Open Circuit Voltage 400V vs 500V?
 

I'll make it short and simple, I am in possession of 3 HID ballasts that have 3 different Open Circuit Voltages and i don't know anything about electrical...

USDM Ap1: OCV 360V
USDM Ap2: OCV 400V
Euro/JDM AP1: OCV 500V

All 3 have the same output voltage and power ratings (85V, 34W)

People upgrade from USDM Ap1 (360V) to USDM Ap2 (400V) all the time without issue, but i don't want to assume 400V --> 500V will be ok.

Is it safe for me to run the 500V HID ballast in my Ap2?

What kind of meter did you use to get those readings?
I'm asking because some cheap meters might show some funky results.
If the rated output is the same I don't think there would be any problems using them though.
The higher OCV would probably just light up the bulbs a bit faster, maybe at the cost on longevity.

Thanks for chiming in. It's actually written on each of the ballasts, i did not measure myself.

I had another friend come over and take a look and he agreed with your comments, so i just installed them. they work fine...we'll see if they blow bulbs prematurely haha