When you’re building a van, the electrical system has a way of turning every other decision into a power question. The refrigerator needs to stay cold while you’re out for the day, your laptop still needs charging, and the air conditioner has to share the batteries with everything else. In Luna, our Sprinter, we installed an EcoFlow Independence Kit with two 5 kWh batteries and a Nomadic X3 24 V rooftop air conditioner, so understanding how those pieces work together matters as much as the battery capacity itself.

After seven years at SpaceX, I tend to approach a project by working backward from what it needs to do. For a van, that means figuring out what a normal day looks like, checking the loads that are hardest to support, and leaving enough room to service the equipment once the interior is finished. I want to be able to follow a cable, understand why it’s there, and get to its connections without taking the bed apart.

The EcoFlow kit brings several major electrical functions into one system, which makes that job more manageable. Its dedicated cables take care of many connections between the main components, while the Power Hub handles charging and supplies the van’s AC and regulated DC power. You still have to design the appliance circuits, secure the equipment, and give the batteries a realistic way to recharge, but you can spend more of your attention on how the system fits the van.

Understanding what comes in the Independence Kit

The kit makes more sense once you separate energy storage from power distribution. The batteries store the energy, the Hub converts and manages it, and the distribution panel divides it among the appliance circuits. The console gives you a convenient place to see what the system is doing without opening the electrical cabinet.

Each original 5 kWh battery is rated at 5,120 Wh, giving the pair 10.24 kWh of nominal storage. Their nominal voltage is 51.2 V, although the system is commonly described as 48 V. Because the Hub converts that power for its outputs, the battery voltage does not tell you what voltage is available at a particular appliance connection; that needs to be checked at the output you intend to use.

This guide covers planning and installation of the original US 120 V, 3.6 kW Power Kit, with particular attention to a two-battery van and a 24 V air conditioner. Match the labels on your Hub and panel before using its ratings; the newer 5 kVA system has different connections and limits. In the electrical sections below, AC means alternating current, while “air conditioning” refers to the rooftop cooling system.

The limits to check before assigning a circuit

For example, two 1,800 W AC appliances together reach the Hub’s nominal 3,600 W rating before you add any other AC load. That leaves no headroom, and the manual specifies reduced output under some temperature and battery-voltage conditions. Plan the combinations you will actually use, as well as each appliance on its own.

Working out how much electricity the van will use

I would start the load calculation with the air conditioner because it can draw a substantial amount of power for several hours, which quickly makes the smaller loads look modest. An appliance averaging 750 W over an eight-hour cooling period uses 6 kWh, before you account for the refrigerator, fans, computers, or losses in the electrical system. That does not make air conditioning impractical, but it does make a vague promise of “all-day power” fairly unhelpful.

It helps to check compatibility and runtime separately. The appliance needs the correct voltage and a circuit capable of supporting its maximum demand, regardless of how many batteries you install. Once that connection is properly designed, you can use its average consumption to estimate how long it will run.

The following example shows how the loads might add up over a day. These are planning assumptions rather than measurements from Luna, and the air-conditioning average will vary with the weather, insulation, thermostat setting, and compressor cycling.

At an assumed overall efficiency of 90%, supplying those loads would take about 8,178 Wh from the batteries. Our two-battery configuration provides 8,192 Wh between a full charge and a 20% reserve, so this example leaves almost no margin for additional cooling or idle consumption. Doing that arithmetic while the build is still on paper gives you time to adjust the loads, charging plan, or battery capacity before the cabinet dimensions are fixed.

Estimating runtime for your own loads

For a reasonably steady load, divide the energy you expect to use by the average power demand:

Runtime = nominal battery energy × usable charge window × estimated efficiency ÷ average appliance power.

With 10,240 Wh of nominal storage, a 20% reserve, 90% assumed efficiency, and 900 W of combined average loads, the estimate is about 8.2 hours. The calculator on this page lets you change those assumptions, which is useful for seeing how an extra load or a different reserve affects the result. Once you have measurements from your own installation, use those in place of the examples; if you measure at the battery, set efficiency to 100% because that reading already includes the conversion losses, and include system idle consumption in the measured load.

Planning the electrical cabinet before mounting anything

Before drilling, unpack the main components and lay them out with their actual cables, brackets, and restraints. A drawing can show that the boxes fit while missing the space needed to insert a connector or bend a cable around a wheel well. Measuring the complete cable route during this dry fit is much easier than discovering a short lead after the equipment is bolted down.

