Methods of Checking Cross-Compatability of Dell Peripherals

I am trying to determine if I can use the battery from my Latitude C610 in a C840. I do not have physical access to the C840. In the past I have experienced Dell peripherals that closely match the notebook style and bay type/size, but fine differences not always visible to the naked-eye makes them not fit the particular model. I have seen this on a variety of older Latitude Models.

Is there perhaps something off the laptops' serial number or some terminology that will tell me if its going to match?

(No, Bob, you cant reply.)

Thanks.

-Dave