2024 Jeep Wrangler 4xe Power Box Review: A Portable Power Bank You Can Drive
We put Jeep’s new Off-Board Power Panel to the test with lots of different electrical loads to uncover its qualities and quirks.
After three years of Jeep Wrangler 4xe plug-in hybrid production, Jeep is at long last allowing owners to use the big battery onboard to directly power tools and overlanding campsite essentials like electric chainsaws, coffee makers, electric coolers, and air-mattress pumps. Behold the Power Box (Pro tip: It's exclusively referred to as the "Off-Board Power Panel" in the owner's manual). It plugs into the 4xe's J1772 charging port and provides two 120-volt duplex outlets, each of which can support 15 amps' worth of current draw. We plugged a lot of stuff into the Power Box, scoured the owner forums, and are ready to answer some questions, provide some caveats, and generally demystify the Power Box.
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Which Jeeps Get the Power Box?
The Power Box was originally supposed to launch on all 2024 Wrangler 4xe models, but supply-chain woes forced a $250 delete option (code GF8) on a lot of them. Today it comes standard on Sahara, Rubicon, and High Altitude 4xe models. The Jeep Grand Cherokee 4xe is not compatible with the Power Box at this time.
How Does the Power Box Work?
Simply plug it into the charging port, press the AC Power button on the Power Box, key the ignition, and wait a moment for the box and your Jeep to communicate. You can hear a click under the hood when this happens, at which point both the Vehicle and Power lamps on the box illuminate solid green. Note that until you press the AC On button on the box, the charge port indicators will glow red, and the instrument cluster will warn of a charging station fault.
How Much Power Does It Provide?
In total, the Power Box can support 30 amps (equal to 3,600 watts), but loading either of the two duplex outlets with more than 15 amps (1,800 watts) will trip a circuit breaker, turn off the ignition, and kill the party. We had a 12.5-amp space heater running on one and an 11-amp chainsaw working on the other, but a momentary stall of the chain on a small branch spiked the current and tripped the breaker. Similarly, an air compressor, plugged in alone, tripped the circuit because its startup current reaches 20 amps. We ran a hair dryer and the space heater, nearing the 30-amp total (notice the rounded 4-kW E-Hybrid display indication) for 20 minutes straight with no issue, until the battery ran low.
How to Reset the Power Box
If you trip the circuit breaker (via overload, by opening the hood, or some other means), the manual advises unplugging all loads from the box, unplugging the J1772 plug for at least 10 seconds, and restarting the procedure. However, at least once, the system flat refused to reset until the Jeep had been off (and recharged) overnight.
Three Modes of Operation
- Battery mode —perfect for preventing the engine from coming on and waking the campsite. Switches power off when the high-voltage battery hits its minimum state of charge. This is the default mode when you plug in and initiate Power Box while the engine's off.
- Generator mode —runs the engine to both maintain battery level and power your loads. Use this before bedtime when planning another day of silent wheeling and activate it by plugging in and initiating while the engine is running.
- Blended mode —Use this one to run your refrigerator during a power outage of indeterminate length. Plug in and initiate with the engine off and press the Max Regen button on the center stack.
How Long Will the Battery Last?
With the Jeep indicating 12 percent charge and 3 miles of range and the climate and audio systems off, we ran the space heater full blast on one circuit, while the other one alternately powered a hair dryer and the chainsaw. An hour of this usage mostly depleted the battery, suggesting the battery might have handled nearly 8 hours of such usage.
Can It Be Retrofitted?
No. Power Box operation requires a unique inverter in the vehicle featuring silicon that supports bidirectional charging. It was this Integrated Dual Charging Module (IDCM) that was among the supply-chain hold-ups that fouled the Power Box launch.
Can I Power Devices While Driving?
Nope. Many owner forum commenters lament the lack of onboard outlets to power fridges and recharge batteries for drones, cameras, and radios while driving, but the Wrangler cannot be driven when anything is connected to the J1772 port. The rear 12-volt outlet and 115-volt inverter plug can handle onboard loads of up to 400 watts.
Can I Power USB-C Devices?
Also no. There's a USB-C port on the Power Box, but it's strictly for recharging the internal battery that initiates communication with the Jeep. This recharges itself whenever plugged in, but after long periods of no use, the battery can run flat. A sequence of pressing the AC On button when disconnected starts a battery level check. Put this on your pre-camping-trip checklist!
Does the Power Box Work With Other Bidirectional EVs?
Doubtful; it appears the digital conversation that occurs between the Power Box and the vehicle happens in Jeepanese. The Ford F-150 Lightning refused to recognize it, but we wouldn't put it past a clever programmer to write some translation language to enable cross-manufacturer functionality in the future. We expect it may work with future Stellantis EVs and PHEVs.
Does It Support Vehicle-to-Grid Power Sharing?
Some EV owners can sign up to enable their power company to draw energy from their vehicle's battery to help support the power grid during times of peak usage. The 4xe battery isn't big enough to be of much use for this, so that functionality is not baked in.
Can I Power My House?
Not via the Power Box. There is an intrepid DIYer online who tapped the high-voltage battery with his own inverter box and managed to use it to power one half of his home's panel after shutting off most of the high-current circuits, but clearly Jeep doesn't endorse this approach.
Can I Buddy-Charge a Fellow 4xe?
There's not enough power here to be terribly useful, but sure, via 15-amp, 120-volt Level 1 charger you should be able to trickle charge another Jeep. Jeep does not currently support buddy-charging via cables featuring J1772 plugs on both ends.
Owners' Manual Caveats and Warnings
- Never use in wet/damp/humid environments (!?)
- Never plug anything in with wet hands
- Disconnect when there is risk of lightning
- Never use electrical equipment that requires a continuous power supply, such as medical equipment (don't let your 4xe inadvertently "pull the plug" on Grandpa!)
Parting Thoughts
We salute Jeep for offering its loyal outdoorsy clientele this useful accessory item. That said, we found the system to be considerably finickier and more prone to faults than the Pro Power Onboard system on our Ford F-150 Lightning , and we wish Jeep would offer the best of both worlds—an onboard 120-volt 15-amp outlet and the Power Box. Jeep also needs to either waterproof the box or shout down the lawyers and remove that owner's manual "dampness" warning, because Jeepers are gonna camp, and camping's gonna be wet.
I started critiquing cars at age 5 by bumming rides home from church in other parishioners’ new cars. At 16 I started running parts for an Oldsmobile dealership and got hooked on the car biz. Engineering seemed the best way to make a living in it, so with two mechanical engineering degrees I joined Chrysler to work on the Neon, LH cars, and 2nd-gen minivans. Then a friend mentioned an opening for a technical editor at another car magazine, and I did the car-biz equivalent of running off to join the circus. I loved that job too until the phone rang again with what turned out to be an even better opportunity with Motor Trend. It’s nearly impossible to imagine an even better job, but I still answer the phone…
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