Silver thing over battery cable

Jennifer, are you talking about the connector that the battery cable plugs into? I'm not sure what else would constitute a "silver thing" in there. In the picture below, the arrow points to what I'm referring to.

If it is the connector, it can be replaced, but requires moderately experienced soldering skills; a competent repair shop should be able to replace it fairly easily if it's something you don't feel comfortable attempting.

If that isn't the part you're talking about, best thing to do would be to add a picture of it to your question so we can see what you're talking about.

Adding images to an existing question - iFixit Repair Guide