Charging an electric bike. Table of Contents

Do Electric Bikes Charge Going Downhill? When Braking?

It would make sense that you could charge an electric bike when going downhill or when applying the brakes, but the truth is that the power you’d get back does not make up for the loss in distance and speed.

The vast majority of electric bikes on the market will not charge when going downhill or braking. There are some that do, but it is rare and more of a sales gimmick.

I get asked all the time at the bike shop about whether an ebike will charge while you are riding it and it’s a good question.

The fact is, that even though the technology is available to do this, in practical use it just doesn’t work effectively.

Electric bikes are designed to store the electricity from being plugged in and power the motor to transfer that to you as you are riding.

Why Don’t Electric Bikes Charge When Going Downhill?

It is mainly because the amount of electricity you would be able to generate and return to the battery does not make up for the amount of resistance and energy from you, required to produce it.

In order to to create enough charge to allow the battery to actually gain power, creates a lot of friction and this, in turn, will slow you down. So much so that you would have to pedal pretty hard even when you are going downhill.

So if it takes you pedaling a mile-long downhill (which is a pretty long downhill) to recharge enough energy to go a tenth of a mile further at the end of your ride, you would probably get the same if you just coasted down the hill without peddling and saved your own energy.

Do Electric Bikes Charge When Pedaling?

No, they don’t. Electric bike motors are helping assist you when you are pedaling and therefore using energy not charging it up.

Some stationary bikes at the gym can be operated without being plugged by receiving a charge when you begin to pedal.

This would seem like a great way for you to pedal some power back into your battery on an ebike.

How to properly connect a charger to and ebike battery

The difference is that the stationary bike at the gym is not moving and you only need to supply enough energy to it to power some basic circuitry for the bike to work.

An ebike on the other hand requires far more energy in order to power the motor and actually help assist you in propelling the ebike forward. That’s why they have big heavy batteries.

I used to work for ZAP! Back in 1999, a company that built motor kits for bikes. These motors were rollers that would engage the rear bike tire and spin it forward.

You could lock the roller down onto the tire and pedal to charge the battery, but it felt like riding a stationary bike at the highest setting. It just wasn’t practical.

It would feel like you were peddling with the brakes on and that is the opposite of what riding an ebike is supposed to be like.

3 Levels Of Off Grid E Bike Charging | Amateur To Pro Setup

Ebikes make it feel like you have super-powered legs, not like you are riding through jello.

Can I Charge My Electric Bike by Pedaling Stationary?

No, they don’t, but this would seem like an excellent solution to allow you to regenerate your ebike battery, maybe while out camping or something.

However, I will give you an idea of what would be like if you tried it.

Below is my Bosch data from my average morning commute –

You can see in the right-hand column, 3rd row down is how many watts I am producing per hour. Both rides are about a half-hour long.

Directly to the left of the watts is how many calories I burned. (riding an ebike really burns calories!) Calories are basically a measurement of how much energy I used.

In the top ride, I was producing 154 watts per hour and burned 269 calories in about half an hour, so burning about 538 cal/hr.

In the bottom ride, I produced 125 watts/hr and burned about 416 cal/hr. Every ride will vary a bit with hills and wind.

I averaged about 140 watts/hr for 477 cal/hr. Sorry about all the math, but stick with me

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Keeping in mind this was about an hour-long ride total with a rest break in the middle. So a longer ride would see these numbers begin to fall.

Now, my ebike battery holds 500 watt-hours of juice. In order for me to fully charge my ebike battery, I would have to pedal at the same pace as this ride for 3.5 hours straight, without slowing down, and I’d burn 1,670 calories in the process.

This would all have to be done after riding the ebike long enough to deplete the battery. (about 30 to 50 miles)

This is just not a practical way to charge the bike. I’ll just plug it in.

Some do, but you will notice it. What regenerative braking is, is when you get your ebike up to a certain speed and lightly apply the brakes, the motor will now use your inertia to re-supply the battery with a small amount of charge through the motor.

This can only work on direct-drive hub motors which are simply not as good as geared hub motors and mid-drive ebikes don’t have this feature. Direct drive motors are bigger and heavier than geared hub motors and not used as much.

It makes it so that if you’re on an ebike that has the motor stop assisting you at 20mph and you can exceed 20mph, then you can lightly apply your brake levers and you’ll feel the bike slowing down as energy is returned to your battery.

