l bought an Ozito 125 mm 18v cordless grinder about a month ago. I only used it once on and off for about ten minutes to cut thin steel downpipe and it operated great. But l tried to use it yesterday and about 8-10 seconds after l start the grinder it shuts off, l need to turn it off then on again and it keeps doing the same thing. It is practically unusable. It definitely isn't overheated overheated. Is this a common problem?