Has anyone hooked up a starting battery volt meter direct to monitor the battery condition? I want to hook up a volt meter direct to monitor my starting battery because most of the electronics run off the starting battery this way I can see the battery condition prior to starting the engine. I see a lot of gauges but cannot find one that has a on-off switch or a momentary switch that has a round hole for installation or a surface mount with a small hole for the wires to go thur the dash panel. Has anyone done this?