Think through how you will reach everything with the finished furniture in place. You need access to the mounting hardware during installation, the controls and protection during everyday use, and the heavy equipment if it ever needs to come out. A removable cabinet panel can be worth a little extra work now if it saves you from dismantling the bed later.

Supporting the batteries

The original 5 kWh batteries weigh about 89.5 lb each, so the pair adds roughly 179 lb before brackets and cables. Account for that weight in the van’s payload and layout, arrange help when positioning them, and secure the specified mobile restraints to a structure that can carry the load. A close-fitting cabinet should also keep luggage away from the connectors, but it does not replace the required battery restraint hardware.

If the batteries will be stacked, check the lower battery’s cable route before placing the upper one. The connection that looks easy to reach with one battery installed can become awkward as soon as the second is in position. Leave enough access to follow the manufacturer’s cable and restraint arrangement without trapping the lower lead.

Keeping the Hub ventilated

In the original quick-start guide’s wall-mount orientation, the Hub requires more than 100 mm above, below, and to the right, and more than 50 mm to the left. Those dimensions apply to the Hub, so use the battery instructions separately when arranging the battery mounts. The cabinet also needs an air path into and out of the space; clearance around the equipment will not provide ventilation if it is enclosed in a sealed box.

It is worth looking at the layout as it will be used on a trip, with bedding and bags in the garage. Locate the ventilation openings where stored gear cannot easily cover them, and consider where the Hub’s fan noise will be heard from the bed. Both are easier to address before the surrounding cabinetry is finished.

Gathering the tools and installation supplies

The kit’s plug-in connections simplify the main assembly, but the appliance wiring and vehicle connections still need properly prepared terminals, protected cable routes, and suitable test equipment. Choose tools for the connections in your own design; there is no reason to buy a large lug crimper unless you actually need to make those terminations, and the standard battery leads should not need to be cut or reterminated to install the kit.

For each custom circuit, select the cable, terminals, and protective device together. Maximum current, cable length, installation conditions, and acceptable voltage drop all affect that choice, which is why a wire gauge copied from another build is not enough information by itself. Make those decisions before ordering so the wire, connectors, and tools are compatible when they arrive.

Make a circuit schedule you can use at the workbench

Before cutting cable, give each circuit an identifier and record the information below. Use the same identifier on its panel label, cable ends, and installation photos so you can trace it later. The printable build worksheet includes a blank circuit schedule, commissioning checklist, and runtime log for your own installation.

A useful cable label might read “DC-03 · Water pump,” with the equipment and protection details on the schedule. If a cable-sizing method asks for round-trip length, use the complete outgoing and return path rather than entering the one-way measurement. Keep both the measured route and the calculation convention in your notes so that distinction does not disappear later.

Installing the EcoFlow system

Keep the wiring diagram and installation instructions for your exact kit beside you as you work. This walkthrough explains the sequence and the practical checks, while those documents specify the connections, fasteners, and tightening values for your hardware. Before making electrical connections, isolate shore, solar, and vehicle charging, keep the batteries switched off, and verify the relevant circuits are de-energized; a dark console alone does not establish that the wiring is safe to touch.

1. Mount the Power Hub

Mark the Hub’s position with its ventilation clearances and connector space included, then inspect behind the mounting surface for wiring, plumbing, and vehicle structure. Use the supplied template where provided and choose fasteners suited to the supporting material, with enough engagement to hold securely without protruding into anything behind it. For the original wall-mount arrangement, the support bracket carries the Hub while the remaining brackets secure it in place.

After fitting the required brackets and tightening the hardware as specified, bring each planned cable to its port to check the approach. The cabinet front should fit without pressing on a connector, and the cable should enter without being forced into a tight bend. Resolve any interference now, while moving the Hub is still straightforward.

2. Install and restrain the batteries

Dry-fit the battery mounts and restraints before fastening them down, checking the complete stacked arrangement if that is your chosen layout. Following the battery instructions, fit and route the lower battery’s cable before placing the upper battery over it, leaving the Hub end disconnected until the system is ready for battery connection. That sequence preserves access to the lower connector and avoids having to lift the upper battery out again.

