Understanding Campervan Power (Ah vs Wh vs Watts)
Before diving in, it’s important to understand the three key measurements you’ll see everywhere:
Amp Hours (Ah) & Watt Hours
You’ll see battery capacity measured in two common ways, either in Amp hours or Watt hours
- Measures battery capacity (storage)
- 100 Ah 12V battery
- 1,200 Wh battery
- Both of these would be the same size
Comparing Watt Hours & Amp Hours
- Amp hours to Watt hour formula: Ah x voltage = Watt hours
- Example: 100Ah × 12V = 1,200Wh
- Watts Formula: Watts × Hours = Watt Hours
Watts (W)
- Measures power output (how much you can run at once)
Examples:
- Laptop: ~60W
- Fridge: ~50–100W
- Induction cooktop: 1,500W+
Why This Matters:
- Ah / Wh = how long your system lasts
- Watts = what your system can handle at once. Not all batteries have the ability to handle a large amount of devices / wattage at once.
- If you are using 1500 Watts, and have a 1500 Watt hour battery, it would last 1 hour
A complete campervan power setup needs both enough capacity (Wh) and enough output (W).
What Is a DIY Campervan Electrical System?
A DIY campervan electrical system is a fully custom setup where you wire together individual components.
Core Components
- Battery (often 100Ah–400Ah lithium = ~1,200Wh–5,000Wh+)
- Inverter (1,000W–3,000W+) – An inverter attached to a battery converts low-voltage Direct Current (DC) electricity (typically 12V, 24V, or 48V) into high-voltage Alternating Current (AC) electricity (110V-120V or 220V-240V). This allows you to run standard household appliances, such as laptops, cooktops, and power tools, using stored energy from car batteries, RV banks, or solar setups.
- Solar panels (100W–600W+)
- DC-DC charger (alternator charging)
- Fuse box, wiring, distribution
- Outlets / Light switches
Pros of a DIY Campervan Electrical System
Massive Expandable Capacity
You can build systems like 400Ah lithium (~5,000Wh) or 800Ah+ setups for full-time living.
High Output Capability
Run induction cooktops (1,500W+), coffee makers, and power tools.
Fully Custom Design
Everything is tailored to your van/camper and usage.
Cons of a DIY Campervan Electrical System
Complexity
You need to understand voltage, current, load calculations, and safe wiring practices.
Time Investment
Planning takes hours to days, and installation can take days to weeks.
Troubleshooting
Multiple components mean more potential failure points.
DIY Campervan Electrical System Cost
| Component | Specs | Cost |
|---|---|---|
| Lithium battery | 100Ah–300Ah (1,200–3,600Wh) | $800 – $3,000 |
| Inverter | 1,000W–3,000W | $200 – $1,500 |
| Solar panels | 100W–600W | $300 – $1,500 |
| DC-DC charger | 20A–60A | $150 – $500 |
| Wiring & install | — | $200 – $800 |
| Total | — | $1,500 – $7,000+ |
Large builds (500Ah+ / 6,000Wh+) often exceed $8,000–$10,000. Most van builds fall between $3,000 and $5,000.
What Is a Portable Power Station for Campervans?
A portable power station is an all-in-one system that includes a battery (Wh), inverter (W output), charge controller, and built-in ports.
Important Reality: It’s Not Just Plug-and-Play
Most van builds still include:
- Overhead lights
- Dimmer switches
- USB outlets
- 12V ports
This means you’ll still likely run wiring through your van and install switches and distribution.
The difference is:
- You’re not building the core electrical system
- You’re wiring end-use devices only
This still saves a massive amount of time and complexity.
Pros of Portable Power Stations
Extremely Simple Core System
No need to size inverters, design battery banks, or wire charge controllers.
Fast Setup
From box to usable power in minutes.
High Capacity Options
Modern systems offer 2,000Wh–6,000Wh+ and 2,000W–3,500W+ output. Many systems have modular add ons to hit any capacity needs.
Portable + Multi-Use
Use it in your van, at camp, or as home backup power.
Cons of Portable Power Stations
Higher Cost Per Wh
You’re paying for convenience and integration. Sometimes, Black Friday and holiday deals can bring costs down substantially.
Expansion Limitations
Some systems scale, but not all.
