The 2018 Ram 2500 uses a 12-volt lead-acid battery system; the diesel model uses two such batteries, while the gas-powered variant uses a single battery.
Battery configurations by engine
Understanding the setup helps when replacing or upgrading. Engine choice largely determines whether the truck uses one battery or a dual-battery system.
Diesel: 6.7L Cummins — dual 12-volt batteries
Most Ram 2500 diesels are equipped with two 12-volt lead-acid batteries to provide ample starting current and electrical support in cold weather. The two batteries are configured to deliver higher total capacity than a single battery.
- Battery configuration: two 12-volt batteries (dual-battery setup).
- Purpose: higher starting power and better accessory support in cold conditions.
- Variations: group size and CCA depend on production year and trim; check the battery label or OEM specs for exact numbers.
When replacing, verify the exact group sizes and CCA ratings as specified by the OEM for your particular vehicle.
Gasoline: 5.7L Hemi (and other gas options) — single 12-volt battery
Gas-powered Ram 2500 models use a single 12-volt lead-acid battery to meet electrical needs. This setup is simpler but still requires a battery with adequate CCA to start the engine and run accessories.
- Battery configuration: single 12-volt battery.
- Typical purpose: supplies power for starting and vehicle electronics.
- Variations: group size and CCA vary by trim and options; confirm with OEM specs.
For replacement, match the OEM-recommended group size and CCA from the battery label or owner's manual.
What to know when replacing or upgrading
Before replacing or upgrading, keep in mind:
- Battery type: most are flooded lead-acid; some builds may use AGM for better performance and longevity.
- Group size: must fit the tray and deliver required electrical load.
- Cold-cranking amps (CCA): ensures reliable starting in cold weather; higher is better within OEM specs.
- Reserve capacity (RC): indicates how long the battery can run essential systems if the alternator isn't charging.
Always reference the owner's manual or the current battery label for the exact specifications for your 2018 Ram 2500.
Summary
In short, the 2018 Ram 2500's battery setup hinges on the engine: the diesel version uses a dual 12-volt system, while the gasoline version uses a single 12-volt battery. Exact group size, CCA, and RC vary by trim and production date, so verify with the vehicle's documentation or a parts supplier when replacing.