forget to turn the toggle switch off for days, then you get the idea. I’ve gone through too many batteries and been late to work too many times just because I wanted to bump the night before.Anyways, now that I have this small tester, I can evaluate whether or not my alternator is bad, if the battery is truly dead or if it holds a charge.Thank you so much and stay full!