I support the "Get a meter and measure" suggestion.. The reason is this.
I'm cross trained in electrical and electronics.
As someone up-thread said.. IN Electrical (120/240 and more) Black is hot, white is neutral, which is bonded to ground at the service box (first box past the meter)
IN Electonics, including automotive, Black is ground, as it should be (Ok, that's a

)
Most RV's are wired by electricans, not electronics techincians like me
So I see a lot of white wires on the ground bus in my 12 volt panel
So measure, just to be sure
And on the battery, Paint or nail polish the wires hooked to the POSITIVE Terminal RED, don't be afraid to overpaint the battery itself
Black on the Negative end of the battery bank as well
That way if you ever have to re-connect... You will know which wire goes where