Tighten car battery terminal. What Are Battery Cables Used For?

Checking battery leads and connections

A faint click or total silence when the starter key is turned usually means that the battery is almost or completely flat. If, however, the battery is fully charged, the trouble is probably in the circuit between the battery and starter.

Either way, lack of power is preventing the starter motor from working. though there may be just enough current to work the solenoid. which makes a faint click or chatter.

If you suspect the circuit, look first at the battery-terminal connections. Unless they are in good condition, the current cannot flow through them properly. and sometimes not at all.

The most common types of connector are a clamp that fits around the battery post, or a cup that fits over it. The clamp is secured by a bolt; the cup by a screw into the top of the post.

The Ford type has a flat cable connector bolted to a flat battery post.

The mating surfaces of both connectors and battery posts must be free from dirt and corrosion.

Any green or white powdery deposits must be removed, and the metal surfaces beneath brightened.

Remove these deposits also from the battery carrier or any other metal parts. they are very corrosive.

If cleaning the terminals does not cure the trouble, examine the earth lead. particularly where it is attached to the body or chassis. and clean if necessary. There must be a bare-metal contact for proper earthing.

Some cars have another earth lead between the engine and the body or chassis. Be sure to examine it also.

Look also at the starter motor and solenoid for loose connections, which can cause sparking. This is a fire hazard in any circuit, but becomes an even greater one in the battery-starter circuit, which has around 300 amps flowing through it.

Make sure that the battery is not loose in its mounting, or electrolyte may spill out and cause corrosion.

The battery leads can also work loose, or the case may crack through being bumped about. A loose clamping bracket can touch the live terminal of the battery and cause a short circuit.

Removing battery connectors

Clamp or cup connectors can be removed after unscrewing the securing bolt or fixing screw. But take care if the connectors have been tightly fixed on.

Avoid prising them off or trying to twist them loose. undue force and damage the battery posts or their seal with the top of the case.

A screwdriver can be used to force apart the jaws of a clamp connector.

The Ford type is removed simply by unscrewing its nut and bolt.

Similar precautions should be taken when refitting. Do not hammer the connector down over the post.

When you use a spanner on a clamp or connector bolt, take care to keep the free end away from the car bodywork, where it can cause a short circuit. even is the engine is switched off.

How to clean battery terminals

Use hot water and domestic soda to start removing the powdery deposits that may form on terminals. But be sure that none of this solution finds its way into the battery cells.

The battery posts can be ‘brightened’ with a wire brush or emery cloth.

Do not, however, remove so much metal that the cup or clamp becomes a loose fit on the post.

If that does happen, some metal can be filed from the jaws of the clamp, or the sides of the cup can be squeezed in a little, so that it grips the post once more. Alternatively, replace a cup connector with a clamp type.

Refitting the connectors

Smear a thin coat of petroleum jelly (not grease) on the mating surfaces of both the battery posts and connectors before refitting, to deter corrosion and ensure good conductivity.

Ideally, the cup or clamp should be an easy push fit over the post. Tighten the securing bolt or screw enough to stop the connector moving on the post, but do not overtighten.

If a cup-connector screw does not tighten because the thread has been stripped, put a length of solder wire into the hole to fill it partly.

tighten, battery, terminal, cables, used

A self-tapping screw should then cut a new thread with enough bite to hold the screw firm. Or simply use a larger self-tapping screw.

How to Change the Battery Clamps on Your Car

I went to remove the battery from my 2004 Honda Accord the other day, and in the process of removing the battery cables, the connector broke off!

Those old cheap connectors had to go. You shouldn’t have to put up with that either. Follow these steps to replace the battery clamps on your car.

What you’ll Need:

Gather together the following items to perform this simple repair.

  • 10mm wrench
  • wire brush
  • sandpaper
  • terminal cleaner brush
  • battery cleaner spray
  • diagonal cutters and/or dremel tool
  • new battery clamps – I use and recommend these ones


These are the steps to take to replace the battery terminal clamps:

  • Disconnect the negative, then positive battery cables.
  • Cut, or grind, off the old connector.
  • Clean the exposed battery cable with a cleaning agent.
  • Attach new clamps using a 10mm wrench.
  • Reconnect the battery cables starting with the positive side first.