The problem with this is that you would be having a more efficient ride if the motor just completely disengages and allow you to coast freely or even keep pedaling on your own and maintain your speed.

The only free power for an ebike is from the sun, but that also comes with its limits. Stay tuned for an entire section about Pedaling With Solar Power!

How To Charge Electric Bike Battery At Home

Method 1. Remove The Battery for Charging

Step 1. Turn off your battery. Release the lock to pull it off the bike.

Locate the bike’s power button and switch it off. That will deactivate your battery, making it safer to remove. Here are two possible scenarios:

  • If the bike uses release keys to kick-start the battery locks, insert that key and switch it for better lock disengagement.
  • If tabs or clips are used to secure the battery, disengage it by undoing them. Then slide the batteries off the bike to pull them out completely.

Some regular bikes require you to detach the seat before accessing the battery. Also, do not try to jerk or yank it – since that could hamper the battery connections.

Step 2. Connect your charger adapter and power cord. Plug them into the mains outlets.

Do you see a charging adapter arriving with the bike? Take it and insert its power cord into the adapter’s slot. Once done, plug the cable into nearby electric outlets.

Remember to match the charging cable with the adapter port; only then can you power it effectively. Also, to ensure things are working, seek the green light signal often seen on the adapter.

Step 3. Plug your battery chargers into the charging port.

Put the bike’s battery on a surface as flat as possible. (Cases in point include the ground or your desk).

Next, find its charging port – usually atop or adjacent to the battery’s side. Insert the charger directly into it and wait until the charger light turns on, indicating the charging process has started.

This battery light often produces different colors across brands. Nevertheless, white and red are the most common two.

Step 4. Leave the e-bike’s battery for several hours of charging. Finally, reconnect it with the bicycle.

Bicycles with low electric batteries would demand 6 hours at best until fully charged. Let it sit attached to the charging charger till the indicator lights change colors (ex: orange to green) or turn off.

After that, disconnect the charger and the battery, plugging the latter into your bicycle when you feel ready to bring it onto the street.

One reminder: never let the charger and the battery stay connected once fully charged. Otherwise, the battery charge will overheat and degrade over time. Using the batteries before they are fully charged is also a huge no.

Step 1. Put your bike in a sturdy position and find its charging port.

Lean your electric vehicles against something solid (such as a wall). Another way is to activate a kickstand, balancing it upright and preventing the bike from an easy fall-down.

Next, seek for the battery’s charging port – usually built atop or adjacent to it. The port often resembles multi-pronged outlets on the wall. If you fail to identify it, search the sliding cover at the side and pull it down to expose the port.

For people using outdoor charging stations, ensure the bicycle is tightly secured on a bike rail. That way, it will never fall over.

Step 2. Insert your chargers into the battery’s port directly.

Plug the charger into the power outlet. After doing so, keep an eye on the green lights: when they come on, it means the charger has been connected successfully.

Now take the cord to insert it into the bike’s charging port. Confirm that it’s an all-in plug; otherwise, the cord will slide out!

Most e-bike chargers have white or red indicators during charging, while others do not.

Step 3. Let the bike charge fully before unplugging it.

Wait for about 3 hours (the minimum) before checking the indicator lights again. Have they changed colors or turned off? If not, be patient for another half hour and come back again. After the light changes, unplug the bike and the charger.

Remember not to disconnect the bicycle before the batteries are fully charged. Such moves only shorten the battery age!

Extra Precautions

During charging, never forget to consider all the potential mishaps that might occur. Always charge the bicycle in dry, well-ventilated places far from every flammable material or extreme temperature. Plus, do not leave it unattended!

If you have no choice but to charge indoors, ensure the charger is plugged into dedicated circuits not used by other appliances.

Should I Charge My Bike After Every Single Ride?

Yes. To ensure your e-bike battery level never stoops too low – and hence, put your bike in good condition – remember to plug the battery pack into the charger every time after biking.

Let it charge completely before unplugging, allowing the battery to enjoy maximum capacity. Try to turn that into your habit!

Still, we must say it again: never leave the batteries on the chargers too long after fully charged. As previously mentioned, your batteries might overheat, losing their storage capacity.

How Long Should My Ebike Charge?

The answer depends on the brand, the bike’s makes and hub motors, and the battery capacity before you plug it into the charger. Nevertheless, you can expect to wait from 3.5 to 6 hours for a full recharge.

