Truck rattles as it slows down and at idles

My 2004 Toyota Tacoma V6 2 wheel drive rattles when we slow down, drive slowly (like up the drive way), and are at a stand still. It does not rattle when the truck is in neutral.

What is the deal? Thanks for the help!

I suspect a heat shield for the exhaust system. Maybe the engine doesn’t vibrate strongly enough revving in neutral to set it off.

So I looked under the hood and found that the Battery had become dislodged pressing against the exhaust manifold, which would explain the rattle.