**CARTMAN 12V Car Battery and Alternator Tester - Digital Battery Condition & Charging System Analyzer with LED Indicator - Perfect for DIY Auto Repair, Roadside Emergencies & Vehicle Maintenance**

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.