Install all specified restraint hardware and straps, then check that neither cable is pinched or exposed to stored equipment. Each battery uses its own specified cable to the Hub; stacking the cases does not mean wiring the batteries together in series. Before continuing, make sure the finished arrangement allows the batteries and their connections to be serviced.

3. Fit the distribution panel and identify the circuits

Mount the panel where you can reach its protection and wiring after the interior is complete, using the cutout or bracket arrangement specified for that panel generation. Prepare only the cable entries you need, remove drilling debris, and fit the required edge protection and strain relief before pulling in the wires. Leaving debris inside an electrical enclosure creates an avoidable problem that can be difficult to spot once the cables are in place.

Make a circuit schedule before terminating anything, recording the appliance name, voltage, maximum load, conductor size and length, and fuse or breaker. Label both ends of each cable with the same name so “water pump” on the panel means the same thing at the pump. Keep a copy of that schedule with the system documents, where you can find it without relying on your memory of the build.

4. Route and terminate the output and appliance cables

Connect the Hub’s AC and DC output leads to their corresponding panel connections by following the printed labels and wiring diagram. Photographs can help with orientation, but they should not be the way you identify a port. Route the appliance cables along the planned paths, keeping them clear of heat and moving parts, supporting them against vibration, and protecting every passage through an edge or panel.

Prepare each conductor and terminal according to the connection requirements, checking for damaged strands, exposed copper, and insulation caught in the clamping surface. Use the specified tightening values for screw terminals and leave the prescribed bend space at connectors. Before closing the covers, photograph the cable routes and important terminations so you have a useful record of what is behind the furniture.

Have the AC protection and grounding arrangement checked by someone qualified in RV electrical installations, including its behavior on both shore and inverter power. Neutral-to-ground connections depend on the system and operating mode, so a familiar household-panel arrangement is not enough to establish what this installation requires.

5. Mount the console and connect the controls

Position the console where you can check charging and battery status from the living space, then plan the cable route behind its bracket before drilling. Connect the specified communication cables between the Hub, panel, and console, fitting any required terminators in the positions shown for your configuration. Although the connectors may resemble ordinary network connections, they serve the kit’s control system and should not be connected to a network switch or router.

Trace the communication path once everything is mounted and check that each connector is fully engaged. This gives you a useful starting point if a component is missing from the console during startup, because a device can have its power cable connected while still having a communication fault.

6. Complete the charging connections

Finish each charging circuit while its source remains isolated, using the approved connection points and protection for that source. For shore power, document the inlet, cord, protective equipment, and available supply, then set the permitted input to suit the outlet you will actually use. A 30 A inlet on the van does not increase the capacity of a lower-rated household circuit.

For alternator charging, work from the vehicle’s approved connection arrangement and account for cable length, protection, the vehicle’s own electrical demand, and alternator output under the expected operating conditions. A larger alternator’s nameplate rating does not establish how much charging power will reach the house bank, because the vehicle and the Hub impose their own limits. Confirm vehicle fitment and the supported charging connection before ordering an upgrade.

For solar, check the array’s cold-weather open-circuit voltage and current against the exact Hub input limits before choosing series or parallel wiring. Decide which ports will serve the panels and which will serve the alternator, since a shared input cannot do both jobs at once. Keep the sources disconnected while routing and labeling the leads, then check polarity, protection, and the permitted input range before energizing each one.

7. Inspect the installation and connect the batteries

With the loads off and external charging disconnected, work through the finished installation against your circuit schedule and wiring diagram. Check polarity, labels, terminal preparation, tightening, protection, restraints, and communication connections, then remove loose tools and hardware and close the appropriate enclosures. It is much easier to make a careful inspection at this stage than to troubleshoot several unknowns during the first startup.

With the batteries switched off, connect each one to the Hub using its specified cable and the manufacturer’s connection procedure. Treat the system as potentially energized from that point and move to the controls rather than continuing wiring work. Follow the matching startup instructions, confirm that both batteries and the intended control components appear without unresolved faults, and verify the selected DC output voltage before enabling any DC appliance.

Supplying our Nomadic X3 24 V air conditioner

The Nomadic X3 in Luna is the 24 V DC version. That detail matters when choosing the supply, harness, and any voltage conversion, because Nomadic’s current product page groups several X3 generations and voltages together. Select 24 V and match the actual unit’s model label when ordering accessories; a cable advertised simply for an “X3” is not enough information to establish that it fits your installation.

