Overcoming Range Anxiety: practical ways to maximize an electric boat's range and runtime
Thanks to rapid advances in battery and boating technology, boat buyers no longer need to choose between sustainability and performance, making electric boats an easier choice for more people. However, similar to other electric transport options, the range of an electric boat is always a key consideration, especially if there are limited charging options for you out on the water! This article covers electric boat range anxiety and options to overcome potential range issues, so you can make the switch to electric with confidence.
What is range anxiety?
Since ‘range’ refers to the maximum distance a vehicle can travel on a single battery charge, range anxiety, as applied to boating, is the fear that your electric boat will run out of battery power before you are able to recharge it, leaving you without battery power out on the water. While there are many ways to avoid this scenario, the fear alone could make boaties feel they need to constantly check their batteries, or even stop them from moving to an electric boat in the first place.
How Do You Overcome Range Anxiety?
First, it is important to note that running completely out of battery power on the water is a rare occurrence and unlikely to happen if the electric boat is used responsibly. Most electric boats on the market are designed for specific applications, and have range and runtimes to match these use cases. Larger boats with power on board can be used to charge electric tenders and RIBs, and marina berths have electrical connections with many installing dedicated charging infrastructure—and this is growing at pace. In fact, the number of charging locations for electric boats around the world is the reason the adoption of electric boats is expected to be faster than that of their on-land counterparts.
While electric boat range could understandably be an area of concern, here are three recommendations to follow to help overcome any potential range anxiety:
Choose the Right Electric Boat
Plan your Trips Well
Maximise your Electric Boat’s Range and Runtime
1. Choose the Right Boat:
If you’re looking for an electric tender or RIB for short trips to transport family, friends and supplies to and from your mothership, for inner harbour fishing, swimming, or watersports, then a boat with a minimum of 10 nautical miles range and runtime longer than 1 hour is recommended. Like the range and runtime of most vehicles, the actual limits are very dependent on the weather conditions and how the vehicle is used - see below for more details on this.
An electric boat’s ability to get up onto the plane quickly, accelerate quickly, and efficiently use its power in all conditions, are key factors in determining how far an electric boat can travel on a single charge. When it comes to choosing an electric boat for use as a tender, you’ll want to look for a light-weight aerodynamic boat with as many of the below features as possible:
Power and weight balance:
To ensure your electric tender or RIB performs optimally and safely, it is essential it has the appropriate power output for its weight because insufficient power will lead to increased energy consumption. A 3-4m tender or RIB carrying 2 people on average will require around 15kW of power (20hp equivalent). If however, you intend to carry more than 4 people or heavier loads in your boat regularly, you may need to look at a different tender/RIB size and power mix.
Inboard configuration:
An electric boat with an inboard configuration (engine located inside the boat’s hull) operates more efficiently as its centralised weight and lower center of gravity reduces resistance in the water, particularly in rough conditions. This is unlike outboard-powered boats that have their engines mounted on the transom at the back of the boat.
Lithium Iron Phosphate (LiFePO4) batteries:
LiFePO4 batteries have a very high energy density, meaning more power in less weight, and therefore requiring less energy to move through the water. They are fast charging meaning less down-time, and are significantly lower maintenance, longer lasting and more resilient than other battery types. For more information on why you should choose a boat with LiFePO4 batteries, please read our article Top 5 reasons why Lithium Iron Phosphate (LiFePo4) is the best battery for your electric boat.
Informative display:
The boat’s display should allow you to track your energy consumption by showing:
The battery charge/discharge rate so you can monitor the charging process.
The boat’s traveling speed so you can drive efficiently.
The remaining estimated range and runtime based on the current speed and battery charge level.
Jet propulsion:
Jet systems can deliver faster acceleration with fewer energy losses compared to other types of propulsion. To learn more about this, please read our guide to Electric Boat Motors.
A portable charger:
It is important that the batteries can be charged from outside of the boat, whether from a dock or tender garage so you are not limited in charging locations. To do this, you will need a suitable charger, a cable with the appropriate plug, and a charger connection.
Efficient charging:
Ideally, the electric boat’s battery should take no longer than 4 hours to charge from 20-99% so you can have more time out on the water!
For a detailed guide on what features to look for when choosing an electric boat, please see our buyer’s guide.
2. Plan Your Trips Well
The best way to ease any range anxiety is to be prepared with a good plan before you leave on your trip. Here are some tips to ensure you never find yourself short of charge out on the water:
Remember the rule of thirds: Use a third of your charge to get to your destination, a third to get back to your mothership (or to a charging port), and always have a third in reserve. If you plan as if 30% of your battery capacity is 0% and follow that plan, you will leave plenty in reserve.
Check the distances between locations (online or on your mothership’s GPS navigation). Plan this ahead of time and remember to not significantly change your route spontaneously!
Remember that if you are traveling in rough conditions, traveling at inefficient speeds, and carrying a lot of supplies or people, your energy consumption will be greater than usual and therefore your range and runtimes will be less than usual.
Identify potential charging locations before heading out. These locations typically include marinas and any designated charging stations.
Learn how long your battery takes to charge to specific levels so you can incorporate waiting time into your plan. .
Always check your battery level state of charge (SOC) before departing.
Charge when stopped, don’t stop to charge- ideally do top-up charging when you are in-between trips so your state of charge is above 80% for your next trip. Check access to charging sources as most electric boats can be charged using standard AC power, so they can be charged on the mothership in-between uses, as well as at marina berths via a 16A socket.
And simply keeping an eye on your battery level state of charge and always erring on the side of caution means responsible boaties will have nothing to worry about.
3. Maximise your Electric Boat’s Range and Runtime
An electric boat’s estimated range and runtime is typically stated on the manufacturer website. However, it is not always clear that these claimed times are based on standardized testing conditions only, and the ‘real world’ range and runtime will vary based on actual use.
In addition to asking for any conditions or assumptions that manufacturers have provided around their claimed range and runtime numbers, here are some other practical tips to avoid unnecessary energy consumption and maximise your electric boat’s range and runtime:
Drive efficiently:
Drive at planing speed: wherever possible, driving at planing speed allows the boat to glide over the water with reduced drag. Once the boat is on the plane, it typically becomes more energy-efficient.
Minimise idling: avoid unnecessary idling or prolonged periods at low speeds as idling consumes energy unnecessarily. When the boat is not in use or when waiting, consider shutting off the propulsion system to conserve energy.
Avoid excessive acceleration: avoid sudden bursts of acceleration as it consumes more energy from the battery. Gradual and smooth acceleration will be more energy-efficient to get to planing speed.
Ask for recommendations from the electric boat supplier on the most efficient speed ranges and other energy-saving techniques tailored to your boat's design and propulsion system.
Drive to the conditions:
Check the weather forecast and try to avoid rough conditions. Choppy seas, strong headwinds, heavy rain, extreme temperatures, and strong tidal currents mean more energy is required to move the electric boat.
Manage on-board weight:
Avoid unnecessary weight as this requires more energy to move the boat through the water. Remove unnecessary equipment, supplies, or personal belongings that are not required for the trip.
Maintain proper battery health:
Maintaining proper battery health is critical. When batteries are not properly maintained, they will degrade and deliver less range over time. It is recommended that you follow the manufacturer's guidelines for battery charging, discharging, and storage. Choosing resilient and low maintenance batteries can be key to preserving your electric boat’s range and runtime.
With a little extra care, you can experience the benefits of going electric without compromising your time out on the water!
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