Now let’s go into more detail on each of these steps.

Step by Step Procedure to Change Battery Terminal Clamps

Step 1: Disconnect the Battery

Start by disconnecting the battery cables from the battery. Start with the negative cable first. It may make things easier to remove the battery from the car while you work on the clamp replacement.

Step 2: Remove the old Connectors

If you have plenty of battery cable to work with, use a diagonal cutters or wire cutter to cut the old clamps off. If not (as in my case), use a grinder or dremel to cut off the old clamp.

The metal clamps are typically fairly soft, it tends to not take too much grinding.

Remove both the positive and the negative battery clamps.

Step 3: Clean the Battery Cables

The battery cables likely have some amount of corrosion on them (generally a result of either over or under-charging the battery).

Use a corrosion cleaning agent such as battery cleaner spray.

For more details, check out this article on cleaning the corrosion off of your battery.

Use a wire-brush to scrape off the corrosion. Also use the wire brush or battery terminal cleaner brush on the battery terminal to clean off any corrosion there as well. Use a rag to wipe the wire clean.

Repeat for both the positive and negative battery cables.

Step 4: Acquire and Attach New Battery Clamps

I like these battery clamps for the following reasons:

  • They are stiff, unlike lead or copper clamps that deform every time you take them on or off.
  • Made of brass which is a good conductor.
  • Military-style clamp.
  • Plenty of room to clamp down on the battery post. My old ones were ‘maxed out.’
  • These come with the corrosion-resistant pads (red/green).

The connector clamps onto the battery cable using two 10mm bolts. The threads are in the clamp, so you don’t have to worry about losing the nuts.

Put the corrosion-resistant pads onto the positive (red) and negative (green) battery terminals. Disassemble the clamp.

Place the battery cable in the clamping portion.

Use a 10mm wrench or socket to tighten down the clamping bolts.

Repeat for both the positive and negative battery terminals.

Step 5: Reconnect the Battery Cables

Put the battery cables back onto the battery posts. Start with the positive side first.

Tighten them down with a 10mm wrench or socket.

The new clamps will last for quite some time.

Loose Battery Terminal Symptoms

Symptoms of a loose battery cable are the vehicle not starting, the vehicle’s electrical system is flickering, or the battery is not taking charge. Usually, this is caused by a loose battery terminal.

A loose battery cable can lead to recurrent battery failure. A few symptoms can indicate that a battery cable is loose.

Sluggish Battery

One of the most common symptoms of a loose battery cable is a sluggish battery. If your car battery is not taking a charge from the alternator like it used to, it may be due to a loose battery terminal.

Vehicle Is Not Starting

Another common symptom of a loose battery cable is the vehicle not starting, and it could be due to loose battery terminals.

This can also make it appear that the battery has been drained, but this is usually not the case.

A loose battery connector can cause excessive electrical resistance and hinder the battery from charging properly, preventing the vehicle from starting due to insufficient power in the battery.

Flickering Electrics

The least common symptom is if the car has power without the engine spinning the alternator, and the electrical system in the vehicle starts acting erratically; it could be due to a bad connection to the battery.

Troubleshooting How to Fix Loose Battery Cables

If you suspect that your battery terminals are loose, you should first check the connections. Ensure that the terminals are tight and that there is no corrosion on the terminals or wires.

Loose Battery Cable

The good news is that tightening loose battery connectors is relatively easy to accomplish if one has the ability to use a wrench.

Locate the battery in your car. The vehicles battery is most likely located under the hood but could also be found in the trunk on some makes and models.

Try to rotate the battery terminals and see if they are loose. If the terminals are loose, you will need to tighten them.

You can use a wrench, socket wrench, or block wrench to do this. Sizes can vary from 10mm to 14mm.

My car requires the 10mm socket to secure or disconnect batteries terminals, but you might need a bigger socket on your vehicle.

tighten, battery, terminal, cables, used

Just be careful not to over-tighten the terminals, as this can damage the battery or the terminal itself.

