12V Battery Reading 17.4V

Well what I would first do is forget about self-testing or whatever it is you're doing with the car get out of test meter or take your car to a good part store like O'Reilly's or AutoZone or Menards and they'll walk out with this $20,000 handheld tester and they'll tell you what your battery is telling them 17.8 volts out of a 12 volt battery is quite a stretch or something's being read incorrectly and I would say get a second party meter on your 12 volt system and see what they say If anything when your car is ready you should be seeing somewhere near 14.5 volts and when the cars at rest for 20 minutes or more you should be seeing more like 12 volts 12.5 somewhere in that range but not below 12 It's a 12 volt system 17 volts at rest the car not ready I think something's being misread or something along those lines. Let this part store run a test on your 12 volt system and tell you you've got 17 volts I think not.

 

I am ASSuming that you have a typo for the OFF voltage. Did you mean 12.2-12.4V? If it was not a typo, use a volt meter to test the battery and see what you get.

The ON reading of 14.6V is normal when the car is in Ready Mode.

 

a lot of automakers are going to 18v starting systems

 

They should just go right up to 48 volts keeping it low voltage by being under 50 volt. My buddy who's in the automotive electronic quite a bit so they just wasting everybody's time same with cordless appliances all of that stuff should be up to like 48 volt systems forget this 20 volt dewalt and 16 volt cordless vacuum cleaners and 12 volt automotive vacuum cleaners all that 48 volts just to keep it under 50 so it's considered low voltage but at least those machines will have good power and all of that .