All-in-One Risk
If something fails, the whole unit is affected.
Portable Power Station Cost
| System Size | Capacity | Cost |
|---|---|---|
| Small | 300–500Wh | $250 – $600 |
| Medium | ~1,000Wh | $700 – $1,500 |
| Large | 2,000–4,000Wh | $1,500 – $4,000 |
| Expandable Systems | 4,000Wh–10,000Wh+ | $3,000 – $8,000+ |
DIY vs Portable Power Station
| Feature | DIY System | Power Station |
|---|---|---|
| Setup Difficulty | High | Very low |
| Install Time | Days–Weeks | Hours |
| Capacity | Unlimited | High (but capped) |
| Output (Watts) | Very high | High |
| Portability | None | High |
| Wiring Required | Full system | End-use only |
My Campervan Power Setup (Real-World Example)
My system includes:
- Bluetti Apex 300 Portable Power Station (2,764.8 Wh)
- Bluetti B300K Expansion Battery (2,764.8 Wh)
- Hub D1 Power Hub for Apex 300
- Alternator charging setup (Bluetti Charger)
- Portable solar panels (200 W)
Why I Love This Setup
Massive Capacity
Several thousand watt-hours of capacity, equivalent to a large multi-battery DIY system. (5,530 Wh)
Serious Output Power
Powering two induction cooktops (~3,000W total) plus a fridge at the same time.
Alternator Charging
Charging while driving reduces reliance on solar or shore power. Alternator charges between 500-600 Watts on my Ram Promaster 2500. I don’t sit in one place for long, so every day i’m driving a little, and every few days quite a bit, which recharges the battery substantially.
Solar Flexibility
Portable panels allow parking in shade while charging in the sun. Not mounting panels on the roof is saving 1-2 MPG.
Built-In Redundancy
Expansion battery adds flexibility and backup. I can always add more power or add permanent solar panels. In addition, if one battery fails, the expansion, or core battery acts as a backup.
Home Backup Capability
Can run a fridge and multiple appliances during outages off the van system.
No Build Headaches
Skipped complex wiring and system design entirely.
Which Campervan Power Setup Should You Choose?
Choose a Portable Power Station if:
- You want simple, fast setup
- You’re doing weekend or adventure trips
- You don’t want to learn electrical systems
- You still plan to wire lights and outlets—but not build a full system
Choose a DIY System if:
- You need maximum capacity (6,000Wh+) but need to minimize costs
- You’re living full-time in your van
- You want full customization
- You’re comfortable with electrical work
How Much Power Do You Actually Need?
One of the most common questions when building a campervan power setup is: how much power do you actually need?
The answer depends entirely on what you’re running and how often you’re using it. The easiest way to figure this out is to estimate your daily power usage in watt-hours (Wh).
| Device | Watts (W) | Hours/Day | Daily Usage (Wh) |
|---|---|---|---|
| Fridge | 60W | ~10 hrs (cycled) | ~600Wh |
| Laptop | 60W | 3 hrs | 180Wh |
| Lights | 10W | 5 hrs | 50Wh |
| Phone Charging | — | — | 20Wh |
| Cooking | 1500W | 15 minutes | 375Wh |
| Total | — | — | ~1,225Wh/day |
General guidelines:
- Light / weekend use: 500–1,500Wh/day
- Moderate use: 1,500–3,000Wh/day
- Heavy use (cooking, full-time): 3,000Wh+ per day
This is where understanding Ah vs Wh vs watts becomes critical:
- Watt-hours (Wh) = how long your power lasts
- Watts (W) = what you can run at once
Dialing this in helps you avoid both underbuilding and overspending.
Adding solar panels or alternator charging will change how much power you produce each day to recharge your battery.
Common Campervan Power Mistakes
Most people don’t get their power system perfect on the first try. Here are some of the most common mistakes—and how to avoid them.
- Underestimating power needs: Especially for fridges, cooking, starlink (if applicable), heater setup, and charging multiple devices
- Overbuilding the system: Spending thousands more than necessary “just in case”
- Relying only on solar: Cloudy days and shade make solar inconsistent
- Ignoring alternator charging: One of the most reliable charging sources while traveling
- Confusing watts and watt-hours: Not understanding the difference leads to poor system design
A well-balanced system focuses on real-world usage, not theoretical maximums.
