Adding more solar controllers can help optimize energy harvesting and charging. But doing it the right way takes some electrical know-how.
The Core Benefits
What exactly do you gain by using multiple solar controllers? Here are the main advantages:
Increased Charging Capacity
Adding more controllers lets you channel more solar power into your batteries. Each controller has a limit to the amperage it can handle. So two 50 amp controllers allow 100 total amps of charging, vs a single 100 amp controller maxing out at 100 amps. More controllers = more potential charging capacity for your batteries.
Redundancy
With multiple controllers, a failure of one won’t completely knock your solar system offline. Redundancy provides peace of mind when you’re off the grid or camping remotely. Having a spare onboard as a backup could save you from dark days if your only controller dies.
Flexibility
Adding a controller lets you easily integrate more solar panels and experiment with different types. As long as each string going into a controller is compatible, you can mix and match panel voltages, wattages, and orientations.
Optimized Performance
If some panels are shaded but others are in full sun, multiple controllers let you isolate the sunny panels to deliver maximum output. The shaded ones won’t bottleneck the system if on a separate channel.
Key Setup Considerations
While the benefits are compelling, properly setting up multiple controllers requires some electrical know-how:
Compatibility
Ensure your controllers work with each other and your battery bank. Using the same brand often helps, but the key is matching:
- Battery voltage (12V, 24V, etc.)
- Max input currents and wattages
- Charge profiles to avoid under/over-charging
Wiring
How you connect the controllers makes a big difference in performance:
Parallel – The outputs connect to a shared battery bank. Allows for expanded capacity and redundancy, but the controllers must stay in sync to avoid conflict.
Independent – Each controller has its own solar input and dedicated battery output. Isolates the channels to avoid conflict, but requires separate battery banks.
Most RVs use parallel wiring for simplicity, but independent setups can make sense for larger systems. Proper fusing either way keeps things safe.
Cost
There’s no doubt about it, multiple controllers impact your wallet. You’ve got the controllers, large wiring to handle increased loads, and potentially installation costs if you don’t DIY. It’s an investment, but usually pays off in the long run.
Smart Automation Solutions
The latest smart controllers make setup and control much easier. Here are some top options to consider:
Rover MPPT Controller
The Rover line from Renogy has advanced MPPT tech and smart connectivity options. The Bluetooth module lets you monitor and adjust settings right from your phone. And the smart tracking algorithms maximize solar harvesting. Just wire additional Rovers in parallel as needed to scale up.
Victron SmartSolar MPPT
Victron Energy makes high-end equipment for energy systems. Their SmartSolar controllers have robust MPPT charging and can link together via built-in Bluetooth. The Victron GX device acts as a central hub to monitor and control each unit. A premium choice for larger, more complex installations.
ALLPowers MPPT Controllers
ALLPowers offers an affordable line of MPPT controllers with remote display units. While not as full-featured as some competitors, they provide the key functions at a lower cost. Great for adding supplementary controllers on a budget.
Wanderer Li MPPT
The Wanderer Li from Renogy is an expandable lithium battery system with integrated smart MPPT solar controllers. Additional solar modules and batteries can be added modularly. The system can automatically manage charging from multiple controllers, simplifying paralleled setups. Convenient for DIY installs.
Battle Born Solar Controller
Battle Born Batteries offers the BBC-100 smart controller designed specifically for their LiFePO4 deep cycle batteries. It allows combining multiple units via CAN bus, with automatic load balancing between battery banks. Clean modular integration if you’re already using their batteries.
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