A battery bank is one of the costliest components of a PV system, but it grants you independence from the grid and protects your house during power outages. Choosing the right solar charge controller can increase the lifespan of your storage system and decrease charging times. What follows is a ranking of the best solar controllers based on their reliability and efficiency.
What is a Solar Charge Controller?
A solar controller is a device that directs energy from solar panels to a battery bank. It regulates the incoming voltage and current to keep the batteries fully charged. Special algorithms make sure that no overcharging takes place while maximizing the efficiency of the process. An inadequate charge controller or its absence may easily lead to gassing or battery damage. Keep in mind that the system is only as reliable as its weakest component. A charge controller will represent around 10% of the total system costs, so it makes sense to buy one of the best devices. In the long run, it will save you much more by prolonging the lifespan of the much more expensive batteries.
MidNite Solar Classic MPPT 150
This solar controller has a special learning mode – switch it on and the device will start the process of self-optimization to encounter the specific settings that make the charging process more efficient in your particular set of circumstances. As an additional advantage, the user has an option to manually adjust power curves.
- Easily stackable with other MidNite Classic models – you don’t need a special hub to make them function as one big controller
- Ethernet, USB, and RS-232 ports allow you to easily communicate with the device both ways
- 32 MB of data storage capacity is more than enough for a charge controller. This feature also allows you to upgrade the device’s firmware using downloaded files
- Protect your device from marine or dusty environments using a special sealing kit
- Two auxiliary relay outputs. AUX1 may serve as a 12 VDC output or a dry-contact relay and AUX2 as a 12 VDC, logic input, or a PWM signal
Schneider Electric MPPT 80 600
The Conext 80 600 is probably one of the best solar charge controllers on the market in terms of versatility. It is an equally good device for both grid-tie and off-grid systems, as well as for setups with backup power. The Conext 80 600 is a building block – connect together as many as you want for systems up to 36 kW.
- Built-in backfeed and overtemperature protection, as well as protection from input over and undervoltage, output overcurrent
- High efficiency of 96% at 48 V and 94% at 24 V
- A shade tolerant fast sweep MPPT technology
- Very few parts and simple design help to cut installation costs
- Works with positive, negative, and ungrounded solar panel systems
- Supports long strings
Morningstar TriStar MPPT 60
This TriStar solar charge controller from Morningstar is one of the very best in the industry in terms of efficiency. The peak efficiency of the device reaches an impressive 99%, and its power losses are lower compared to other solar controllers employing MPPT technology. The TriStar MPPT 60 is a good option for off-grid PV setups up to 3 kW. It maximizes solar harvest with a proprietary TrakStar algorithm which enables the controller to find the peak power point of the system more rapidly.
- The highly reliable device made by a company with extensive experience and knowledge
- An Ethernet port for an entirely web-enabled interface
- Data logging functionality and 200 days of information storage
- No cooling fans and mechanical relays
- Parallel circuit design prolongs the life of electronic components
OUTBACK FLEXmax 100 AFCI
This model is full of innovative technologies but has been rigorously tested to guarantee reliability. Among other tests, FLEXmax 100 AFCI has successfully passed Highly Accelerated Life Testing (HALT). Rapid shutdown features together with arc and ground fault protection have been integrated into the device to enhance safety and ensure compliance with all the relevant standards. The model’s enclosure protects it from water and dust, meaning it can also be installed outside. Remote programming capabilities give the unit an additional advantage over the competitors.
- The controller constantly tracks the system’s performance and has the ability to store up to 128 days of data
- Easily programmable auxiliary control output
- Up to 6 kW of charging
- Double string configuration helps to minimize BOS
- One of the best price to power ratios in the whole industry
Morningstar ProStar PS-30M Gen3 PWM
Aside from the standard applications such as residential grid-tie and off-grid systems, the Morningstar ProStar PS-30M can also be employed as part of a mobile setup. The key feature of the device is its stability. This is enabled by constant monitoring and self-diagnostics. This solar charge controller is virtually immune to damage from overloading or short-circuiting. It also features reverse polarity protection that doesn’t require mechanical fuses.
- MODBUS protocol for less complicated control, remote access functionality, and charge sync
- Up to 256 days of detailed performance data
- High-resolution LCD with multiple languages support and backlight
- Automatic charge optimization enabled by the remote temperature sensor
- The battery selection process is fully automatic