While on the subject of meters. I have a Luna-Pro F, and I just inserted a new Lithium 9V battery. The battery test button sends the needle off the scale, like it is getting way too much voltage. Should I not use lithium and go beck to regular alkaline cells like a Duracell or Energizer, or is there an internal regulator in the Luna-Pro which will still give me accurate readings with a strong battery. I prefer to use the long lasting lithium cell if it doesn't throw off the meter.