In most 2018 Compass models, there isn’t a separate auxiliary battery in the way some SUVs carry a second 12V unit. The vehicle relies on a single 12V battery for starting and standard electrical loads. If your model has the optional eTorque mild-hybrid system, there is a separate 48V battery component that powers the hybrid functions, but that is not a conventional auxiliary 12V battery and is not sized like a typical automotive auxiliary battery. For the exact size, check the battery label or the owner’s manual for your specific build.
What counts as the auxiliary battery in this vehicle
Here’s a practical breakdown for owners and prospective buyers who want to understand the battery setup.
- The standard 2018 Jeep Compass uses a 12V starting/auxiliary battery for most electrical loads. The exact group size varies by market and trim, commonly found in the Group 48 (H6) or Group 51R families in recent FCA vehicles.
- On models equipped with the eTorque 48V mild-hybrid system, there is a separate 48V energy storage component. It is not a traditional 12V auxiliary battery and is not sized or replaced in the same way as the 12V battery.
- Exact battery specifications (group size, CCA, and reserve capacity) can vary by market, trim, and production year. The best source is the battery label on the top of the installed unit or the owner’s manual for your vehicle’s configuration.
In short, the “auxiliary battery” label doesn’t apply to the standard Compass; the main 12V battery handles conventional loads, and the 48V pack in eTorque-equipped models supplies the hybrid system rather than a separate 12V spare power source.
Where to find the exact size for your vehicle
Because battery sizing can vary by market and trim, verify with official sources or your dealer. Useful steps include checking the battery label for the “Group Size” and CCA rating, inspecting the owner’s manual, or using the vehicle’s VIN to get the exact replacement part from Mopar/Chrysler catalogs.
Bottom line
Most 2018 Jeep Compass models do not have a conventional auxiliary battery. They rely on a single 12V battery, with some eTorque-equipped versions using a separate 48V hybrid battery as part of the mild-hybrid system. For a precise size, refer to the battery label or the owner’s manual for your exact build.
Summary
In the 2018 Jeep Compass, the standard setup centers on one 12V battery with possible inclusion of a 48V eTorque hybrid battery in certain configurations. The term “auxiliary battery” isn’t generally used for these vehicles, and exact group sizes vary by market. Always check the battery label or official documentation for your specific model.
What happens if the auxiliary battery dies?
It's unlikely that you'll notice any drivability problems with your vehicle once the auxiliary battery fails. The worst thing that could happen is that you won't be able to use the electrical components that get voltage from the auxiliary battery.
Is there an auxiliary battery in a 2018 Jeep Compass?
So we're going to do that and the tools that we need is a power gun extension a 10 mm socket.
What is the second battery in a Jeep Compass called?
Start stop. And what that does is when you pull up to a traffic light or stop sign from time to time it will actually cut the engine off but as soon as you let off on the brake pedal.
What size battery does a 2018 Jeep Compass use?
Super Start Economy Standard Flooded Top Post Battery Group Size 48 H6 615 CCA 95 Minute RC - 48ECO.