You've decided to add solar panels to your campervan - great choice! But then you see terms like "MPPT" and "PWM" thrown around, along with confusing voltage specifications. What does it all mean, and why does everyone recommend MPPT controllers?
This guide breaks down Maximum Power Point Tracking (MPPT) technology in plain English, explains why it's worth the investment, and helps you choose the right controller for your system.
Quick Answer
MPPT controllers are 20-30% more efficient than PWM controllers, especially in low-light conditions. For campervan solar systems, the extra cost pays for itself through better charging performance.
What is MPPT?
The Simple Explanation
Solar panels produce different amounts of power depending on conditions (sunlight intensity, temperature, angle). MPPT (Maximum Power Point Tracking) is a technology that constantly adjusts the electrical operating point to extract the maximum possible power from your panels at any given moment.
Think of it like a smart gearbox that always finds the perfect "gear" for your solar panels to work most efficiently.
MPPT Controllers
- 20-30% more efficient than PWM
- Excellent in low-light/cloudy conditions
- Can handle higher voltage panels
- Temperature compensation
- Better battery health
Recommended for campervans
PWM Controllers
- •Cheaper upfront cost
- •Simpler technology
- •Wastes 20-30% of power
- •Poor in partial shade
- •Panel voltage must match battery
False economy for most systems
Real-World Example
A 200W solar panel in UK winter conditions might produce:
- PWM controller: 30-40W (losing 60-70% to inefficiency)
- MPPT controller: 50-60W (extracting maximum available power)
That extra 20W doesn't sound like much, but over a cloudy winter week, it's the difference between a charged battery and a flat one.
Victron MPPT Controllers
We exclusively install Victron Energy MPPT controllers because they're simply the best on the market. Here's why:
SmartSolar Range
Built-in Bluetooth for smartphone monitoring via the free VictronConnect app.
- • 75/10, 75/15 - Small systems (100-200W)
- • 100/20, 100/30 - Medium systems (200-400W)
- • 100/50 - Large systems (400-700W)
BlueSolar Range
Same MPPT technology without built-in Bluetooth (can add dongle later).
- • Slightly cheaper than SmartSolar
- • Same efficiency and reliability
- • Can add Bluetooth dongle for £25
Why Victron?
- Proven ultra-high reliability
- 5-year warranty standard
- Advanced MPPT algorithm
- Perfect lithium battery profiles
- VictronConnect app (free)
- Historical data logging
- Excellent UK support network
- Integrates with other Victron gear
Sizing Your MPPT Controller
Choosing the right size MPPT controller depends on your solar panel wattage and battery voltage. Here's a simple guide:
100-150W Solar (Single Panel)
Recommended: Victron SmartSolar 75/15
Perfect for weekend warriors with one flexible or rigid panel
200-300W Solar (1-2 Panels)
Recommended: Victron SmartSolar 100/20 or 100/30
Most common campervan setup - excellent for extended off-grid stays
400W+ Solar (Multi-Panel)
Recommended: Victron SmartSolar 100/50
Full-time van lifers with maximum roof coverage
Important Note
The numbers in the controller name (e.g., 100/20) mean: 100V maximum panel voltage / 20A maximum charge current. Always leave headroom for expansion and ensure your panel voltage doesn't exceed the controller's rating.
Installation Best Practices
Do
- Mount in cool, ventilated location
- Use correct cable sizes (check voltage drop)
- Install inline fuses on all cables
- Connect battery first, then solar
- Configure battery type in settings
Don't
- ✕Mount in direct sunlight or hot locations
- ✕Use undersized cables (causes power loss)
- ✕Connect solar panels before battery
- ✕Exceed maximum voltage rating
- ✕Leave on default lead-acid settings for lithium
Professional Solar Installation
We install complete solar systems including panels, MPPT controllers, mounting, cabling, and commissioning. Every installation comes with:
- Victron SmartSolar MPPT controller
- Professional roof mounting
- Waterproof cable entry glands
- Marine-grade cabling
- Inline fusing and protection
- VictronConnect app setup
Get in touch for a free quote and professional installation by the Volt Vans team.