I haven't noticed any changes in performance since then. I use it as a grinder and sometimes for cleaning. First, I took a screwdriver complete with a charger and 2 batteries for 5A, and then a bare angle grinder carcass to it, because why buy and carry 2 suitcases, 2 chargers and 4 batteries., and money is stressful. At first I wanted to take a screwdriver with 2A batteries, the sellers advised well, they said that they would last for a couple of minutes on the angle grinder. 5A batteries last an average of about 20 minutes of operation, and the mode and load have almost no effect on the operating time, I tried cutting with a disk, stripping and just buzzing at idle with frequent replacement of cut parts, I did not notice the difference. I take cutting discs 1-1.2 mm thick. It is very cool to work with no string and the presence of electricity, and at times it is necessary for work. Completely satisfied with the purchase!