Mike

The formula at the Landiss site is correct!

I just did a key-on test on my X11/3 to confirm the formula :

Battery voltage : 13.7V

Pin 3 voltage : 4V

Ratio : (4/13.7) x 100 = 29% (???)

If you use the formula :

[1 - (4/13.7)] x 100 = 70%

which is correct coz it's a federal car!

So the formula is correct!

Thanks for the heads-up, Mike.