Can You Put a Car Battery in Power Wheels?

A drained battery on Power Wheels can be frustrating and disappointing. It cuts short, plus now your kid will have to wait for the battery to charge again. A car battery would solve both problems, but can you put a car battery in Power Wheels?

You can put a car battery in Power Wheels. The process is not complicated but getting the larger car battery to fit requires time-consuming modifications to the vehicle. A car battery will not make the Power Wheel faster, but it lets your kid drive longer before the battery needs to be charged.

If you are ready to get started, I will walk you step-by-step through the entire process. When you finish, you’ll be able to install a car battery in a Power Wheel. Let’s begin. 

Take Out the Old Battery

This will most likely be the easiest part of the project. It also seems so obvious that you are probably wondering why I brought it up in the first place. There are two reasons:

• To double-check the color of the positive and negative wires. 
• To measure the space to make sure you have room for the new battery after modifying the battery compartment. You want to be sure the battery will fit.

Now that you have made your measurements, it’s time to move on to the next step—making room for the new battery.

Install the Car Battery

Even in vehicles with room in the back for a battery, people prefer putting them in the front. The vehicle already has the weight of the kids, and additional weight in the back does not distribute the weight equally. 

Making room for the battery is a two-part process.

Make Room for the Battery

Most likely, you will have to cut out the front piece on the vehicle. You are going to need the following:

• Bungee cord or another method to keep the hood from closing while you are working
• A cutting tool for plastic. A Dremel tool will come in handy because the space is small. 
• A piece of sheet metal to make a new grill. Ideally, you want something that has some ridges instead of a flat piece. It needs to be long enough to go around the battery on the front and both sides.
• Screws or bolts to hold the new grill in place
• Drill and screwdriver
• Battery Terminals
• Electrical Pliers

Once you have your materials, it’s time to get started.

1. Figure out a way to keep the hood from falling. A bungee cord should work for practically any vehicle. 
2. Remove the grill if you haven’t already done so. 
3. Cut out the front battery compartment with your Dremel tool. If you have a grinder, it will probably be too big to fit in the space, and a hand-held plastic saw will take forever.
4. Once you are finished, put the battery in place.

Make Sure the Battery Will Stay in Place 

Unless you want the battery to fall out while your kid is driving, you need a way to keep it in place. You will need to make another grill. 

This is especially important—you are not cutting the sheet metal to cover the front. Instead, you are making a three-sided container, almost like a box. The purpose of your first cuts is to make it easier to bend the metal.

1. Measure the front of the battery and then the sheet metal. 
2. Cut slits into the top and bottom of the metal, and a third slit in the middle. Remember, you will fold the metal to create the housing.
3. Bend each side of the metal back at a 90-degree angle. 
4. Next, cut each side, leaving two inches or so. You will fold these two sides to make a flange to attach the sheet metal to the vehicle's battery compartment. 
5. After you make the cuts, but the new grill in place. If you need to make adjustments, mark them, and make your final cuts. Remember to leave a little extra for the flanges.
6. Fold the ends to a 90-degree angle to make your flanges.
7. Make sure it fits. Then drill into the sides or front of the battery compartment, slide the grill in place.
8. Drill holes into the housing and flange.
9. Use bolts to connect the grill to the housing. 

If the battery housing is firmly attached, you have finished the most challenging part of this process. 

Note: These directions assume that your Power Wheel has a lip at the front of the battery housing. If not, you will need to adjust the battery housing.

Hook Up the New Battery

Now that you have finished the hard part, it’s time to attach the battery. This will be straightforward and fast.

Your battery needs to be hooked up to the power wheel, but the motor harness (or coupling) will need to be replaced. Before you snip it off, check the polarity of the wires. Some vehicles will have a black positive, while others will use black for the negative (or red). The coupling will indicate this.

Next, you need to put battery terminals on the wires. Strip each of the wires down a quarter inch or so, feed the exposed wire into the terminals, and crimp them on. 

Time to install the battery. Put it in place and attach the wires to the battery. Tighten them, so they are firmly connected. 

And that’s it. The Power Wheel is ready to go. 

How the Car Battery Will Perform

A common concern is whether the car battery will fry the electronics of the Power Wheels. It won’t because a car battery is 12 volts. The difference is how much power it can hold, not how much power it provides. 

Because of this, do not expect that the Power Wheels will drive faster. This replacement is designed to make the vehicle go longer, not faster. To get more speed, you would need to use a stronger battery. That calls for more modifications.

If your Power Wheels has a 6-volt battery, modifying it to a 12-volt is not impossible, but it isn't straightforward. You are doubling the amount of voltage going to the engine and speed controls. Without extensive modifications, your engine might last longer and run faster, but it won't last as long. And a burned-out engine is going nowhere fast. It might be time to upgrade to a 12-volt Power Wheel.

Can Power Wheels Handle Stronger Batteries?

If your goal is to have a faster vehicle, you need a stronger battery. A 12-volt battery extends the time before you need to recharge, but it does not add speed. To do that, you must be prepared for additional modifications.

First, you are going to have to find additional room for two batteries. You will also need to know how to run batteries in a series. It’s not difficult, but you will need to read up on it or check out some YouTube videos.

Once you have that figured out, you will need to deal with a few issues that many YouTube videos don’t show. One is modifying the gears and motors. That’s because the gears that come with your Power Wheel are designed to run off 12-volts. Once you double the voltage, you will wear the gears out quickly.

Other Battery Modifications

There are other battery modifications as well. A popular one is to replace the Power Wheels battery with a pair of Milwaukee Drill batteries.  Some people use lawn tractor batteries as replacements, while others swap out the motor for a brushless one.

Once you start modifications, it becomes hard to stop. You can upgrade the tires for better traction. Wheelie bars can be added. Some hardy souls will swap out the small motors with a dirt bike motor.

Bottom Line

Putting a car battery into a Power Wheel is not difficult, but it is dangerous and time-consuming. You will have to modify the battery compartment on the vehicle so the larger battery will fit in. That will probably be the most complicated and possibly frustrating part of the process. Otherwise, you’ll need a piece of sheet metal, a few tools, and an hour or two.