Old model bikes like CT70 often come with a battery. If you take out your old bike from the garage after a long time, the battery is probably dead.
In this situation, a common question arises, will a honda ct70 run without a battery?
Yes, a Honda CT70 will run without a battery because it has magneto ignition. It produces enough power to run a small bike like this one. To run the bike without a battery, you have to do some wiring. However, you may face some problems including a slow start if you run CT70 without a battery.
This fragment of information might not be enough for you to be convinced. Hence, I have prepared a detailed discussion on this matter for your convenience.
Understanding The Power Requirements of Honda CT70
First of all, If you’re not sure whether the battery in your Honda CT70 is in good condition, you can test the battery with a multimeter. If it’s bad and you require a battery for your Honda CT70, you have to choose one according to your bike model.
| Honda CT-70 Series range | Voltage | Dimension | Recommended Battery |
| Honda CT-70 1961-73 | 6 V | 2 3⁄4 in. x 1 7⁄8 in. x 4 3⁄16 in | 6N2A-2C Battery |
| Honda CT-70 1974-79 | 6 V | 2 13⁄16 in. x 2 13⁄16 in. x 4 1⁄8 in | 6N4C-1B Battery |
| Honda CT-70 1980-82 | 6 V | 2 13⁄16 in. x 2 13⁄16 in. x 3 3⁄4 in | 6N4-2A-8(6) Battery |
| Honda CT-70 1991-1994 | 12 V | 4 7⁄16 in. x 2 3⁄4 in x 3 7⁄16 in | CTX4L-BS(FA) Battery |
From the table above, you can see the earlier models of the Honda CT-70 series from 1961 to 1973 required 6V batteries. However, the battery dimensions are different depending on the models.
Honda CT-70 1961-73 requires batteries with dimensions 2 3⁄4 in. x 1 7⁄8 in. x 4 3⁄16 in.
Honda CT-70 1974-79 requires a larger battery with dimensions 2 13⁄16 in. x 2 13⁄16 in. x 4 1⁄8 in. and, Honda CT-70 1980-82 requires batteries with 2 13⁄16 in. x 2 13⁄16 in. x 3 3⁄4 in dimension.
On the other hand, the latest models of Honda CT-70 from 1991-1994 require 12 V or 6-cell batteries with 4 7⁄16 in. x 2 3⁄4 in x 3 7⁄16 in dimension.
You can’t use other batteries like 4-cell batteries here. Because there are significant differences between 4-cell and 6-cell batteries.
That’s the battery requirement for your Honda CT70. When running the Honda CT70, you must meet this power requirement for it to properly function.
So, what about running the bike without a battery? If it’s possible or not, let’s find out in the next section.
Will A Honda Ct70 Run Without A Battery?
Yes, a Honda CT70 will run without a battery. There are two reasons why the vehicle does not need a battery to function.
Reason 1: Magneto Ignition
All models of the Honda CT70 series have a magneto ignition system. This ignition system has its own generator to produce a high voltage of power. When you kick start the bike and the engine rotates, this power is produced.
In this system, there is a capacitor that helps with the power flow and works as a charger. So, the ignition system is fulfilling itself to power the vehicle when running without battery power.
Reason 2: Smaller Than A 150 CC Engine
Magneto ignition is capable enough to provide power for up to 150CC bike engines. But if the Bike engine is bigger than that, or the bike has modern features such as a digital screen, an additional battery is required.
Honda CT70 being an old bike, it doesn’t need too much power to run. All the models of Honda CT70 are between 70 to 72 CC. so, it’s perfectly capable of running only on the magneto ignition system.
Hence, a Honda CT70 doesn’t require a battery to run. But to prepare your bike to run without a battery, you have to adjust some wiring including the stator, rectifier, and regulator. Let’s discuss those next.
How To Run A Honda CT70 Without A Battery?
If there is no battery in your Honda CT70, or the battery just died, you can still make it function. Here’s what you have to do to make it run efficiently.
- Identify the wires coming out of the stator. You will find the stator, a rotating magnetic spike inside the case of the engine. It has two yellow, or sometimes one yellow, and one white wire.
- Take a full wave 12V rectifier and connect those two wires coming out from the stator with it.
- Now, you will notice some wires coming out from the rectifier which is – red, green, yellow, and pink. The red one is the positive output wiring and the green one is the ground wiring.
- Connect the red wire with the capacitor. Then, connect the green one with the ground.
- After that, connect the green wire from the capacitor to the ground too.
- Now, this step is optional. You can attach a regulator with this system just to make sure the capacitor won’t fail. To do this, take a 12V DC regulator. Then connect its red wire to the capacitor.
And that’s it. Now, your Honda CT70 is ready to use without a battery.
Problems of Running The Honda CT70 Without A Battery
Although your Honda CT70 will run without a battery as it has magneto ignition, this ignition has some limitations as well. As a result, you may face some problems.
Here are the common problems you may face while running Honda CT70 without battery.
Problem 1: Slow Start
As I mentioned earlier, the generator of magneto ignition produces power from the rotation of the engine. The engine of the bike initially rotates slower, resulting in less voltage production for the generator.
As a result, the start of your bike will be slow without a battery. However, as the engine speeds up gradually, the generator will produce enough power.
Problem 2: Bulb Filament Can Get Burnt When Revving
When revving, the rpm (revolution per minute) of the engine increases. As a result, the generator produces power more than needed. This extra power flows into the lights and can burn the filament.
Problem 3: Lights Can Be Dimmed When Idling
When you idle the bike, the motor rotates at a very low speed. Hence, the generator can’t produce enough power to fulfill the power requirement of the lights.
As a result, the headlight and tail lights of your bike will be dimmed.
Problem 4: Accessories Won’t Work When Idling Or Running
Sometimes while running the CT70, or while idling, the generator may not be able to produce much power. As a result, the horn or indicator may not get enough power to work if you don’t have a battery.
Verdict
It is possible to start and run your Honda CT70 without a battery. Although you may face some problems, they’re not severe. These problems mostly happen when the bike is idling. But when in acceleration, everything will work just fine.
On the other hand, batteries also come with their own hassle. It’s difficult to maintain the bike battery and the battery may ruin the aesthetics of your classic bike.
So, the decision is yours whether you will use the bike with or without a battery.
FAQs
Is It Ok To Use A Car Battery On A Motorcycle?
No, you can’t use a car battery on a motorcycle. Car batteries are more powerful than the batteries of motorcycles. And this excess power will burn the system of the Motorcycle.
How Do I Know If My Motorcycle Needs A New Battery?
When the battery of your motorcycle is about to die, you will face problems starting the vehicle. Also, the headlight and tail light will be dimmed.
Why Is It Hard To Kick Start A Motorcycle?
When the connection of the ignition system isn’t proper, you may find it hard to kick start your motorcycle. Moreover, an improper fuel/air ratio and a faulty Kickstarter can be the reason behind that too.
Final Words
So, now you know, will a honda ct70 run without a battery or not. If your bike isn’t capable of producing enough power and the horn and lights are often not working, it is better to get a battery. Otherwise, you can carry on without one.
That’s for now. I hope you have a good day and drive safe!