Corroded Battery Terminal

If a cable does not seem loose, it won’t eliminate the possibility of a weak connection, and corrosion is normally seen on such components.

It is necessary to clean the battery terminal so that the metal meets the battery pole material.

In the case of corrosion on the terminals, you will need to remove the corrosion from the terminal.

I prefer to use a wire brush to remove the corrosion, but some sandpaper is a great alternative to remove most of the corrosion from the battery pole and terminal.

Bad Car Battery

If the connections look good, the next step is to test the battery’s voltage.

You can do this with a voltmeter.

Connect the voltmeter to the batteries positive and negative terminal, and check the reading.

If the batteries voltage is low, it could be due to loose battery cables or a bad battery. If the voltage is high, it could be due to an overcharging alternator.

Replace The Cable Terminals

Disconnect the negative battery terminal, then disconnect the cable from the corresponding terminal.

Loosen each of the nuts and bolts holding on a terminal clamp in place, or cut the terminal off the wire.

Apply some dielectric grease to the wires to prevent the connection rusting, and put the new terminal on the wires.

Depending on the terminal you bought, clamp it together using a pair of plyers or screw the bolts using a wrench to tighten the terminal to the wire.

Will A Loose Battery Cable Kill The Battery?

Loose cables don’t directly drain the battery – but they can create circumstances that lead to it.

Current can’t ‘escape’ through the cable, even if it has a loose connection.

However, it could cause other issues. The loose connections mean the alternator isn’t charging the battery correctly. Thus it can lead to a discharged battery.

In rare cases, the intermittent current might create a glitch in a system. This might lead to a parasitic drain.

How To Fix A Loose Car Battery Connection

Tightening up the clamps is a straightforward job. You’ll need a correctly-sized socket or spanner.

Turn the clamp’s bolt clockwise (righty-tighty) until it’s as tight as possible. Repeat this for the other terminal.

Don’t let the metal spanner or ratchet touch both terminals at the same time! This will create a dangerous short circuit and could hurt you and your car.

If this doesn’t fix your problem, the best option is to take your car to a professional. They can clean the terminals and clamps for you. This prevents any mistakes that could harm you or your vehicle.

The price will depend on what exactly needs doing. Many mechanics might simply fit a new battery and clean the clamps. This often makes all the problems go away.

Concluding Thoughts

Loose battery cables are often a very simple fix: retighten the clamps.

If you find a lot of rust at play, you should instead go to a mechanic. If you’re confident and aware of the risks, it’s possible to clean the terminals yourself.

Fixing any problem sooner rather than later is beneficial in the long run. It prevents further damage and, thus, has less impact on your wallet.

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Ben is an IMI-qualified light vehicle technician from England with experience in a fast-fit garage. He aims to help drivers worldwide with common automotive problems. You’ll often find him working with his 1.2 Vauxhall Corsa. It may have a tiny engine, but in eight years it’s never once let him down!

How To Replace Melted Battery Terminal?

Replacing a melted battery terminal is very easy if you follow the correct instructions step by step. By following the process, it can be done in 1 hour under 20 or 30 bucks.

Step 01: Safety Check and Removal

Firstly, check the battery terminals and the cables to ensure they are entirely disconnected from the machine. Then unbolt both of the terminals from the battery cable ends.

After that, use a wire brush or sandpaper to clean up the corrosion from the battery. You can use acid and water solutions to neutralize the battery, or you can always buy a battery terminal cleaner spray from a nearby hardware store.

Step 02: Buy a New and Good Quality Battery Cable Terminal

Suppose you want a battery cable terminal to last a long period without melting and avoid the extra cost. In that case, later on, you must buy the best possible cable terminal available to you.

tighten, battery, terminal, cables, used

We always prefer Copper Compression Terminals as they are not cheap quality as Lead Battery Terminals.

Step 03: Seal the entire Connection

Sealing the whole Connection with a heat-shrink tube will help to prevent it from corrosion. It is not expensive, but it will greatly help in the long term.

Step 04: Replacing the Battery Terminals

This part is a little complex for some people, but if you got the right tools (Hacksaw, pliers, ratchet set, and wrench set), the process becomes much more manageable.

