Can you use a car battery for an e-bike?

Can you use the same car battery for an e-bike?

   Electric bikes are gaining popularity over traditional bicycles and other automobiles due to their benefits over them. They are environment friendly and do not emit any poisonous gas which is harmful to the environment and pollutes the atmosphere. Parking electric bikes are not painful and can avoid traffic effortlessly. They are much more fun and exciting to be on an electric bike while it is also a cheaper choice.

   It is only cheaper compared to the other automobiles in the market, and owning an electric bike is costly too. The battery of the electric bike with its frames and other electric parts is quite expensive. Replacing or repairing would cost you a lot. In place of an electric bike’s battery, one might wonder if it is possible to replace your old car’s battery. The answer will be, yes and no.

   Before considering switching the car battery for an electric bike, you should have a better understanding of how foreign they are.


Differences between car and electric bike’s battery.

  Batteries convert the electric energy stored into current energy and transmit it to the motor. The size, weight, and voltages vary according to the capacity of the motor and the size of the vehicle. 

   The weight and the size of the car and electric bikes are diverse, and so does their batteries:

Voltages –Car batteries are much larger than the bike’s battery, and it stimulates more power. A car needs power to startup and its battery delivers it. While an electric battery might use up more voltages than a car as it operates and functions on the battery’s energy.

If you wish to replace the electric bike’s battery with the car’s battery, then you should make some changes to the electric bike before.

  • Raw materials

Another main difference is the raw materials used in both batteries. The car’s battery is made up of lead acid and it contains six lead acid cells in a series. As in the name itself you know it will weigh a lot as its density is 11 times the water. These lead acid batteries recharge themselves when the engine runs and uses its voltages.

Though most electric bikes use lithium-ion batteries, few electric bikes utilize lead-acid batteries. As there is no engine, the bike’s battery will not charge the battery, and the rider has to charge it whenever it drains.

The car uses a wet cell lead acid battery to start up its engine. It comes in liquid form without any sealed coverings. It suits the car as it has low chances of crashing and turning upside down, which will leak the battery’s contents out. But electric bike uses sealed lead acid battery which is also in liquid form but has a protective hard plastic cover on it. This is the better choice for electric bikes due to their high chances of crashing and turning upside down. 

  • Size and weight

Lead acid batteries used in cars are large and weigh around 25kg. This is not an issue in an already spacious and engine-running car.

But an electric bike has little to no space for that huge battery and the extra weight will take more power to move. 

The electric bike’s battery does not add too much weight to the bike and does not take up too much space. 

If you plan to replace the car battery, you should consider its size and weight, which would need an extra place on your bike. 

  • Cost

Lead acid batteries are cheap while lithium-ion batteries are expensive. And if you plan to replace the lithium-ion battery with a lead-acid battery, it would cost you little. 

  • Purpose

The purpose of the battery in each vehicle is one of the main things to consider. The car needs the battery to start the engine, while the electric bike needs the battery to power up the bike.

   You would now know how diverse the two batteries are and switching them is not easy as you thought. These differences should be considered and changes are to be made, to avoid the problems you would encounter.


The issues of switching car battery for an electric bike battery.

   Lead acid batteries used in the car are cheap but seize more space and can be dead heavy. While electric bike batteries are small and lightweight they can cost you more. Switching them would benefit the owner. But it can be time-consuming and need many tools.

   Switching batteries should be done with utmost care as it has a high chance of failing and the drawbacks of switching are;

  • Space issues

Electric bike batteries are packed nearly closer together, and they are smaller in size. They use a small slot in the limited space of the electric bike.

 A car battery is large and take-up more space. This is not an issue in a car as it has space. But in an electric bike, it is a major problem as the space is limited. It would take up a huge space and you have to adjust the handlebars and seat to accommodate it.


  • Weight

Even if you adjust your bike to house the car battery in your electric bike, its weight will hinder. The electric bike’s battery is lightweight and does not add a lot of weight to the bike. But the car battery weighs much more than the bike’s battery and it will add up more weight to the bike. Which will cause riding the bike when the battery is dead, more challenging. 


  • Battery cycle

Lead acid batteries supply more power than lithium-ion batteries. But they could not hold the charge longer, like lithium-ion batteries. Their capacity is low and due to this reason, you will not be able to ride too far. 

As the car uses the battery to run the engine, it recharges itself and therefore, car batteries do not need recharging. But the electric bike functions using the energy provided by the battery, and it does not recharge itself. It also drains faster than in a car. So the owner has to charge it when the battery is low.


  • Usage time

Car batteries are valid only for 2 years, by that time the battery would have lost its capacity and you have to replace it. But the bike’s battery if used precisely, can use for five years. 

If you plan to use the already used car battery, remember it won’t last long and soon you would have to replace it. But if you plan on purchasing the low-cost car battery in the local store, it would be fine and you can replace it once its time runs out.


  • Sulfuric acid

Mostly all car batteries are wet cell lead acid batteries. Meaning, that its contents: metallic lead, lead dioxide, lead sulfate, and sulfuric acid, are in liquid form. The container is not sealed and will leak if turned upside down.

