AUTO METER RC300 Professional Handheld SLA Battery Tester - 12V/24V Lead Acid Battery Voltage Analyzer for Cars, Trucks, Motorcycles & Marine Use

Works great have purchased several different versions.I've used it before. A replacement for one stolen.Product requires a brand new battery to perform accurate test on old batteries. This was confirmed with the manufacturer. But it is not stated as such in the user manual.The readings it produced without first testing a new battery indicated that my 6 year old batteries had more capacity than they were ever designed to have. And not just a little more, they are 28Ah and this tester tested them to be 38Ah.The manufacturer claims that the tester is a "professionally accurate reserve capacity battery load tester" "quick and accurate results". But it does not provide accurate tests without having a new battery to test an old battery.This is an amazing product I have been using them for 10 years the company is awesome to deal with and they're very good about any warranty issues I use my tester everyday multiple times I run at e-bike business and this is the only tester on the market that I could find that test for amp hours and state of charge and voltage if you put a regular load tester on these type of batteries the small 12 volt 20 amp hour batteries you will harm the electrodes inside this tester does not do that it is a digital pulse load they are extremely expensive but you can't really get them anywhere else at any type of quality like that and extremely simple to useGreat Tester works well and has a proven track record of being reliable. Just being picky but only thing that I do not like is the size as I find it a bit on the large side.