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Inverters and chargers are different devices, but they're both vital for the electrical systems on houseboats.
An inverter converts DC power from your houseboat's batteries into AC power for use with 120-volt appliances. A charger converts 120-volt AC shore power to DC power and monitors the charge level of your batteries. Some chargers regulate DC to DC charging from solar panels.
In this article, we'll cover the primary features of inverters and chargers, along with the differences and similarities between them. We'll describe how they work, what they're for, and why they're necessary on a houseboat. Additionally, we'll overview two of the best houseboat chargers and inverters on the market today.
We sourced the information used in this article from the manufacturers of chargers and inverters, along with general technical guides to electrical power and marine battery systems.
What Does a Houseboat Inverter Do?
Simply put, a houseboat inverter converts DC (direct) current into AC (alternating) current. There are multiple ways to turn DC into AC power, but an inverter does it without moving parts. In the United States, the most common use of inverters is to convert stored 12-volt DC power into 120-volt AC power.
What is Direct Current?
Direct current is power that flows in only one direction. Direct current, at least when compared to alternating current, is relatively safe. This is why (at low voltages) you're not likely to get shocked by a car battery, but you can definitely be shocked by terminals on the alternator, which generates alternating current.
While we're on the subject of alternators, let's go over another way to convert direct current into alternating current. In the past, a large DC electrical motor was connected directly to a large alternator. When the DC motor spun the big alternator, it used mechanical energy to produce alternating current.
These bulky mechanical systems have been phased out of small-scale use, and you can see why a solid-state inverter can be hugely beneficial on boats.
Why Convert Direct Current to Alternating Current?
Alternating current has several distinct benefits over direct current. Instead of moving in one direction, alternating current bounces back and forth. Essentially, it moves less—but it carries a charge (and thus, its energy) much further and more efficiently.
Alternating current is used in household appliances. Certain appliances that require direct current simply use a small transformer on the plug. It's far easier to convert AC to low-voltage DC than it is to turn low voltage DC into high voltage AC. This is one reason why municipalities use AC. In other words, it's more robust.
We convert DC into AC aboard houseboats because it allows us to use virtually any consumer appliance but draw off of battery power instead of grid power. This power is stored in DC, as current flows out of a battery in only one direction, like a pipeline.
DC power from batteries can run many devices, but it's limited by the type of plugs available on most items. Most laptops don't come with a 12-volt plug, and you'd be hard-pressed to find a decent 12-volt coffee maker. So, instead of giving up these luxuries, we simply convert the power to AC using an inverter and install regular household outlets around the boat.
What is a Houseboat Charger?
A charger is used to charge DC batteries with AC power. You can't charge a 12-volt marine battery directly off the grid. A battery only has one polarity, so attempting to charge it with a plain high-voltage alternating current is a losing proposition. The battery might even explode.
So before charging the battery from a 120-volt source, we need to do two things: First, we need to convert the alternating current to a single-polarity direct current. Then, we need to step the voltage down from 120 volts to 12. A charger performs both of these functions.
In a sense, a charger is just an inverter in reverse. It's usually cheaper to produce and purchase, too, as it's slightly less complex. Chargers perform additional functions, such as monitoring the charge level in the batteries.
What are Houseboat Chargers Used For?
Houseboat chargers allow you to charge the battery bank on your boat from a shore-based source. Chargers can also be used to charge batteries while the engine is running, as houseboat charges usually handle both processes from the same system.
Houseboat chargers also monitor the charge level of the batteries and automatically disconnect them when they're full. This is a useful safety feature, and it also allows you to run appliances on grid power when docked to avoid depleting your batteries.
Automatic Cutoff and Charge Control
So, why do chargers have automatic charge control? Think back to the pipeline model we mentioned earlier. The grid has unlimited power, but a battery can only hold so much—so picture it like filling a tank. When the tank is full, you need to shut off the source, or it'll explode.
Batteries work much the same way, and unregulated charge controllers have led to numerous fires and explosions over the years. But with automatic charge control, you're safe from overcharging, and you'll get to monitor the status of your charge as it progresses.
Do Houseboats Need an Inverter and a Charger?
Yes, houseboats usually have both an inverter and a charger. This allows you to safely charge and monitor your batteries, and it also allows you to use normal household appliances with your battery power. This is why houseboat living is more comfortable than other kinds of boats, which may have limited AC outlets and battery storage.
DC to DC Charging Systems
Chargers are also used to monitor and control DC to DC charging, like from an engine or solar panels. These systems are required for onboard power generation of any kind. DC to DC chargers can often be used with multiple 12-volt sources, such as the engine, a set of solar panels, and a wind turbine.
Best Chargers for Houseboats
We went out and found two of the best chargers for houseboat battery banks. These devices are a good representation of what you're likely to find in a production houseboat, and they can be a great upgrade for existing obsolete systems.
1. Charge Pro 10 Amp Battery Charger
Charge Pro designs and builds heavy-duty marine charging devices that protect your batteries and grid power source. This particular unit is certified waterproof, and ideal for harsh marine environments. It's approved for freshwater and saltwater use, and it's capable of charging both 12-volt and 24-volt systems.
The Charge Pro battery charger runs on 120-volt AC power, which is what you're most likely to find at any marina in the continental United States or Canada. This charger can charge flooded and AGM marine batteries, and it comes equipped with a microprocessor-powered charge control system for safety.
2. Renology DCC50S 12v-12v Battery Charger
Here's a great charge controller for 12-volt power sources. The Renology DCC50S DC charging unit is ideal for use with solar and wind systems aboard houseboats. This model is popular with land-based applications, as it's compatible with AGM, GEL, flooded, and lithium batteries.
The unit is not waterproof, but it's less vital to protect it from water due to its low voltages. 12-volt DC is less hazardous than 120-volt AC when exposed to water, though it still poses a hazard and should be kept dry. This unit comes with bluetooth monitoring and automatic trickle charge control.
Best Inverters for Houseboats
Most houseboats come with inverters already installed. But if you want a newer, more efficient, and safer replacement, here are a few options to consider. It's especially important for inverters to be safe, so we chose only high-quality models.
1. Renology 2000-Watt Pure Sine Wave Inverter
Here's a small inverter that's ideal for situations where you don't need a whole lot of AC power. The Renology 2000-watt pure sine wave inverter is great for retrofitting vintage boats with modern electricity. This inverter offers 2,000 watts of AC power from a 12-volt DC battery bank. Pure sine wave inverters are superior to older types, as they're more efficient and reliable.
2. Magnum Energy ME Series 3100-Watt Marine Sine Wave Inverter
Here's a heavy-duty marine inverter that's designed to be wired into wall plugs on your houseboat. This Magnum Energy ME Series 3,100-watt marine inverter also serves as a 6,000-watt charger, which makes it ideal for tight spaces where you need one device to perform both functions. This high-quality inverter is designed specifically for boats and utilizes efficient and harmonic sine-wave technology.