The original distribution panel’s 20 A DC branches are the first limitation to understand. A load averaging 750 W at a nominal 24 V draws about 31 A, already above one branch’s rating; even at 26.4 V, the same power is about 28 A. Those calculations explain why the ordinary branch is unsuitable, but they are not the maximum-current values to use when sizing the HVAC circuit. Use the air conditioner’s nameplate and installation requirements for that design.

There is also a voltage decision for the rest of the van. The Hub’s regulated DC output is set to one voltage, so changing it to 24 V would affect every load connected to that output. If your refrigerator, lights or pump require 12 V, a high-current 24 V air conditioner needs a separately designed, manufacturer-supported supply arrangement; turning up the panel voltage would put those 12 V loads at risk.

Depending on the supported arrangement, the HVAC supply may need a dedicated connection and a converter. Before ordering those parts, get written confirmation for the exact Hub and X3 combination, including the connection point, voltage range, continuous and maximum current, cable requirements, and protection on both sides of any converter. A nominal 48 V battery system does not mean that a cable from a battery-side port can be connected directly to a 24 V appliance.

Keep that approved connection diagram with the circuit schedule and label the HVAC supply separately. The installation sequence above covers the standard EcoFlow components; this high-current connection must follow the instructions for its specific hardware.

Checking the system during its first power-up

Once the console recognizes the system, bring the loads on individually so you can confirm each circuit’s operation before testing the combinations you expect to use together. Keep the cabinet accessible during commissioning and watch for faults, abnormal heat, or unexpected shutdowns as the load increases. A working display is a useful beginning, but the meaningful check is how the installation behaves under the van’s normal demand.

If a protective device trips, investigate the cause before resetting it, using the circuit schedule and equipment instructions to narrow down the problem. After the system passes the individual-load, combined-load, and charging checks, save the installed settings, final photographs, and circuit list together. Those records will make maintenance and later additions much easier to understand.

Measure runtime under conditions you can describe

An overnight runtime claim is only useful if the reader knows how hot it was, what the thermostat was set to, and what else was running. Once commissioning is complete, use a representative cooling session to replace the calculator’s assumptions with measurements. Keep the electrical enclosures closed during operation and use the console or installed monitoring; any additional electrical measurements should be made by someone competent with the equipment.

1. Record the conditions and starting state. Note the date, shade or sun exposure, outside and inside temperature, thermostat setting, operating mode, starting battery charge, and reserve setting.
2. Establish what is running. List the refrigerator, fans, chargers and other active loads. For a battery-only test, disable charging through the prescribed controls or isolation procedure and confirm there is no input; do not unplug energized sources to create the test condition.
3. Log the complete session. Record time, battery charge, temperatures and reported power at regular intervals, such as every 30 minutes. Keep the initial cooldown in the record and distinguish it from the later period when the compressor may cycle.
4. Stop at the planned reserve or a fault. You do not need to run the bank to shutdown to learn how the system behaves. Record the ending state and any thermostat or load changes rather than presenting them as unchanged conditions.
5. Use the correct measurement boundary. Energy measured over the whole session divided by elapsed time gives average power at that measurement point. If it is battery-side energy, it already includes conversion and idle losses; do not apply the calculator’s efficiency allowance a second time.

Battery percentage is useful for documenting a trip, but multiplying a short percentage change by nominal capacity gives only a rough energy estimate. A measured energy total is a better basis for reporting consumption. Without one, report the observed duration, charge change and conditions directly instead of turning them into a precise efficiency claim.

When the first checks do not pass

Planning how the batteries will recharge

The charging plan needs to support your travel habits as well as the appliances. Driving most days gives alternator charging regular opportunities to recover energy, while spending several days parked puts more responsibility on solar and shore power. Work through a likely trip rather than assuming that a charging source will always be available when the batteries need it.

If a day takes 8 kWh from the bank, replacing that energy at a steady net rate of 1 kW would take about eight hours; at 2 kW, it would take about four. Actual charging rates vary, but these examples show why recovery time belongs in the original design. If a source supplies 1,000 W while operating loads use 700 W on the same accounting basis, only about 300 W remains before other losses, so the charging icon alone will not tell you whether tomorrow’s energy is being replaced fast enough.

