I Accidentally Installed My Car Battery Backward! What Should I Do About It?

We are not perfect creatures. We sometimes do things unexpectedly, like installing the car battery the wrong way. If you are not very familiar with battery installation, you may think it will not do any harm. But, we are dealing here with car batteries which have voltages that may spark anytime when you installed incorrectly.

What to do when you install your car battery backward? Accidents may happen anytime. Some car owners misconnect their array. In this case, the vehicle or the car will not start. If a car battery is connected reversely, there is a fuse that is designed to protect the electronics of the vehicle in case it will blow.

If the car doesn’t have that protection fuse, you need to send the electric current back to the systems of your car, that includes the ECU, transmission unit and more.

When the current flows back through the lights, it’s not going to be a problem. The ECU is not commonly damaged by reverse battery installation. Most ECUs are designed to work against reverse polarity.

Wrong battery installation can pose immediate danger like sparking or electrical blowing. (Learn how to install your car battery the right way). However, modern-day batteries are already designed to keep up with the wrong or reverse polarity. Battery manufacturers have modified this because a lot of car owners have encountered this misconnection of batteries.

Thus, they have designed batteries that can withstand the reverse polarity or will guard users against the hazards of connecting the battery in the wrong polarity.

Steps for Troubleshooting a Car that Won’t Start Because of a Battery Installed Backward

Step 1: See the fuses that are high ampere on your vehicle. Most of the cars use large fuses which can blow and prevent damage to the ECU/ECM. It can be a 40, 60 or 80-ampere fuse and this is rare finds.

When the jumper cables are connected reversely, it may blow a fuse. After replacing the fuse, you can start up the vehicle. It should start up the car, if it doesn’t start, proceed to step 2.

Step 2: Once the blown a fuse has already been replaced, you may still encounter problems in starting the car engine. Your engine may crank but will never begin. When this happens, it is time that you check all the other small fuses. You need to make sure that the ignition system fuse, the ECU, the fuel pump, and immobilizer are still working and in good condition.

Step 3: After checking everything and all the fuses are still good, but your car is still not working, then go this step and do this:

A. The car is cranking, but it won’t start

● See if the plugs are sparking.
● Take a look at the fuel pressure.
● See if the direct injectors are receiving enough power.

B. The car does not crank

● Check the immobilizer system.
● See if the ECU is getting enough power.
● Look if the starter is also receiving power.

Step 4: If all things failed, have an expert mechanic check on your car. These steps are highly recommendable for everyone making a self-diagnosis on their vehicles. You must also remember that you must not let your fuse panel be wet with rainwater or any liquid at all.

The Consequences When the Battery is Connected Reversely

Hooking the battery the wrong way may seem a simple issue, but think again, the electrical damage that it will bring to your vehicle and its accessories may be a lot. Here are some of the consequences that you may incur supposing you have connected the car battery inversely.

● It will blow the alternator.
● It will damage your radios and other accessories.
● It will damage the relays, the computer box, ignition switch or even the
starter if it is engaged.

Does a Car Battery Explode When You Connect it Backward?

If what you mean is to connect the battery terminals in the opposite position or the reverse connection, then yes, it can explode. You can make it more likely to blow some of the diodes and battery components when taken from the battery. It could also mean that there could be no loud explosion but an expensive outcome, perhaps.

But by backward you mean that your battery is connected to the array of the vehicle through a jump start and you made it in the reverse order, then a real explosion could probably happen.

Jumper cables that are placed in the wrong order will result in a tremendous current coming from both arrays. However, if there are no explosion happened internally, then there could be a huge flash and a melting terminal from the location of the last connection. Therefore, to be safe, do not attempt to do it.

What Happens When You Jumpstart a Car the Wrong Way?

All drivers know that they can revive the car battery by jumpstarting it using a car with a charged battery. Car batteries are designed to give the highest electrical current needed to be able to start the engine. It can even be more dangerous if the jumper cables are disconnected.

Here is what could happen:

1. Battery Damage

If you join the positive terminal to the negative terminal of the battery, it will create a massive surge of current to the two batteries. It may heat both batteries quickly, which is not suitable for it. The heat can melt all the essential parts of the cells, both internal and external. Hydrogen gas can ignite and explode.

2. Jumper Cable Damage

The cables use for jumpstarting a vehicle are not expected to carry the significant amount of electrical surge of current. It can quickly heat up to high temperatures. With the high heat, it can quickly melt the cable covers and expose the cables to people.

3. Incorrect Polarity Damage

Once you have incorrectly connected the jumper cables, the electrical system of the vehicle will also be reversed. It can bring irreparable damage to a lot of electronic components of the car like the onboard computers and sensors.

What Could be the Damages Caused by a Battery Installed Backward?

Some of the possible damages that a battery installed backward can have are the following:

● The Connecting Terminals.
● The Battery.
● The Charger.
● The Electrical components of the vehicle.

There you go, you have the following tips and techniques on what to do when you install your car battery backward. Remember that you should always practice with caution, especially when you are working with arrays.

1. Jump Started or Installed Battery the wrong way – youcanic
2. Consequences of Hooking a Car Battery backwards – Car Talk
3. Do car batteries really explode if you connect them backwards? – Quora
4. What Happens If Jumper Cables Are Reversed on a Batter? – It Still Runs
5. What Damage is Caused by Incorrectly Hooking Up the Battery Charger Cables? – Techwalla