Inverter Charger Kits: Frequently Asked Questions
- What are some of the functions of the major components in an AC Input & Output system?
A stand alone inverter is a device that connects to a battery bank and typically has an AC outlet on the side of it. This device draws DC power from the battery bank and inverts it to 120V AC power. These are practical if your largest load is a computer or an instant pot.
A charger, or converter, does the opposite of what an inverter does. It takes 120V AC power and converts it into power that can be used to charge a battery bank. These are typically used with stand alone inverters as a means of charging the battery when plugged into shore power.
An AC passthrough system is a glorified power strip, that takes shore power and feeds it directly to the outlets or AC devices in your rig. Stand alone inverters, chargers, and transfer switches can work in conjunction with an AC passthrough system.
A transfer switch is a device that prevents power from one AC source (maybe inverted battery power) from touching power from another source (like shore power). A typical transfer switch would be installed with the AC loads and outlets as its output, with one input being an inverter’s output and the other input being a shore power connection. This would typically be installed to have a preference of shore power over inverted power, when both options are present.
An inverter/charger combines and inverter, a charger, AC passthrough, and a transfer switch into one device. These are typically used for applications when more than 2000W is needed, like running microwaves, induction cooktops, and air conditioners. Combining everything in one unit, makes for easier installation and more control over the AC portion of the power system.
- How do you go about designing an AC input/system? What’s the first step?
When designing your AC Input/Output system, design it for the loads you have now, and the loads you think you might have in the future. Unlike a battery bank or a solar charging system, you can’t efficiently expand an inverter system. Without taking it all out, the system you start with, is the system you get. With this in mind, you should also look at the relatively small price differences between different ratings of inverter kits. For example, to go from 2000VA to 3000VA is only roughly a 10% price increase. Design your inverter system around your largest 120V AC load. If your biggest load is only going to be an Instant Pot, or computer, we like to use the Victron Phoenix 1200VA inverter with a separate IP22 30A charger. If your biggest load is microwave, blender, or hairdryer, we like the Victron Multiplus 2000 inverter/charger.
Learn more: 2000VA or 3000VA, a Multiplus Dilema
- What’s the difference between converters and inverters?
A converter (or charger) takes 120V AC and turns it into something that can be fed onto a battery bank to charger it. An inverter does the opposite. It takes power from a battery bank and turns it into 120V AC.
- What kind of programming do these devices need?
Chargers need to be programmed with charging parameters specific to the battery chemistry being used. Proper programming allows your batteries to be charged up to 100% State Of Charge without overcharging. It also allows your batteries to recharge (or Rebulk) when batteries have been drained while being plugged into shore power
An inverter just needs to be programmed with a cut out voltage, to stop drawing power from the battery bank when the battery bank reaches a certain low voltage or state of charge. For many customers, AM Solar provides free programing of all Inverter/Chargers before we ship the device.
- How do I monitor my system? When operating an AC input/output system, what input is needed from the user?
There are a few settings that will be adjusted regularly. First, the Mode. This is where you can turn your inverter ON and OFF, or put it on Charger Only or Inverter Only modes. The functions of the Charger Only and Inverter Only modes are self explanatory and are primarily for testing, not something that would be necessary for day-to-day use. The ON and OFF modes are more important. When an inverter is running, with no loads, it can draw up to about 20W of power. Left ON all day, and this energy draw will be roughly equivalent to the daily production of 160W of solar panels. To conserve energy, turn the Inverter/Charger to OFF mode when not charging or needing AC power.
Another important setting to keep an eye on is the input current limit. Most vans are wired for a 30A AC shore power connection. If you are plugged into a 30A shore power connection, make sure your input current limit is dialed all the way up, so you can enjoy a maximum charge rate and full passthrough for all of your loads. But, if you connect to a smaller AC power source, like a 15A outlet on the side of your friend’s house, you’ll want to dial the input current limit down to 15A. If you don’t, you’ll risk popping a breaker in your friends house, which will be annoying, and leave you without shore power until the breaker gets reset.
- What if I want to run a 240V mini-split?
If someone thinks they need 240V AC in van, we first try to talk them out of it. Most of the time, it’s cheaper and easier to find 120V AC versions of the appliance than it is to build a power system that can support that appliance. But, if it has to be done, we typically recommend an autotransformer or dual inverter system. Neither of these options is simple or low priced.
- What if you need more power than your shore can deliver?
Victron Inverter/Chargers, have a feature called PowerAssist. If you are plugged into 15A shore power outlet, but you need 20A of AC current for your loads, the PowerAssist feature will take that maximum 15A of current from shore, and combine it with 5A of AC current inverted from your battery bank.
- What is an Inverter/Charger Kit for RV Solar Installations?
An inverter charger kit for RV solar installations is a system that combines the functions of an inverter and a charger into one unit. It allows you to convert DC power from a battery bank into AC power for use in an RV, and also to charge your RV’s batteries when connected to an external AC power source. This dual functionality makes it an essential component for RV owners with moderate to high 120V AC energy consumption habits. Inverter/Charger kits come with the inverter/charger, plus all the power cables, communications cables, lugs, fuses, breakers, remote meter, etc. that you might need for a successful installation in your particular vehicle.
- Why Do I Need an Inverter/Charger in My RV?
If you want 120V AC power without being plugged into shore power or running a gas generator, you need an inverter. If you require more than about 1000W of inverter capacity and want a faster charge than 30A DC, you will likely want an inverter/charger, rather than a separate inverter and separate charger unit.
- How Do I Choose the Right Wattage Rating for the Inverter/Charger for My RV?
