Lithium batteries are becoming more popular in the marine world, and not just on the bigger sailboats and yachts. Many people are switching to lithium for their bass boats, houseboats, and even to power kayak fish finders!
Lithium batteries offer many benefits over lead-acid ones, including better performance and longevity. They weigh a third to a half of what lead-acid batteries weigh, and they can be recharged faster.
Converting your boat to lithium batteries may seem daunting, but we’ll guide you through the process step by step to help you understand how to make the switch.
Step 1: Figure Out What Components You’ll Need
This can vary based on the type of boat you’re using and how you’re using your batteries. In some cases, you may be able to use lithium batteries that are drop-in ready to replace your lead-acid ones, but most of the time, you’ll need to switch out some other components as well. Let’s take a look at what you might need depending on your setup.
The first thing you’ll need to do is figure out how many lithium batteries you’re going to need. You’ll likely want 12V batteries, but deciding the necessary number will depend on your boat type and setup.
You’ll need a cranking or starting battery to start up the main engine. Most people continue using a lead-acid for this, as not many companies make a starter lithium battery.
However, lithium is the better choice if your boat is a sailboat, houseboat, or another type with a house bank. They’re also great for trolling motors.
So how many do you need?
Trolling motors are pretty straightforward. A good approach is if you have a 24V trolling motor, get two 12V lithium batteries, for a 36V get three 12V batteries plus one more to run components on or to be your “bank.”
For house banks, you’ll need to figure out how many amp-hours (Ah) you need to operate your vessel. To do this, you can make a list of all the devices and appliances you use, their wattage, and how much time you use them during a day.
For example, let’s say you have your instrument lights (3 watts) on for 12 hours a day. Multiply the wattage by the hours, and you’ll get 36 watt-hours. Then, divide that by 12 volts, and you’ll get 3Ah.
Add up everything on your list to get your total daily Ah usage. Then you’ll need to decide how many days’ worth of power you’ll need between charges. Once you have this number, you’ll be able to figure out how many batteries you’ll need to cover that.
You’ll most likely need to get a new charger and/or charge controller because lithium batteries have a higher charging voltage than lead-acid batteries. What you get will depend on how you charge your batteries and your current setup.
If you have solar panels, your solar charger (MPPT) likely already supports lithium batteries, so you’ll need to check that. If you use the engine’s alternator to charge your batteries, you’ll need a DC-DC charger. There are also combo charge controllers that support both DC-DC and MPPT. No matter which type you need, double check that the charger you choose supports lithium batteries.
When you purchase lithium batteries from Patriot Power Source, they come with a lithium-specific charger. However, it’s a 10 amp charger and is entry-level. This may be okay for smaller boats, but for those that are out cruising for multiple days at a time, you’ll want something that’ll recharge your batteries faster. It’s great to have as an emergency backup, though!
You’ll need a battery monitor, so you always know how much battery you have left. You can use a basic meter or something that displays more data, such as battery temperature, current usage, estimated remaining runtime, etc.
If you purchase a Patriot Power Source bundle kit, you’ll get a battery percent meter with your lithium batteries.
For sailboats and houseboats, you’ll likely need an inverter. This allows you to plug in your devices to a regular household 110V power outlet.
You’ll need to figure out the total wattage of the devices you’ll be using simultaneously to decide on the wattage size that you need. It’s always a good idea to add an extra 10-20% as a safety buffer. This total will tell you the minimum wattage inverter that you can use.
Modified sine wave inverters can damage electronics, so be sure that you choose a pure sine wave inverter if you plan on using laptops or other electronics.
Step 2: Placement
Most marine vessels already have a place for batteries. However, lithium batteries can’t get wet, so you may need a water-tight box, especially if you’re using it in a kayak to power your fishfinder. You also may need a bigger battery box since lithium batteries are taller than lead-acid ones.
You’ll usually be able to make your current battery storage work, though. Check out the space and take measurements to be certain everything will fit before you get started.
Step 3: Bench Test
It’s always a good idea to test everything to make sure it’s working before installing it.
Use a volt meter to test the batteries. Once you’re sure they’re working, you can hook them up to the inverter and test it with something small like a hair dryer or electric razor. Of course, what you test and how you hook it up will depend on your vessel.
Make sure to read all the manuals to hook everything up correctly and test out all the components you’ll be using.
Step 4: Installation
If you’ve already tested everything, you should know how everything hooks together. If you’ve already had to position everything to get it tested, this step could be pretty simple.
Once you have the batteries in place, make sure they won’t be able to move around. Most battery boxes and house banks provide enough support for the batteries, so this isn’t a problem, but you should strap them down if it is.
The next step is to hook up the wires. Patriot Power Source batteries can be wired in parallel or series with up to four batteries. They also include a new wiring kit, so you should be all set with everything you need.
You’re done! Now it’s time to get out on the water and enjoy all the power and benefits you’ll receive with your new lithium batteries.
Give Patriot Power Source a call if you have any questions or concerns about lithium batteries for your boat at