The small solar array in the budget illustrates an important limit. Two 100 W panels, an assumed four peak-sun-hours and an 80% daily yield factor produce about 640 Wh per day in that example: 200 W × 4 h × 0.80. “Peak-sun-hours” is the day’s solar energy expressed as equivalent hours at full rated output, not simply the number of daylight hours. That example replaces only about a tenth of the 6 kWh cooling load above, so the array is a supplement to the charging plan rather than a way to sustain that cooling schedule by itself.

Actual panel placement, shade, weather and temperature can change the result substantially. Compare the energy your array produces over a day with the energy the van uses, and include the driving or shore-power opportunities that close the gap.

A line-by-line budget for a similar electrical build

The Power Kit is the largest purchase, but it is only part of the installed cost. I would also allow for the charging connections, cable protection, outlets, lighting, mounting materials, and the appliances the system will run, because those smaller purchases are easy to lose track of when they arrive in separate orders.

This is a planning budget in US dollars, not a record of what we paid for Luna. Quantities and optional appliances describe one example of a well-equipped van. The rows marked as allowances are estimates rather than product quotes, while listed reference prices were checked September 4, 2026. Some original-generation products are sold out, so the totals below are a budgeting baseline rather than an orderable shopping cart.

The links below take you to the kit and air conditioner we use, along with clearly labeled product examples and supplier catalogs for the remaining budget items. Choose Independence / 10 kWh on EcoFlow’s page and 24 V on Nomadic’s X3 page, then match the air conditioner’s generation. An example link does not mean that product is installed in Luna, included at the allowance shown, or compatible with every circuit; check the selected model’s voltage, dimensions and ratings before ordering.

For the custom HVAC connection and any converter, use the supplier inquiry links to obtain a supported parts specification before purchase. The roof-hatch link is also a supplier inquiry: the current category includes manual hatches, which should not be substituted for the powered assembly budgeted here.

Budget summary

The power infrastructure comes to $17,211.99 before air conditioning, the other powered appliances, tools, services, shipping, tax and contingency. The full example reaches about $34,000, largely because it includes the rooftop air conditioner, refrigerator and a powered skylight as well as the electrical system. Remove equipment you do not need instead of treating every row as a requirement.

The bundle is counted once. Its included batteries, Hub, panel, console, standard interconnects and supplied mounting accessories do not receive separate charges. The budget also assumes the required standard charging leads are in the packing list; add a missing or longer cable only when the chosen installation requires it. The dedicated HVAC accessory and converter are conditional allowances, not an instruction to buy an unverified combination.

The tax percentage is a cash reserve rather than a statement of the tax rate that applies to your order. Shipping and outside-service costs also need quotes. This assumes you do the general cabinet, branch-wiring and rooftop installation work yourself; a complete professional installation needs its own labor quote. The contingency is applied once to equipment and tools, not to tax, shipping or services.

A hydronic heating package, water-heater hardware, solar roof rack, existing phones/computers, subscription fees and the van’s original electrical equipment are outside this electrical-installation example. Their branch wiring is covered where needed, but the assemblies themselves belong in the heating, plumbing, roof or personal-equipment budget. If any of those are part of your intended electrical purchasing scope, add them explicitly before using this as the whole-van total.

Price references: the original EcoFlow 10 kWh Independence Kit is listed at $13,199 and the EcoFlow 100 W flexible panel at $199; both listings show sold-out status. The 25-foot shore cord is listed at $59.99. The Nomadic unit and install-kit amounts remain allowances because the visible X3 listing and install-kit listing include several generations and voltages. Select the exact unit before comparing prices; the amounts above remain planning allowances.

Choosing a system you can live with

The appeal of an integrated kit is that the batteries, charging hardware, controls, and main connections are designed to work as a system. In exchange, you are committing to that manufacturer’s cables, supported accessories, and replacement components, which makes compatibility and parts availability worth checking before a large purchase. Give the same attention to the equipment’s physical fit, because even a well-matched electrical system can be frustrating to maintain in an inaccessible cabinet.

For a build like Luna, I would put the most effort into a realistic load calculation, a supported air-conditioning connection, secure mounting, and enough charging to recover between stops. Those decisions affect everyday use much more than how tidy the equipment looks in a product photo. The goal is to understand the installation well enough that you can enjoy using the van and still know where to start when something needs attention.