Can Car Batteries Get Wet? (The Science Behind It)

Car batteries are sometimes exposed to moisture and water droplets or other liquids.  Batteries can be exposed to wet conditions without much worries because of the external case of the battery. The case is mostly completely sealed same to the terminal feed-troughs.

Car batteries can get wet because it is protected by a waterproof external case which is sealed safely. The same applies for the terminal feed-troughs. However, repeated exposure of the battery terminals to water and moisture leads to corrosion and rusting of the terminals. The battery should not be immersed fully in water for a long time as water is likely to discharge it too. 

Can Car Batteries Get Wet? 

does rain affect a batteryIf the battery casing is not sealed properly, water is likely to leak into the batter. When water leaks through the battery casing, it causes rapid oxidation of any metals contacts inside the battery. Oxidation causes an increase in electrical resistance.

There will be a reduction of performance of the pack at high currents. Moreover, water also damages battery management circuitry.

The corrosion of battery terminals is very common in most vehicles which not only comes from wet conditions but also other chemical processes. You can read our guide on how to clean corroded car battery terminals here.

Causes of Battery Malfunctions in Wet Conditions

Temperature – Temperature has a significant impact on battery life and performance. Most car batteries use a liquid electrolyte solution to hold a charge, which is affected by hot or cold weather. While it takes extremely low temperatures to freeze a battery, cold reduces the solution’s ability to transfer full power (which is why it can be hard to start a car in winter).

There’s a misconception that buying a battery with a higher CCA (cold cranking amp) rating will remedy this, but since vehicle computers regulate the amperage required for startup, it actually won’t make any difference. Use a battery heater instead (you can check out this Zerostart Battery Blanket on Amazon) – it’s like a toasty jacket that will keep your battery warm and reliable all winter.

Humidity- Often, humidity usually presented during heavy downpours cause corrosion around the battery connections. This may or may not affect the functionality of the battery and its internal components. It may result in a car battery growing weaker during rainy seasons affecting the traffic flow, electrical accessories operations and charging systems.

Also, hot weather can cause batteries solution to evaporate to thin air causing them not to hold a charge for long. You will notice a rotten egg smell from the Sulphur in the solution.

A common practice is to refill it with water to equalize the evaporation. What’s recommended is you use deionized or demineralized water. Always take your car to the garage for checkups for it to last longer ad work more reliably.

You can also read our other guide: Best car battery brands

Speed– I have first – hand experience of this, I used commute around my hometown. During the rainy season, there is usually lots of traffic, especially in the evenings. People working 8 – 5 jobs leave the office almost the same time running away from the rain.

Because of the long hour’s traffic and heavy rains, most cars get stuck on the road since the batteries have gone down. If your car does not have a powerful engine, you might need to call for help.

Other drivers decide so as not to be caught on the road by the rains that often causes traffic to slow to a crawl even on major highways, they decide to speed home. Amid poor visibility and tension, drivers tend to speed off overworking the engine. In this case, the battery is not able to full charge as expected. This problem is common with old cars.

Modern automotive have the capability to power and alternate speed to the maximum, control and maintain good charging energy. Passengers vehicles are fitted with speed governors thus the battery reserves are limited at very low speeds.

Worn-out belts Have you had a car brake on emergency and make a sharp squeaky sound? This means the belt drive system might have some problems which can go unnoticed during the sunny season. Cooling or lubricating with water may have damaged the belts that drive the alternators causing a squeak when the car is overloaded, braking or stopping. It might make it difficult to navigate the steering on turnings too.

Also read: How to make a snow foam car wash

Bad weather conditions – Cold temperatures accompanied by rains can be blamed for a weak battery. A lot of colds certainly affects the electrolyte contained in batteries cases. If you are wondering if car batteries can wet on top, Some engine seals are poorly donewater (with minerals) can collect at the top of the battery compartment and form a short circuit across the battery terminals.

Can water short a batteryThere will be power draining from the battery due to the accumulation of water. Cables and connections that are kept clean and dry work best and these considerations have led to alternative battery placements. Batteries placed under seats have gained popularity with most car models since the battery is kept safe at all times.

Please not the only water that can short a battery is ionic and not pure water which does not conduct electricity.  Rain barely kills car batteries.

Un roadworthy vehicles – There is a myth that a car should last 6 years because its performance during this time is perfect. However, it all depends on how you treat your car parts. Multiple recharge and discharge of cycles damage any battery life span. When driving most guys prefer to use car batteries to charge electronics like their phones but this aggravates damaging the battery.

Of course, a battery can maintain a charge while the engine is on, but once it’s off electronics draw directly from the battery. And in this case, if you forget and leave your electronics charging overnight or for a long while in the car, the battery will be drained. To avoid such occurrence, always remember to turn off headlights and interior lights to save on the energy when done driving.

In case your battery is about to die, check on the dashboard if the battery warning light indicator alert is on. This means that you should be ready for a replacement. Another way to take note of your battery dying is your car electronics interiors and locks suddenly stop to work. You should always check for such indicators.

Because it’s expensive to replace a new battery, one would opt for a second-hand battery without knowledge of how much life span it’s still left with. Mechanics are out to make money and they might sell old battery which is full of dangerous chemicals. Old dead batteries should be disposed properly to avoid mechanics and auto spare supplies from recycling them.

Alternative components – At times we find faults to blame the car battery when the car refuses to start. It could cause other components with similar signals. A faulty starter motor will make a click when you turn the key that sounds similar to a dead battery.

If the alternator fails, the battery won’t recharge when the engine is on, leading to a no-start condition. Clogged fuel injectors or worn-out spark plugs can be a problem, and corrosion on the battery terminals, which p. Fortunately, it’s easy to clean with a wire brush or steel wool.

With the popularity of all-electric vehicles soaring, there’s a good chance your next car will be powered entirely by batteries.

Lewis James

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