Cadillac 2010 DTS Owner's Manual page 358

You will not see the battery of your vehicle under
the hood. It is located under the rear passenger's
seat. You will not need to access the battery
for jump starting. The remote terminals are for
that purpose.
WARNING:
{
An electric fan can start up even when the engine
is not running and can injure you. Keep hands,
clothing and tools away from any underhood
electric fan.
6-38
WARNING:
{
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use a flashlight if
you need more light.
Be sure the battery has enough water. You do not
need to add water to the battery installed in your
new vehicle. But if a battery has filler caps, be
sure the right amount of fluid is there. If it is low,
add water to take care of that first. If you do not,
explosive gas could be present.
Battery fluid contains acid that can burn you. Do
not get it on you. If you accidentally get it in your
eyes or on your skin, flush the place with water
and get medical help immediately.