Introduction: Double Ride-On Speed


  • Convert 2 Ride-On kid cars from 6V to 12V safely to double the speed
  • Learn something about batteries

This instructable covers how to convert 2 (ride-ons) from 6V to 12V by the easiest means possible. There is a lot of information on the web about this and even a course on udemy here, but I wanted to write up this instructable since I was surprised on how spread out the information was that I needed.

My initial plan was to take one of the 6V batteries from one car and wire it in series (12V total). Then replace the missing battery in the donner car with a 12V SLA battery.

After multiple mistakes, I determined the simplest solution was to just swap both cars' 6V batteries with 12V batteries and use a battery maintainer to charge. (Mistakes discussed in last section)

I took on this project, because our family was super kind and bought our kids these cars. However, the cars would move so slowly (2.5 mph) that we could not even use it when walking the dog. It would barely work up small hills and almost certainly did not work on grass. My kids which were super pumped up with their gifts quickly become disinterested, because our 2-year-old could out walk it.

6V to 12V will theoretically double the speed (2.5 mph to 5 mph)

These cars are rated for 6V, so increasing the voltage increases the risk of damaging/burning the wires and components (motors, LEDs, etc). This initially deterred me from making any changes. Watching youtube videos and reading posts online relieved some of my worry to push through.

The rule of thumb is 6V to 12V is okay. 6V to 18V is probably going to burn out something. If you have a 12V car, you may be okay to increase to 18V.

Doing this will void the warranty


Mighty Max Battery 12V 7AH Sealed Lead Acid [x2] ($17.99) - Amazon

Solderless Terminal Kit, 305 Pc. ($9.99) - Harbor Freight

Schumacher SC1355 1.5A 6/12V Fully Automatic Battery Maintainer ($37.26) - Amazon

Schumacher WM-12 12 Cable Connector for Battery Charger / Maintainer ($5.79) - Amazon

Step 1: Find and Purchase Your New SLA Battery

SLA – Sealed Lead Acid


This is important for these cars, because the seal prevents the battery acid from hurting kids if the battery were to be damaged.

Mighty Max Battery 12V 7AH Sealed Lead Acid ($17.99)

I found one of the cheapest 12V SLA batteries I could find. I personally didn’t care about AH, because the driving sessions are usually less then 30 minutes anyway.

*This will require a different battery charger which I discuss later.

Step 2: Perform the Battery Swap

Spider-Man Car: (manual)

TURN OFF THE CAR. Remove the 6V battery. Unscrew the bracket and pull of the terminals. The terminals were glued in place, but it wasn’t too hard to separate.

Place the 12V batter in the slot. The 12V batter will actually fit nicely.

Replace the bracket.

That’s it!

Princess Car: (manual)

This one was slightly more involved since I wanted to “scrap” the fuse holder attached to the 6V battery.

TURN OFF THE CAR. Disconnect the 6V battery. Unscrew the fuse protector and fuse holder. Cut at least one of blue bands encasing the batter.

Now disconnect the terminal from the batter and fuse holder. Remove the fuse holder from the blue casing. Save the spare 15 amp fuses too.

Due to previous mistakes, I had the white connector (which connects to the orange connector) already cut. I simply used Solderless Terminal Kit From harbor freight to connect the fuse in between the red terminal and the connector.

Ill discuss fuses shortly.

Place the 12V batter in the slot. The 12V batter will actually fit nicely.

Replace the bracket.

Step 3: Test

Turn the cars on and make sure it works. It will move quick.

Step 4: Charging

The original charges WILL NOT WORK. They are rated for 6Vs. A 12V charger is now required.

The absolute best solution is a battery maintainer. It is reasonably cheap, can auto detect and charge both 6V and 12V batteries, and best of all you can leave it connected. No more setting timers and making sure you unplug the charge after 18 hours. It extends the batteries expected usage too.

