First, I turned off my LG-D280N and removed battery. Set the multimeter into 20VDC (next is 2VDC) and correctly checked battery pins and checked the voltage.
Next, I checked pins on case, set "diode test mode" and touched two case diode pins (NOT touched battery!).
Then on phone I did the same, but I was scared and after second or less stopped touching this with multimeter cables. When I turned on, I saw on notification bar a symbol like this ( this is not the exact symbol but looks similar with this difference - yellow was transparent, red was white and black was also white)
Did I damaged my battery or the phone?