Use pliers to hold the terminal while you hacksaw it from the cable. Cut half inches of each cable and clean it with a wire brush. Then slip the cable tubing over the cable.

Step 05: Tighten the Bolts and Test

After inserting the main cables through the compression nuts, put the bolts on the battery terminal and tighten them properly. But do not over-tighten them, as they can cause some damage afterward.

That’s it, and you can test the battery now with a multimeter to check the continuity of electricity through the cables.

How To Prevent Your Battery Terminal From Melting?

Most of the damage happens because of a lack of care, but with proper care and following some steps, anyone can make their battery last longer.

It is almost impossible to use one battery forever, but it is possible to use one for a very long time with good care.

Regular Check-Up

Checking your battery once in a while can help you to understand the condition of the battery cable terminals.

So, if you notice any inconsistency around the terminal, you can fix it before it gets worse. Ultimately it will prevent the battery terminals from melting.

Tighten the Bolts/ Nuts properly

A common mistake everyone makes is that they think it’s better to over-tighten the bolts. But in reality, it’s the opposite because when there is too much friction, it will generate heat.

So, to protect it from overheating, plug the bolts accurately. Not too tight, not too loose.

Carefully Use the Jumper Cables

When using jumper cables to start a car or use the battery, look carefully at which cable goes to the positive terminal and which goes to the negative. This little carefulness can remove the chances of melting.

Clean the terminals

Dust and rust can ruin your battery terminals as they are obstacles in between them. So, whenever you notice the battery is dirty, or the metal part got rusted, clean them with a wire brush and polish the surface. It will protect the battery from the unnecessary arc.

Coating and Park under Trees

One of the most helpful prevention methods is using Heavy Duty Metal Protector spray on the terminals. This coating reduces the chance of melting.

Another thing that can help from melting is parking your vehicle under shadow or using a sun reflector on the engine, reducing the heat inside the truck. As a result, the pre-heat won’t be an issue.


People have various questions relating to this topic. We tried our best to answer the frequently asked questions based on the matter below. Hopefully, you will find your answers as well.

How much does it cost to replace a battery terminal?

Battery terminals are much cheaper than an entire battery, so it is always an easy choice to replace the terminal when needed.But it depends if you have the tools already at your home. Because if you don’t, it will cost you extra money to buy the tools.It will cost around 20 for good compression and another 10 for cleaning materials.

Why does the positive terminal get hot?

Positive terminals can get hot for several reasons, such as a defective starter. Broken or damaged starts can create issues while transferring electricity.Another reason can be incorrect contact with the terminal surface, which creates an arc and makes the terminal hot.The positive terminal gets hot because of a faulty alternator because it puts extra pressure on the battery to generate power, and the terminal gets hot.

What happens if a car battery gets too hot?

Extreme heat can cause serious damage to the car, and it is very likely to cause a fire while the engine is still running. It is common to understand that if the battery gets too hot, it will melt the terminals.So, if any terminals melt because of excess heat, it will be the origin of a severe accident, which can cause serious damage to the car.

Can I Use melted battery terminal before replacing it?

The clear answer to that question is “No” unless the terminal’s melted a little. Still, we don’t prefer to use a melted terminal because it can bring bigger problems like accidents or damaging the car, which can cost thousands of bucks.If the terminal is melted slightly, you can use it for a few hours with the risk, but we still suggest not to use it in that condition.

What does a melted battery smell like?

A melted battery will produce Hydrogen Sulfide gas which smells pretty bad and is also harmful to health.It can smell like rotten eggs or sewerage water because these two also contain the same type of gas.It is a toxic gas formulated from the acid inside the battery, and you will instantly notice it because it will have a burning effect on your nose.


Finally, the overall idea is that the main culprit of the problem is heating, even though we are to blame for our carelessness about cable management and not taking proper care.

It is not a very tough job to check the battery condition regularly if someone wants to avoid the situation. Doing a little work, putting the cables correctly, and cleaning from time to time, anyone can save themselves from this problem.

The replacement process is so straightforward and low cost, but some of us avoid that little effort them pay a higher price later after having a bigger incident. It is better to solve the problem before it gets worse.

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