Electric bikes are more prone to accidents and they might turn over the battery which would leak all its contents. It would damage anything it comes in contact with, and burn the skin if leaked onto the skin.

It is also dangerous if you crash and the lead wire comes in contact with you, as this will affect your health. 


  • Charger

The car does not need any charger to charge its battery. But an electric bike will need one to charge the battery. And here too an extra cost.


  • Voltage

There are differences in voltage uses. The car uses a battery to start the engine and uses around 13.5 to 14.5 volts. And we use the electric bike’s battery to operate and the overall function of the vehicle, therefore it requires more volts and it comes with around 48 to 52 volts.

If you plan on switching batteries, this has to be adjusted too.


   These are the main issues one might face to switch the battery. And switching batteries can cost you a lot. With the dangers of battery’s liquid leaking and damaging your bike to injuring you. Even though this process is a success, considering the size and weight, it’s still not worth it to modify considering its capacity and the life span of the battery. 


Can you use a car battery for an electric bike?

   It is not simple to answer this question. The process to switch batteries is not as easy as taking out the car battery and fixing it on an electric bike. Its process is time-consuming and takes up too much time. And yes, you can switch the batteries, using many tools and devices. Is it worth it? No, it is not worth it. 

   Even though it is possible to switch the battery, it is not at all worth the time and effort as you will be exhausted carrying your dead battery pedaling back every time it drains out. As the car battery might take up too much space, you would have little to no space for anything else. You have to be extra careful so as not to crash and land in the sulfuric acid the battery might leak. This process is too dangerous and deadly. 

   Even after changing, you can not enjoy long rides due to its short capacity and the life span will be very low. This will frustrate you more. 

   One other advantage in addition to the cost is it generates more power than lithium-ion batteries. Though you can purchase other cheaper batteries that are designed for electric bikes and enjoy a better service than this. 

What alternative what’s do I have to replace my electric bike battery?

   If your electric bike’s battery is dead and you are considering replacing it with your car battery without spending on a new battery, it is our advice not to do so. Though you can use alternatives for your lithium-ion battery.

  1. Sealed lead acid battery 

Sealed lead acid batteries are cheap and safer than the car’s wet cell lead acid battery. It is sealed in hard plastic and as they are designed to suit the electric bike you can purchase this.

Though the lead acid battery designed for electric bikes will weigh a lot and take more space, you can buy one with the same voltage output as your old battery. And it weighs less and takes less than the car battery. 

  1. Other batteries designed for electric bikes

Other batteries designed for electric bike are cheaper on the market. Though this won’t replace lithium-ion batteries, it surely is a better choice than the car battery. Those batteries will weigh less and take up less space while the output of the volts too will be of the same amount, so there will be no need for extra tools and devices.

Other alternative batteries for electric bikes are;

  1. Nickel-Cadmium battery
  2. Nickel-Metal hydride battery
  3. Pedal –

An electric bike is designed like a traditional bicycle but with extra features. In times of a dead battery, you can always pedal your way back using the pedal to work with your effort. Though this might take more effort from your side, it can benefit you in many ways;

  • Help burn your calories.
  • Tightens your muscles.
  • Reduce your weight.
  • Increase your stamina.
  • Increase in cardiovascular fitness.
  • Improved joint mobility.
  • Reduces stress levels.
  • Strengthens bones.
  • Prevention of diseases like diabetes, high blood pressure, heart diseases, obesity, etc.
  • Improve coordination.

These are the advantages of pedaling your electric bike. And we recommend it will improve your overall health while replacing a car battery will risk your health. 

   These are the alternative ways you can use instead of using a car battery in place of a lithium-ion battery. Lithium-ion batteries are expensive and you will wonder if you can save up by trying on other cheap batteries.

  Our advice to you is only to use the same type of battery by the same manufacturer as your old battery. Though it can cost you a lot, you will have the best service from your electric bike. 



   To answer the question, can a car battery replace an electric bike’s battery, is complicated due to the nature of both batteries. Considering the weight, size, packing, purpose, voltage output, battery cycle, etc. it can be extremely arduous to replace. But, it is possible, with many tools and devices you can adjust the car battery to suit the bike and its voltage. This process is dangerous to you and your bike.

   Though, it is not at all worthy of your effort and time. As there are many drawbacks to changing the battery, and even after changing the result is not eyeful. With gadgets and tools with the battery taking up space, you could hardly have space for anything else. If you pedal attaching the dead battery, it will exhaust you, and with the low battery capacity, this would be often if you go on long rides. The worst is if you happen to meet in an accident, the liquids in the battery will leak and harm everything it comes in contact with.

   If you plan to replace the expensive lithium-ion battery with a cheap wet cell lead acid battery, better choices are there. As this replacement will still cost you to purchase tools and devices, you can purchase an alternative battery designed for electric bikes. Eg: sealed lead acid battery, nickel-cadmium battery, nickel-metal hydride battery, etc. When compared to the car’s heavy battery, these batteries are lightweight and you can save more space.

   Or you can always pedal your bike. Pedaling has more health benefits and also you can save up on your money. 

   Try to buy the same battery type as your old one, as it is the best choice. Even if it cost you a lot, you can enjoy the best service your bike has to provide. 


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