Must have tool

My Mercedes E350 starts giving me a dash notification "Auxilliary Battery Malfunction" so I checked the battery voltage with a multimeter and gives me 12.79 volts which is a good indication of voltage for 12 volts battery. However, I am not sure if this old battery is sending the required current to the electrical system of my car. So I have decided to order this AIZIC digital battery analyzer tool to deep scan my old battery. To my surprise, it showed me only 20% battery health and some details are not good for the car system. This made me replace my aging aux battery and before installing the new battery, I also tested it with this tool to confirm everything is good, and I was happy with the results. The battery malfunction notification on the car dash never appeared again. I would highly recommend this tool when you are a DIY and you want to save money on future repairs. The kit comes with a carrying case, a manual, and two rolls of paper for printing. The tool is simple and easy to use, but make sure your battery has a charge to make it work properly. I am happy with my purchase.