A Comvolt power station works fine sitting on the floor with things plugged into it. Most people who buy one for a van, truck camper or travel trailer want it fixed in place, charging from the vehicle and feeding the rig's 12V circuits. This guide covers what Comvolt's manuals say about where it goes, how to wire the included 30A DC-DC charger, and how to connect loads, a 12V air conditioner and an expansion battery. Have a qualified technician do the wiring if you aren't comfortable working on vehicle electrics.
Pick the spot
Start with weight and size. These are not small boxes:
| Unit | Weight | Size |
|---|---|---|
| Comvolt 2200 | 43.4 lb | 14.5 × 7.3 × 9.7 in |
| Comvolt 4200 | 65.5 lb | 17.2 × 7.3 × 10.1 in |
| Comvolt 6000 Pro | 122 lb | 18.5 × 9.7 × 13.5 in |
| 4000 Expansion Battery | 68.4 lb | 13.7 × 7.7 × 10.1 in |
| 6000 Expansion Battery | 95 lb | 18.9 × 7.4 × 11.3 in |
Comvolt's handling instructions say to always keep the units upright. Strap or bracket them to the floor or a solid base so they can't slide under braking. In a trailer, low and close to the axles is the usual choice for weight balance.
Ventilation clearances
The stations have cooling fans, and Comvolt's manual is specific about airflow:
- Open space: preferred.
- Semi-enclosed (a cabinet with one open side): face the fan side toward the open area, leave at least 6 inches of clearance on the opposite side, and provide a ventilation opening of at least 6 inches high by 7 inches wide.
- Fully enclosed: cut ventilation openings of at least 6 × 7 inches in both the front and rear panels, put the fan side as close to the wall as practical, and keep at least 6 inches of clearance on all other sides.
For the expansion batteries in a semi-enclosed space, Comvolt asks for 6 inches between the Anderson ports and any surface, for cable access. The 6000 pack also needs 6 inches in front of its display so you can read it.
Wire the 30A DC-DC charger
Every Comvolt station comes with a 30A DC-DC charger, an 8 ft alternator charging input cable, an output cable and an ACC control switch. Comvolt's installation steps are:
- Route the input wiring harness from the engine bay into the cabin where the DC-DC charger is installed.
- Connect the harness to the charger's input terminals.
- Connect the positive (red) lead to the vehicle battery's positive terminal using the pre-installed ring terminal.
- Connect the negative (black) lead to a solid chassis ground or the vehicle battery's negative terminal.
- Mount the in-line fuse holder firmly in the engine bay, close to the battery.
- Connect the control wire: to an accessory (ACC) feed for automatic charging whenever the key is ON, or to a 12V cigarette-lighter socket for manual on/off with the switch.
- Plug the charger's XT90 output cable into one of the XT90 inputs on the front of the station.
Comvolt gives a tightening torque of 3.0–4.0 N·m for the wiring connections, with a maximum of 6.0 N·m. Loose terminals overheat, and over-tightened ones can crack the fuse holder. Mount the charger somewhere dry and ventilated, away from engine parts, exhaust and anything flammable, with room to plug and unplug the cables.
At roughly 12.8V, 30A is about 380W, so an hour of driving puts back something like 380Wh. That's our arithmetic, not a Comvolt figure. For how this compares with other ways of charging a station on the road, see charging a power station while you drive.
In a towed trailer
Comvolt's instructions describe the charger fitted in the vehicle whose battery it draws from. In a travel trailer the station is behind the truck, and the 7-pin connector's charge wire is usually too thin for a big lithium battery. Our 7-pin trailer charging guide covers the options. The other route is solar, 400W on the 2200 or 4200 or up to 800W across the 6000 Pro's two inputs, with the wall charger at a campsite pedestal or generator (500W on the 2200 and 4200; Comvolt doesn't state the 6000 Pro charger's wattage).
Connect your 12V loads
The station's 120A Anderson port is the main 12V feed, and the 6000 Pro has two, each with its own breaker. For more than a couple of loads, Comvolt's DC PDU splits that feed into eight switched, protected circuits. Our Magic Power system guide explains how it connects.
The main power switch turns on all the DC outputs. The inverter won't run while the main switch is off. Comvolt's 4200 manual adds an important startup rule: turn off high-power 12V loads such as a fridge or air conditioner before you switch the DC output on. If heavy loads are already running when DC comes on, the station may trip its short-circuit protection and shut down. To recover, switch off and unplug the loads, press the Reset button on the back, and start again in the right order. Comvolt also recommends leaving the DC switch on in daily use, and switching the main switch off when the station is not in use, to prevent drain.
A 12V air conditioner on the Anderson port
Comvolt's manuals show a 12V air conditioner connected with the provided Anderson cable through an Anderson fuse holder:
- If the air conditioner has its own internal fuses, the diagram uses the 150A fuses in the Anderson fuse holder.
- If it doesn't, the diagram keeps the 150A fuse holder and adds a second in-line fuse rated at 1.5 times the air conditioner's rated current.
Assemble the fuse holder in Comvolt's order, from the bottom: flat washer, fuse, cable lug with wire, flat washer, lock washer, hex nut. Comvolt warns that getting it wrong can overheat the cables. For how much battery a DC air conditioner needs, see how much battery runs a Nomadic DC air conditioner.
120V circuits
The simplest 120V setup is plugging appliances into the station's outlets. The 4200 adds an L/N/GND AC terminal block for a hard-wired circuit, and the 6000 Pro ships with the cable for Comvolt's AC PDU. Anything wired into the RV's 120V system needs a qualified electrician and must not back-feed the shore-power inlet.
Adding an expansion battery
- Connect the pack only through the station's rear Anderson port, with the supplied cable.
- Check that the voltage difference between the station and the pack is under 1V before connecting.
- Run the RJ45 network cable between them so they share status, and make sure each battery has its own battery ID, as Comvolt's manual requires. Ask us how to set the pack's ID for your setup.
Before the first trip
A new station shows an estimated state of charge. Comvolt recommends one full cycle so it can learn the capacity: charge to 100% in one session until the charging current drops to 0A, then discharge to 0% in one session until the output current drops to 0A. Then install the Comvolt app (iOS and Android) and pair it over Bluetooth.
Comvolt also makes a tongue-mount enclosure for the 4200 that we haven't listed yet. Ask us if you want one.
FAQ
Can I mount a Comvolt station on its side?
Comvolt's storage and transport instructions say to always keep the unit upright, so we'd mount it standing.
Do I need a separate DC-DC charger?
No. A 30A DC-DC charger, its cables and an ACC control switch come with every Comvolt station.
Can it go in an outside storage bay?
Only if you can give it the ventilation clearances above and the bay stays within Comvolt's ranges: -13°F to 149°F in use, -13°F to 131°F while charging, and 14°F to 95°F if it sits there unused. Our Comvolt cold-weather guide covers winter use.
Still choosing a station? Compare them in Comvolt 2200 vs 4200 vs 6000 Pro.