It was only built with one battery. It is under the carpet in the cargo area. If it has two It is a later addition.
For the Magnum SXT it only has one battery and it is in the rear compartment next to the spare tire.
The question assumes there are 2 batteries, when in reality there are not 2 batteries. It has only one and it is located in the trunk near the spare tire.
The 2005 and up Dodge Magnum has an electric pump on the driver side and a siphon pump on the passenger side. Both are accessible from under the rear seat.
1-2-3-4-5-6
Purge solenoid.
Mazda Miata, Chevrolet Corvette, just to name 2. There are many others. 2005 and later Dodge chargers, Dodge Magnums, and Chrysler 300's
V6, 1-2-3-4-5-6 V8, 1-8-4-3-6-5-7-2
Bank one is the side that includes cylinder number one. Bank two is the opposite side.
2 carpros.com/car
How do I get my magnum remote to work after I changed the battery in it and the doors are locked
2005 Dodge neon has a rear adjustment for TOE only
Most diesels have 2 batteries to supply the necessary cold cranking amps Two little batteries are cheaper then one big battery