Real-World Comparison: Ranger Super Duty Under-Bonnet Battery vs Ranger In-Tub 150Ah Lithium Mount

The easiest way to understand the difference between under-bonnet and tub-mounted dual battery systems is to look at two real-world setups.

At Pirate Camp Co, we offer two very different approaches: an under-bonnet auxiliary battery mount for the Ford Ranger Super Duty 2025+, and a 150Ah in-tub wheel-arch lithium mount for the Next-Gen Ford Ranger and Raptor 2022+.

These products are designed for different Ranger platforms, so they aren't interchangeable. But they demonstrate the exact decision this guide is about: do you use available space under the bonnet, or build your power system into the tub?

At a Glance

Option 1: Ranger Super Duty Under-Bonnet Auxiliary Battery Mount:

The Ranger Super Duty approach is all about using space that Ford has already made available under the bonnet.

Our Ford Ranger Super Duty 2025+ auxiliary battery mount is purpose-built to use the factory-allocated space for a second battery. The tray is designed to carry a battery up to 120Ah, with a maximum battery weight of 25kg.

For the right build, that's a very clean solution.

You get a permanent auxiliary battery without giving up any space in the tub. The battery stays close to the vehicle's main electrical system, the primary charging cable run is shorter, and you don't need to build a battery box or electrical cabinet into the rear of the vehicle.

That's particularly useful if your Ranger Super Duty is going to work during the week and tour on the weekends.

The tub remains completely available for tools, recovery gear, camping equipment or whatever else the vehicle needs to carry.

I'd choose the under-bonnet setup if:

• You want to keep 100% of your tub space
• Your power requirements are moderate
• You want a clean, permanent system
• You're running the essentials rather than a massive electrical setup
• You prefer a shorter main charging cable run
• Your chosen battery is approved for under-bonnet use

For a fridge, lighting, communications and general touring accessories, this style of system can make a lot of sense.

The biggest consideration is still heat. The battery you choose needs to be suitable for the engine-bay environment, and the complete charging system needs to be designed around that battery.

Option 2: 150 Ah in-Tub Wheel-Arch Lithium mount

The in-tub setup takes a completely different approach.

Instead of using the engine bay, our 150Ah in-tub lithium mount turns the space around the Ranger's wheel arch into a dedicated electrical and storage zone.

This is important because wheel-arch space is often awkward to use efficiently. A conventional battery box can take up valuable floor area, while this setup is designed around the shape of the tub and makes use of space that can otherwise be difficult to organise.

The mount is designed around a 150Ah lithium battery and also provides dedicated locations for a DC-DC charger and fuse mounting. Depending on the exact version and vehicle setup, it can work with factory and selected aftermarket roller shutters while retaining practical use of the tub.

The MOLLE panel and pocket storage add another advantage.

Rather than giving up space purely to the electrical system, you can also use the area to organise smaller touring gear, cables, recovery equipment or other items you want within easy reach.

I'd choose the in-tub setup if:

• You want more battery capacity
• You're building around a 150Ah lithium system
• Most of your electrical accessories are in the rear
• You're running a fridge, Starlink or a larger touring setup
• You want the battery away from engine-bay heat
• You want dedicated space for your DC-DC charger and fuse hardware
• You're happy to use some tub space for the electrical system
• You want the added organisation of MOLLE and pocket storage

For a serious touring Ranger, this can create a very neat all-in-one power zone.

Which one would we choose?

If I was setting up a Ranger Super Duty as a work vehicle that also heads away on weekends, I'd seriously consider the under-bonnet mount. Keeping the entire tub free is a massive advantage, and for a straightforward touring system, up to 120Ah of correctly specified auxiliary battery capacity may be more than enough.

If I was building a Next-Gen Ranger for longer trips, running a fridge every day, powering Starlink and carrying more electrical gear, I'd lean towards the 150Ah in-tub setup.

Not just because of the extra battery capacity.

I'd choose it because the whole electrical system can live closer to the equipment it's powering. The battery, DC-DC charger and fuse hardware can be organised into one area, while the MOLLE panel and pocket storage help make use of the same space.

That's the real difference between these two setups.

The under-bonnet mount prioritises keeping your cargo space completely free.

The in-tub mount prioritises battery capacity, electrical integration and proximity to your touring accessories.

Neither approach is automatically better.

The best one is the setup that solves the bigger problem in your build.

If you're constantly fighting for tub space, go under the bonnet where the vehicle and battery allow it.

If you're constantly fighting for power capacity and trying to organise a larger touring electrical system, using the wheel-arch area in the tub can be the smarter move.