usb remote batteries wrong way. what would happen?

[ssjchar]

I bought a flashlight that uses 3 1.2v batteries to use for for a usb remote on my s3is.  i'm not sure which way i should put the batteries.  the batteries just drop into the housing.  what would happen if i put the batteries in the wrong way?  would it break my camera or anything like that?

[BB]

None of the schematics I saw had it--but you should put a ~100-300 Ohm resistor in series with the battery/regulator output to the data line... Even if it is shorted, the battery is to high of voltage (within reason), or any other major mess-up--the series resistor should limit the power low enough that the USB circuitry will not be damaged.

-Bill