When it comes to off-grid or backup power your battery bank is the heart of your system to keep everything operating even when there is no power generation. When there is power available however you need to safely put it into your batteries. Most times the power type available is not directly compatible with charging the batteries. This is where some of the world’s best charge controllers come in. Today we’re looking at the different Victron charge controllers and when and why they are used.
At the most basic level, a charge controller is a device that regulates the flow of energy to a battery bank from its power source. Using sensors and programmable computer algorithms, charge controllers constantly monitor both the flow of energy and the charge of the batteries. The goal is to provide the correct power to properly charge the specific type of battery. The charge controller is also designed not to overcharge. Applying the wrong charge can damage batteries.
Victron Energy is a Netherlands-based electronics company that’s been working to provide power solutions for battery-based systems since 1975. This global organization offers nearly 1,000 different products for both on- and off-grid applications. This includes inverters/chargers, autotransformers, solar power systems, and, most notably, charge controllers and battery management systems.
Victron got its start in marine off-grid power systems but has since spread worldwide. It is well known for providing high-quality off-grid power control products.
When picking a Victron charge controller, you need to select the right type for your power source. Batteries can be charged from almost any electrical source but the power needs to be properly adjusted to charge properly. Here are the basics of the different varieties.
If you are building an off-grid solar power plant you need a way to get solar power to charge your batteries. This is accomplished with a solar charge controller. Solar charge controllers come in two primary types, PWM and MPPT. PWM stands for pulse width modulation and in general, is a much simpler but far less efficient way to control solar. Victron however builds some of the best MPPT charge controllers available.
MPPT stands for maximum power point tracking and represents a “smart” solution for solar power systems. MPPT controllers use sophisticated technology to constantly determine and match the output of your solar panels to the proper level of input to charge your battery bank optimally.
This is done by modifying the voltage on the panels, which can often be significantly different from the panels’ nominal output. By using MPPT, solar users can greatly improve their efficiency, especially during cloudier or colder weather.
MPPT units also allow for much higher voltage panels to be used. When operating at much higher voltages you can use smaller wires and get better low-light efficiency.
Victron MPPT charge controllers offer fully programmable functionality to set them up properly for your unique battery needs. Many of them can operate on both 12V and 24V battery banks and some can even do 48V. This makes them very popular for marine and RV solar power solutions.
Victron’s MPPT charge controller size is denoted by two numbers with a / between them. The first number represents the panel voltage that can be applied and the second number is the amperage it can pass through. For example one of the most popular charge controllers is the 100/50 unit. This unit can input 100 volts of panels and pass 50 amps to the batteries.
Suggested Reading: If you choose a Victron SmartSolar, check out our programming guide.
In some cases, you may need to use a DC power source to charge up a DC battery bank. This is where DC-DC Victron charge controllers come in handy, like the popular Orion model. These units can charge between DC systems of the same or different voltages.
Most frequently, these systems go in boats or other vehicles where a starter battery and alternator charge a deep-cycle house battery. Victron’s Orion regulates this current while providing Bluetooth control and monitoring capabilities.
When using a lithium battery bank it’s best not to connect it directly to an alternator even if the voltages match. The reason is that lithium charges so much faster that it can actually burn out the alternator. Some alternators have means of controlling their output but they must be dedicated alternators for charging the house batteries.
The simplest solution is to use a DC-DC unit that allows you to regulate the charge rate so that you do not damage the alternator. The DC-DC unit also automatically detects when the alternator stops and prevents the vehicle’s batteries from draining.
A DC-DC unit can also charge between different voltages. Say you have a 24V system for your house batteries but a 12V system for your chassis. A 24/12 charge controller can charge between the two voltages.
Many battery systems have a way to charge from an AC power source. This could be 120 or 240V in north America or 230V in the rest of the world. This AC power can be from the power grid or a generator.
A Victron charge controller like the Blue Smart and Phoenix are both well suited to this task and like the MPPT and DC-DC are programmable to the specifications of your battery bank needs.
These charges allow you to safely regulate the energy from a typical wall outlet, ensuring you don’t overcharge your deep-cycle batteries. This can be useful for at-home situations like charging some vehicles or boats.
Inverter chargers are a convenient combination of components for those who need to use both AC and DC power from their batteries. At the most basic level, an inverter changes DC electricity (like the power stored in your battery bank) to AC, which powers most typical household appliances, electronics, and other items. However, an inverter charger can both invert from DC to AC and convert AC to DC to charge.
Victron charge controllers like the Multiplus or Quattro are the top choices in this category. These sophisticated devices can detect when shore power (general AC power from the grid) goes down. It can then seamlessly switch to batteries. These are fully programmable units and offer extensive options for additional power flow control and relay outputs. These units also have hybrid inverter functionality with offers power mixing not available with most other inverter chargers.
These inverter chargers are some of the most popular and reliable types on the market and have been used in every type of off-grid power system.
There’s no one-size-fits-all answer to picking the right size charge controller. Like many aspects of your electrical system, it’ll vary based on the size of the system and the amount of power it’s receiving. In general, the larger the charger the faster your batteries will charge but do not exceed more than half the rated capacity of the battery. For example, one 100Ah battery should not charge faster than 50 amps.
Generally, having a charge controller that’s not the exact right size isn’t a big problem, especially for those with a Victron charge controller.
Systems with a too-small charge controller will simply waste any energy produced over what the controller can handle. While this isn’t the most efficient, it’s also not dangerous to your batteries or electrical system.
Having too large of a charge controller can also cause issues. Many charge controllers have minimum energy levels they need to receive to operate properly. As a result, lead-acid batteries hooked to an oversized charge controller can boil or even explode. Lithium batteries like Battle Born’s won’t charge and could also accrue damage.
On top of that, a too-big charge controller will also cost more than necessary, sometimes significantly so. No one likes to waste money, and that’s especially true when investing in a power system.
For those investing in an often expensive and sophisticated power system and battery bank, a charge controller is a must-have. While different applications require different types of devices, there’s no better choice overall than the high-quality, diverse models of Victron charge controller. No matter what power source you’re using, these Victron products will ensure your batteries charge safely, protecting them and keeping the lights on for years to come.
We know that building or upgrading an electrical system can be overwhelming, so we’re here to help. Our Reno, Nevada-based sales and customer service team is standing by at (855) 292-2831 to take your questions!
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2 thoughts on “Beginners Guide to Victron Charge Controllers”
I have a small shop, small guest house and my house on 6+ acres in Texas want to be off grid on all 3 with Victron equipment.
Hi John! Our technical sales team would love to help you configure a system that meets your needs! You can reach them at (855) 292-2831 (M-F 8:00am-4:30pm (PST)).