Choosing the right inverter/charger rateing depends on your power requirements. Calculate the total wattage of the appliances and devices you plan to run simultaneously. The inverter/charger should have a continuous power rating that exceeds this total wattage. Additionally, consider the surge power rating for appliances that require more power at startup and compare this to the surge rating of the inverter options. For example, if you want to run a microwave or blender, a 2000VA inverter will work. If you want run an air conditioner, or multiple loads, get a 3000VA inverter. If you want to run two air conditioners, get a 5000VA inverter, or dual 3000VA inverter system.
- What is the difference between Volt-Amps (VA) and Watts (W)?
The long technical answer gets into concepts like power factor, where the sine wave of the voltage may not line up perfectly with the sine wave of the current, but for the vast majority of users, there is no need to make a distinction between the two. Volts x Amps = Watts… Some inverter manufacturers prefer to use VA and others prefer W. In most cases, a VA number is about 80% of what the W would be (e.g. a 2000VA inverter can loosely be called a 1600W inverter) but this small difference in VA and W numbers is rarely large enough to influence system design decisions. If it is, you’re probably cutting it too close.
- Can I Install an Inverter/Charger Kit Myself?
DIY installation is encouraged if you have the time, ambition, tools, and ability to follow instructions. However, if you’re not confident in your abilities, it’s best to hire a professional to ensure safe and proper installation. See our blog: DIY VS. PROFESSIONAL INSTALLATION: WHAT’S BEST FOR YOUR RV SOLAR SYSTEM?
- What Maintenance is Required for Inverter/Chargers?
Maintenance is generally minimal:
-Regularly check and clean connections.
-Ensure the unit is free from dust and debris.
-Monitor the system’s performance through any built-in diagnostics or external monitoring systems.
- How Do Inverter/Chargers Work with Solar Panels?
In off-grid applications, inverter/chargers don’t interact with your solar array at all. The inverter/charger just draws power from the battery bank or puts power on it. The inverter/charger can do this while the solar array is charging or not charging the battery bank. They are parallel systems that do not interact with each other. You can have a 3000W solar array in bright sun, with a 300W inverter or a 300W solar array and a 3000W inverter. It doesn’t matter.
- What Safety Features Should I Look for in an Inverter/Charger system?
Nothing AM Solar sells is going to be unsafe, but systems can be set up in an unsafe way.
-There should be no exposed 120V electrical conductors.
-Cables between the battery bank and the inverter/charger need to be properly sized (e.g. for 12V battery banks, 2/0 or greater for 2000VA, 4/0 or greater for 3000VA)
-The ground wire should have continuity from the shore power inlet, to the inverter, to the loads.
-There should be circuit protection between the battery bank and the inverter/charger (e.g. for 12V battery banks, 300A fuse on a 2000VA, 400A for a 3000VA)
-Ground fault protection (GFCI) should be used on all external outlets or outlets near sources of water.
-AC wires should be correctly sized (e.g. at least 10ga on 30A, at least 6ga of 50A).
- Can I Run All My RV Appliances Using an Inverter/Charger?
This depends on the capacity of your inverter charger and your battery bank. High-energy appliances like air conditioners and microwaves may require a larger system. It’s crucial to understand the power requirements of your appliances and match them with the capacity of your inverter charger. Systems can certainly be designed that will run all of your appliances. It’s just a matter of how long they will run before the battery bank is depleted.
- What’s the Difference Between a Pure Sine Wave and a Modified Sine Wave Inverter Charger?
–Pure Sine Wave Inverter Chargers: These provide power similar to what you get from the utility grid, compatible with all modern electronics and sensitive equipment. Graphing the voltage over time gives you a smooth sine wave with just one frequency.
–Modified Sine Wave Inverter Chargers: Less expensive but may cause issues with certain sensitive electronics and can be less efficient. Graphing the voltage over time gives you a stairstep wave form with many harmonics.
- How Long Do Inverter Chargers Last?
The lifespan varies based on quality, usage, and maintenance. Generally, a good quality inverter charger can last between 5 to 10 years. Regular maintenance and proper usage can extend this lifespan.
- Can I Connect Multiple Solar Panels to My Inverter/Charger?
With off-grid systems, you never connect panels to an inverter. Panels are connected to a charge controller that feeds to a battery bank, and the battery bank supplies the inverter/charger.
- What Happens to the Inverter/Charger When My RV is Plugged into Shore Power?
When plugged into shore power, the inverter/charger switches to charging mode, using the external AC power to charge your RV’s batteries. It also passes through AC power to run your RV’s appliances. With some inverter/chargers, AC passthrough power can be mixed with inverted battery power.
- Do Inverter/Chargers Improve the Efficiency of Solar Panels?
Inverter/chargers in off-grid systems just give you AC power or charge your battery bank with AC power. They don’t have anything do with your solar panels.
- What Is the Impact of Weather on Inverter Chargers?
Extreme weather conditions can affect the performance of inverter chargers. High temperatures can lead to overheating and reduced output. It’s important to install the inverter/charger in a location protected from direct exposure to harsh weather, including temperature extremes and moisture.
- Are Inverter/Chargers Compatible with Lithium Batteries?
Many modern inverter chargers are designed to be compatible with lithium batteries. However, it’s important to check the specifications of both the inverter charger and the batteries to ensure compatibility. Lithium batteries require special charging parameters that may not be compatible with some chargers.
Temperature Sensor for BMV-712
Support from AMSolar is definitely 5 stars. 1st line of support for Victron equipment provided through distributors. AMSolar likely one of the best when it comes to RVs.
Tom B