Everyone knows that water and electricity shouldn’t mix. But that doesn’t mean every contact between water and your batteries will end in disaster. You have even less to worry about if you’re using top-of-the-line lithium batteries. So let’s take a closer look at what you need to know to answer the crucial question — can lithium batteries get wet?
Lithium Batteries Versus Lead-Acid Batteries
Before we explore lithium batteries and water, we must understand some critical differences in the technology they use to store and release energy.
Lead-acid batteries operate using two lead plates, a positively charged anode and a negatively charged cathode, submerged in an electrolyte solution (typically sulfuric acid). When you draw power from the fully charged battery, negatively charged sulfate ions move to its negative lead plate. This plate gives up its electron and produces electricity.
While charging, the process runs in reverse, with the sulfate ions regaining their negative charge and returning to the electrolyte solution.
This electrolyte solution must maintain the correct balance of water and acid. This means owners of many basic lead-acid batteries must regularly open their batteries and top them off with distilled water. Unfortunately, this unsealed design limits how you can mount the battery, as these batteries require adequate venting.
In some ways, lithium batteries work on the same principles — a cathode, an anode, and an electrolyte solution. When you draw energy from lithium batteries, lithium ions move across the electrolyte solution to the cathode, giving up their electron to produce electricity. As with lead acid, the process reverses when charging.
However, unlike lead-acid batteries, lithium ones are made entirely sealed. This means the electrolyte solution remains perfectly balanced for the battery’s life, with no maintenance or regular check-ins required. This sealed design prevents any battery components from getting out — or in our case, anything from the outside from getting in. This not only protects them but makes lithium batteries inherently safer than lead-acid ones.
Can Lithium Batteries Get Wet?
The short answer is sometimes and will depend on the manufacturer’s design and quality. Our Battle Born batteries are fully sealed and getting wet is not a problem. However, they should not be submerged as this can short out the terminals and put excessive pressure on the case.
As noted above, lithium-ion batteries are sealed cells, meaning there’s some inherent protection from water. This isn’t the case with unsealed lead-acid batteries, where water can much more easily penetrate.
However, the amount and duration of water exposure also matter. Most lithium batteries will stand up fine to a little rain or an accidental splash. But while they’re somewhat water resistant, submerging any battery in water may result in damage. Water that infiltrates lithium batteries can reduce performance or even render the battery inoperable over the long term.
Therefore, while you should take steps to protect lithium batteries from excessive water, they should be OK with exposure.
What Happens When Lithium Batteries Get Wet?
Depending on the quantity and duration of water exposure, the answer is usually (and hopefully) nothing! Once again, the sealed design triumphs against occasional water exposure, keeping the critical parts of the battery safe from harm.
However, extended exposure can lead to damage, particularly to sensitive parts like the terminals. More serious issues can result if water reaches the battery components themselves, causing potentially dangerous chemical reactions.
If a battery is submerged, current will be able to flow in the water between the terminals. This will discharge the battery as well and could potentially damage it. While our BMS might protect a short-term submersion, it’s still possible that damage will occur.
Fresh Water Versus Salt Water Contact
Not all water impacts batteries in the same way. Batteries exposed to salt water will suffer more damage and degraded performance than batteries exposed to similar amounts of fresh water.
It comes down to the dissolved salt in the water, which not only corrodes battery parts and cables but is also more electrically conductive than fresh water. When touching battery terminals or certain other parts of your battery, this can deplete the charge without you even noticing.
Can Lithium Batteries Explode Under Water?
When exposed directly to water, the lithium within lithium batteries can, unfortunately, have a dramatic and potentially dangerous chemical reaction. They combine to form combustible hydrogen and lithium hydroxide, both of which battery owners should avoid.
To have this happen, a battery would have to be fully disassembled and the cells would need to be cut open. This, of course, would completely destroy your battery before it ever got wet. If you drop a properly-sealed lithium battery into the water, it should not explode.
Can You Recharge Wet Lithium Batteries?
Generally speaking, if your battery has some spray on it or is damp recharging it should not be a problem. If it is sitting in water or submerged never apply a charge, however.
If you believe water has damaged your lithium battery, you shouldn’t attempt to recharge it. Instead, safely dispose of it.
Can You Leave Lithium Batteries Outside?
This is one of those critical issues where there’s a big difference between can and should. Once again, it comes down to lithium batteries’ sealed design and general hardiness.
With no exposure of internal components to the outside world, there’s no inherent danger in them sitting outside. Lithium battery components also work well at very high or low temperatures, meaning normal weather probably won’t damage them. Therefore, you should be fine if you leave your batteries outside for a short period.
However, you shouldn’t leave them exposed to the elements for an extended time if possible. After all, most people invest significant money in their batteries and want them to last as long as possible. Protecting your battery from rain, wind, water, and extreme temperatures will help extend your battery’s life, saving you money and hassle over the long run.
What Precautions Should I Take to Keep My Lithium Batteries From Getting Wet?
While you shouldn’t obsess over a little water, there are some basic precautions you can take to keep things dry and minimize the issue.
If possible, install your battery in a covered location shielded from water, like an indoor part of a boat if it has one. Otherwise, you can build waterproof battery boxes or compartments to provide protection from all but the most extreme water exposure.
Also, it may sound simple, but avoiding using your boat or other vehicles during rain or other precipitation can go a long way toward keeping your batteries dry.
How to Waterproof Your Batteries
Those looking to go a step further in providing extra protection for their batteries can also waterproof them. In addition to secure dry-box-style battery compartments, you can wrap batteries tightly or coat them in waterproof materials. These can offer an additional layer of protection as long as terminals and other critical parts of the battery remain exposed and usable.
Pro Tip: Ice fishermen build battery boxes to keep their batteries warm and dry.
How Safe Are Lithium Batteries on a Boat?
Under normal circumstances and with basic care, lithium marine batteries are extremely safe to use on the water. In fact, they’re the top option for those who need marine batteries with extensive storage, quick charging, and the ability to operate in nearly any condition. Compared to lead-acid batteries, you have more options for mounting them. You also have less risk of trouble from rough seas.
Plus, as we’ve discussed, they have a lower risk of water-related damage or issues. While many have heard scary-sounding stories of lithium battery fires, these generally only occur with other lithium battery chemistries. Our lithium-iron phosphate design is one of the most stable and safe forms of lithium-ion chemistry.
Don’t Panic If Your Lithium Batteries Get Wet
Can lithium batteries get wet? The answer is yes! However, while it’s not the best thing for them, getting your lithium batteries a bit wet on occasion isn’t the end of the world. Thanks to their sealed design, they can withstand quite a bit of water before suffering any severe or lasting damage.
Still, don’t submerge your lithium batteries in water. Also, dry them as soon as possible when they get wet. At the end of the day, lithium remains the top choice for marine use, and its ability to deal with water is a noteworthy part of that.
Want To Learn More About Electrical Systems and Lithium Batteries?
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