I am working on a small project currently -- I recondition hybrid car battery packs with a grid charging system, and I am working on a voltage sensing circuit that's monitored and available via a network. The voltage sensor I currently have is only capable of measuring 250VDC, and some battery packs exceed this.
I was going to make a simple voltage divider with like-sized resistors to just cut the voltage in half, which would bring me well within the 250V range. The voltage sensor is obviously an extremely low load, so what value resistors would I need for this? And what wattage rating should the resistors have?
Edit: here is the link to the voltage sensor I plan on using. http://www.yoctopuce.com/EN/products/usb-electrical-sensors/yocto-volt
Also, maybe I'm thinking incorrectly, but if I connect two resistors in series(and use the center tap as the half voltage) to a 250vdc battery, aren't the resistors just going to blow? I really feel like I should know this :/