I found 12V Automatic / Float charges as cheap as $8.99, but I decided to go with the brand I kept seeing in reference to power wheels enhancements: Schumacher

Schumacher SC1355 1.5A 6/12V Fully Automatic Battery Maintainer ($37.26) - Amazon

Since I had two cars, I bought an extra Cable connecter to swap charging cars easier:

Schumacher WM-12 12 Cable Connector for Battery Charger / Maintainer ($5.79) - Amazon

Step 5: A Little About Fuses

This initially was the most confusing part for me at first, because many of the sources I found online would just simply say to swap out the 15A fuse with a 40A fuse. I couldn’t understand how that could just work.

That being said, do yourself a favor and watch this video:

Basically, fuses are used to protect both wires and components within the circuit. If there is a pulse/surge of too many amps then the fuse burns out instead of your motor for instance. This is the reason why the fuse is as close to the positive (red) terminal as possible.

On these cars, you can literally swap how the positive and negative terminals connected to the battery and it will flip forward and reverse. However, this circuit now has the fuse last so if there was a surge, odds are the motor will burn out before the fuse.

As far as swapping a 15A fuse with a higher fuse, even a 20A or 25A fuse will increase the risk of permanently damaging wires/components. I have seen several people (sources online) swap 15A fuses with 40A fuses and be totally fine. I guessing this is in part due to luck and also safety factors built into the components themselves.

I personally have swapped out the 15A fuse with a 25A fuse and have been fine (SO FAR). I attempted to stick with the 15A fuse, but it burned out 3 times while riding on the grass. I went with a 25A instead of 20A fuse, simply because that is what I had on hand.

Note: The Spider-Man car already has a self-resetting fuse in line with the original battery terminal.

Step 6: Results

Although it is a one seater, two of my kids can squeeze in at the same time into either car (total of ~ 60 lbs)

*Both cars are rated for 65 lbs MAX

It now works on grass (mostly) and up hill. The fuses trip more often on grass, especially the Spider-Man cars self-resetting fuse. Usually, only have to wait <10 seconds.

Both cars are fast enough where a light jog is needed to keep up.

Lights on the hood are still working.

Even if these cars do not last much longer for any reason, it was worth this change. The kids did not care about driving it and now they love it. The costs of the upgrades have already paid for themselves.

Step 7: Mistakes / Lessons Learned

My initial plan was to take one of the 6V batteries from one car and wire it in series (12V total). Then replace the missing battery in the donner car with a 12V SLA battery.

I thought I would save money on a battery with this approach.

Mistake 1: Accidently wired the two 6V batteries in parallel instead of series.

This is actually fine, but this only increases the usage time (AH).

My objective was to increase speed not run time.

Mistake 2: The two 6V batteries did not match perfectly

This could shorten the life span

Mistake 3: I thought the same charger would work

Refer to my analogy above.

They have to be charged individually which adds to the wait time between sessions.

Mistake 4: Two 6V batteries don’t fit well inside

I probably could have gotten around this if I had the identical battery since there are 2 slots, but they would have required more money.

Mistake 5: Used Connectors to try and swap out quickly

There isn’t really a problem here other than I did not do a good job making it and had a short somewhere which caused me unnecessary headaches.

Batteries with different voltages can be connected in series and will sum the voltages together.

Example of wiring a 12V battery and a 6V battery in series would result in 18V. (12V + 6V = 18V) This is why there are online posts about converting a 12V power wheels to a 18V. With 12V ride-on’s, the wiring and components are designed to handle that increase. Some can even handle going up to 24V.

Now wiring batteries together in series with different current rating (Amps) is also possible, but the effective combination will be the lowest of the 2 ratings.


  • Princess Car: 6V / 5.0 AH battery
  • Spider-Man Car: 6V / 7.0 AH battery

The lowest AmpHour rating is 5.0 AH so the combination result is 5.0 AH.

One of my sources:

AMP Hour is a unit of measure for a battery's electrical storage capacity. The standard rating is an amp rating taken for 20 Hours.

Voltage represents the pressure of electricity. Some applications require more "pressure," meaning higher voltage.

Helpful Link

Step 8: Sources

These were the most influential sources I used: (Part 1) (Part 2) (How To Make Your Power Wheels Faster! Converting 6V to 12V!)

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