Battery Equivalents and Replacements

Can You Jump Start A Car Safely In The Rain?

Most cars and trucks feature 12V DC electric systems and onboard batteries or battery packs that are used, among other tasks, for cranking the main engine used for propulsion.

However, from time to time, batteries tend to fail for various reasons and those failures don't always happen on a clear, sunny day. On a contrary, when things go bad, usually more than one thing goes bad, raising the question if one can safely jump-start a car in the rain?

Published: March 28, 2022.

rain windshield

Car Battery Voltage and Water

High moisture levels and water don't go well with high voltage - water, especially mixed with various salts and dirt can conduct electricity, not as good as wires, but good enough to make serious problems when that occurs.

However, car electric systems are DC systems using just 12V and as long as the battery is more or less dry, there should be no issues with the moisture in the air and jump-starting the car.

So, when jump-starting the car in the rain, be sure that the battery is as dry as possible and that water doesn't drip off the cable onto the battery and its terminals.

How to Safely Jump Start a Car in the Rain?

When jump-starting the car, there are several options, including:

Jump-Starting a Car Using Jumper Cables and a Second Car

In order to jump-start a car in the rain using jumper cables and two cars, one with a bad battery and another one with a good battery, first, attach the red cables to the red battery terminals (positive) and then attach the black cables to the negative battery terminals.

Let the engine of the second car run a minute or two in order to build up a "surface" charge on the bad battery.

Crank the engine of the car with a bad battery and remove the cables in the reverse direction (black wires/negative battery terminals first, red wires/positive battery terminals second).

If required, go to the nearest authorized car dealership or workshop to check the car's electric system, including the battery.

Jump-Starting a Car Using Jumper Cables and a Fully Charged Battery

This method is very similar to jump-starting a bad car with a good car - instead of connecting the bad battery to a good battery of a running car, one connected a bad battery to a good battery using jumper cables.

Note: it is highly recommended that a good, fully charged battery is also a starting battery (or dual-purpose battery), preferably with a larger capacity.

First, attach the red cables to the red battery terminals (positive) and then attach the black cables to the negative battery terminals and let the batteries stay connected for a minute or two - this will allow some "surface" charge to be built on a bad battery.

Crank the engine and remove the cables in the reverse order.

Charge the good battery as soon as possible using a suitable battery charger.

Again, if required, go to the nearest authorized car dealership or workshop to check the car's electric system, including the battery.

Jump-Starting a Car Using a Lithium Car Jump Starter

Lithium car jump starters are a very convenient way of jump-starting the cars when the battery fails.

Each lithium car jump starter may feature certain specifics regarding the car jumping procedure, but generally, one has to connect red wire with the positive battery terminal and black wire with the negative battery terminal.

After turning ON the car jump starter, it will analyze the battery and if possible, send some charge to the battery in order to build some "surface" charge.

After analysis and other tasks (if any), the lithium car jump starter will signal the user to crank the engine after which the wires should be removed in the reverse order.

Again, if required, go to the nearest authorized car dealership or workshop to check the car's electric system, including the battery.

cars in the rain


Long Story Short: If You wonder if it is safe to jump-start a car in the rain or not, well, it can be done safely or as safely as possible - keep the battery dry and don't let the water drip from the cables onto the battery.

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- Car Jump Starter

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