Solar vs Alternator Charging: What Matters More?
Both solar and alternator charging are valuable, but they serve different purposes.
Solar Charging
- Great for staying parked for long periods
- Works best in sunny conditions
- Can be inconsistent depending on weather and shade
Alternator Charging
- Charges your system while driving
- Extremely reliable
- Often much faster than solar
Best setup:
- Use solar to maintain power while parked
- Use alternator charging for consistent daily recharging
In real-world use, alternator charging is often the difference between constantly managing power, and not thinking about it at all. With my van, I elected to not place solar panels on my roof, but keep portable solar panels in the back in case I need to add any additional power.
Wiring a Van with a Power Station (What You Still Need to Do)
Even with a portable power station, most campervan builds still require some wiring.
You’ll likely still install:
- Overhead lighting circuits
- Dimmer switches
- DC-DC Alternator charger
- USB, USBC, and 12V outlets
- Possibly AC outlets tied into the inverter
- Solar panel wiring (if applicable)
The key difference:
- You are not wiring the core electrical system
- You are wiring end-use devices only
This dramatically reduces:
- Complexity
- Install time
- Risk of wiring mistakes
You still get a clean, functional van setup—without building a full electrical system from scratch.
Real-World Campervan Power Setups
Weekend Adventurer
- Power needs: 500–1,500Wh/day
- Typical use: lights, fridge, phone, occasional laptop
- Alternator charging likely enough
- Best setup: portable power station (1,000Wh–2,000Wh range)
Remote Worker
- Power needs: 1,000–2,000Wh/day
- Typical use: laptop, Starlink, fridge, lights, small amount of cooking
- Alternator charging likely enough
- Best setup: larger power station or expandable system
Full-Time Van Life
- Power needs: 2,000-3,000Wh+/day, but more staying put for longer durations
- Typical use: cooking, heating, full-time living
- Alternator charging and solar suggested
- Best setup: large DIY system or expandable power station
Matching your setup to your actual lifestyle is the most important part of the decision.
Expandable Power Systems Explained
Many modern power stations now offer expansion batteries, allowing you to increase total capacity without replacing your system.
How it works:
- Add external battery packs to increase total watt-hours (Wh)
- Maintain the same inverter and output (watts)
Benefits:
- Scale your system over time
- Lower upfront cost compared to maxing out immediately
- Add redundancy with multiple battery units
This approach combines the flexibility of DIY systems with the simplicity of all-in-one setups.
Frequently Asked Questions
How many watt-hours do I need for van life?
Most people need between 1,000Wh and 3,000Wh depending on usage. Full-time setups often require more.
Can a power station run a campervan fridge?
Yes. Most fridges use 400–800Wh per day, which is well within the range of mid to large power stations.
Is solar enough for a campervan?
Solar helps, but it’s rarely enough on its own. Most setups benefit from combining solar with alternator charging.
Can you charge a power station while driving?
Yes. With the right setup, alternator charging allows you to recharge your system while driving between destinations.
Is a 100Ah battery enough?
A 100Ah battery (~1,200Wh) is enough for light use, but most people will want more capacity for multi-day trips.
Final Thoughts
For most people, a portable power station combined with simple wiring for lights and outlets that is supported by alternator and solar charging is the sweet spot.
You get:
- Plenty of power (Wh)
- Strong output (W)
- Far less complexity
And most importantly, you get on the road faster.
Max DesMarais is the founder of myoutdoorbasecamp.com. He has a passion for the outdoors and making outdoor education and adventure more accessible. Max is a published author for various outdoor adventure, travel, and marketing websites. He is an experienced hiker, backpacker, fly fisherman, backcountry skier, trail runner, and spends his free time in the outdoors. These adventures allow him to test gear, learn new skills, and experience new places so that he can educate others. Max grew up hiking all around New Hampshire and New England. He became obsessed with the New Hampshire mountains, and the NH 48, where he guided hikes and trail runs in the White Mountains. Since moving out west, Max has continued climbed all of the Colorado 14ers, completed multiple ultra marathons, including the 100 mile Run Rabbit Run, is always testing gear, learning skills, gaining experience, and building his endurance for outdoor sports. You can read more about his experience here: hikingandfishing/about
