Why Lithium Marine Batteries the Best Choice For Your Boat In 2019

Posted September 09, 2019

How do you power life on a boat?

Obviously, you'll use a generator and solar power is a great way to save money and be kinder to the environment. But regardless of the method you use, you'll need a place to store that power.

For that, you'll need a battery.

Some people steer away from using lithium marine batteries because of that scary price tag. But don't let that number scare you away. There are so many benefits of lithium batteries — many of which actually lower the cost over time.

Let's take a look at the top benefits of choosing lithium marine batteries for your boat.

1. More Usable Amp-Hours

Both AGM and lead-acid batteries should be discharged no more than 50%. Thus, even if you have a battery bank that provides 345 amp-hours, you can only use 172 of them before needing to recharge.

Lithium batteries can be 100% discharged. To promote a longer lifespan, it's a good idea to only discharge them to 80%. Even then, a 300 amp-hour battery bank will still provide you with 240 usable amp-hours — significantly more than the other types of batteries.

2. Life Expectancy

The life expectancy of lithium batteries is quite impressive. When discharging them to 80%, you can expect them to last more than 2,000 cycles.

AGM batteries can only be expected to last about 1,000 cycles. Plus, you have to be diligent about not draining them more than 50% to keep them in tip-top shape.

3. Weight

You already know how important weight is on a boat. A heavier boat means burning more fuel to get where you're going. Plus, a boat that's too heavy isn't safe.

Lithium marine batteries are a great choice when you're concerned about your boat's weight. Lithium batteries weigh about half as much as lead-acid batteries and about a third less than AGM batteries.

This weight savings doesn't even take into account the difference in usable amp-hours and life expectancy. You'll require fewer lithium batteries to get the same number of usable amp-hours.

This means that not only are lithium batteries smaller and lighter, but also you'll need fewer of them to perform the same job. The savings in weight (and space!) just keeps adding up.

4. Stable Voltage

If you've spent time on boats, you've probably noticed the unstable voltage. Things are going along just fine until something new kicks on — like the refrigerator or microwave. The lights might dim a little as there is a drop in voltage while the battery struggles to power the new addition.

A lithium battery maintains a higher resting voltage — usually about 13.2 V compared to 12.6 or 12.8 for a fully charged lead-acid battery. As the lead-acid battery is discharged, the resting voltage begins to drop. And, of course, there is that drastic drop with a new load as we mentioned.

The resting voltage of a lithium battery doesn't change much regardless of load or how much it has been discharged. This helps appliances to run more efficiently. In fact, you may find that they require fewer amps or less time to do the same amount of work.

You also won't need to have any additional "starting" batteries. The lithium batteries will be able to handle the heavy draw of a new load just fine.

5. Fast Charging

Discharging the batteries more means that you're going to have to sit around charging them for longer, right? Wrong.

You may be familiar with watching your battery charge up to 90% nice and snappy...and then take hours to fill the remaining 10%. This is due to the internal resistance of a battery and the phases of charging.

Lead-acid batteries follow a 3-phase cycle. The first push speedily charges the battery up to 80-90%. Then, because of the high amount of internal resistance, they require a long absorb phase. The lead plates inside simply can't absorb the energy fast enough.

The third phase involves a painfully slow trickle charge that means it often takes hours to fill up that last little bit. You also have to fully charge them each time to properly preserve their lifespan.

With little internal resistance to get in the way, lithium batteries skip that painfully slow absorb phase. They go zipping all the way up to 100%. On top of that, you don't have to fully charge them if time doesn't allow. If you only have an hour available to charge your battery, you can take advantage of it.

6. Hold Their Charge

On top of charging quickly, the lithium battery's self-discharge rate is much lower than that of lead-acid batteries.

This is the charge that the battery loses simply because it is not in use.

7. Less Wasted Energy

Lithium batteries are capable of maintaining and using about 99% of their energy.

New lead-acid batteries lose about 15% of their energy due to resistance and other factors. As they age, the percentage of usable energy shrinks even more.

8. No Maintenance

Lead-acid batteries don't seem like much work. You just have to add water now and again.

Until you switch to lithium batteries and you don't have to do anything. It's amazing how much work just remembering to water your batteries can be!

Are Lithium Marine Batteries Right for You?

Once you account for all the benefits of lithium marine batteries, they actually aren't as expensive as they seem. They last longer, put out more power, and lose less energy, meaning you will buy fewer batteries over time. Plus, they weigh less and require less energy to charge.

This makes the upfront investment worth it for most people.

Ready to make the switch to lithium batteries? Check out our line of marine batteries to power your adventures.

Still have questions? Feel free to contact us! We're happy to lay all your doubts to rest.