[Paul T]

ok, I am no electrician at all, but I broke out the trusty digital multimeter the other day to check an aging car battery and ran into a dilemma.

A quick check of the voltage and...wtf, 16-17 volts?! That doesn't seem right! So, I switch to AC and check the house outlets for comparison and I get...170! What the hell. Now, knowing nothing, I just figured my multimeter was fried (it's old and cheap), but a quick google search has me believing I might be measuring "peak" as opposed to "rms" voltage? Does this make sense to anyone? I have no idea how I may have changed that setting if so and can't find any reference to it anywhere on the meter. Also, it seems the peak/rms differences only apply to ac voltage, so why the odd reading on the car battery (checked a couple and same thing)?

So, anyway, I go out and buy a nice new digital meter thinking that is the problem. Get home, check the car batt and get 12.5v - ok all is good. But like an idiot I try and check the ac voltage again (and yes I changed to ac voltage) and get a reading of 170 again! Then I go back to the battery and now it's reading 17! Am I somehow frying my meters here? Am I just an idiot? Electrical issues have always been my nemesis....