Cases where the charging period exceeds 6 hours are extremely rare; if that happens to your bike, chances are the charger or the battery size is suffering from internal issues.

Tips of Proper Care/Battery Management to Extend Its Lifespan

Buy A New Battery After About 1000 Single Charges (100% Full)

When exceeding 500 charges, a typical bike battery will begin to drop some power. The time your battery lasts before it needs charging will become shorter over the years. 600 cycles will sacrifice 40% of its capacity.

Hence, battery experts suggest replacing it after approximately 1000 charges (or about 3 years) to ensure the bike’s best functions. Regardless of your charging habit and maintenance, 3 – 5 years are the battery’s prime time.

Store The Battery At least Half-Charge

If you want to store the e-bike longer than several weeks, only do so when the battery is at 50 to 60% of its full charge. Putting the battery away with very few electric currents will be a disaster for its overall health – not to mention, recharging a 100% dead battery only shortens its lifespan startlingly fast.

For winter (or long-time) storage, check it every month and give it a short charge when the capacity is lower than 30%.

Clean The Battery If It Becomes Dirty

Pick a soft cloth to wipe the battery and the electric motor whenever dust and dirt buildups invade them. For stubborn grime and stains, soak the cloth with dish soap for more cleaning power.

Once done, wipe the battery and bike using a dry and clean cloth, leaving no excess moisture on your battery cells. Only then can your bike function well – plus, it also looks much better!

Never Open The Battery

charging, electric, bike, table

There’s no reason to pore them open. Do not examine or repair them – especially lithium batteries!

Most lithium-ion battery options contain lithium powder, an explosive substance that bursts upon contacting oxygen. You may burn down the entire house and hurt everyone. So, let us repeat: DON’T!

If you truly believe something is wrong with the battery, call professionals.

How To Charge eBike Battery Without A Charger?

Electric bikes, or e-bikes, have become increasingly popular in recent years due to their convenience, sustainability, and health benefits. One of the main components of an e-bike is the battery, which powers the electric motor and allows the bike to function. Without a charged battery, your e-bike won’t be able to go very far.

But what do you do if you don’t have access to a charger? Is it even possible to charge an e-bike without a charger?

The answer is yes! There are some. options for charging your e-bike battery without a charger. Some of these options may be more convenient or feasible than others, depending on your specific situation. We have pulled together the best advice and options from leading e-bike manufacturers.

charging, electric, bike, table

It is very important to use the manufacturer’s recommended charger and follow their guidelines for safe charging. If you are experiencing issues with your charger or need assistance, it is best to contact the manufacturer or seek professional help from an authorized eBike dealer. Safety should always be the top priority when dealing with electrical devices.

How Do eBike Batteries Work?

Before we dive into these options, let’s first talk about e-bike batteries and how they work.

E-bike batteries come in a variety of sizes and types, but most e-bikes use lithium-ion batteries. These batteries are rechargeable and have a high energy density, which means that they can store a lot of energy in a small space. They also have a relatively long lifespan, but their performance can degrade over time.

To charge an e-bike battery, you will need a charger that is compatible with your battery. Most e-bike batteries have a standard charging port, such as a USB port or a DC port, that you can use to connect the charger. The charger will then convert AC power (from a wall outlet) into DC power, which is what the battery needs to charge.

Now that you have a basic understanding of e-bike batteries and how they work, let’s take a look at five options for charging your e-bike battery without a charger. Some of these options may be more convenient or feasible than others, depending on your specific situation.

Options For Charging Without A Charger

Power Bank

A power bank is a portable battery pack that you can use to charge your phone, laptop, or other electronic devices. Many power banks have a USB port, which you can use to charge your eBike battery. To do this, you will need a USB-to-battery adapter. You can find these adapters online or at a bike shop. Keep in mind that a power bank may not have enough capacity to fully charge your eBike battery, especially if it is a large battery.

If you don’t have a power bank, you can still charge your battery using a cord and a power source with a USB port. This could be a computer, a wall socket, or any other electric device that has a USB port. Simply connect the cord to the device and to the battery, making sure that the device is compatible and that you are following the manufacturer’s instructions for charging the battery.

Solar Panel

If you have a solar panel, you can use it to charge your eBike battery. To do this, you will need a solar panel with a built-in charge controller and a battery charger that has a solar panel adapter. This can be a good option if you are traveling off the grid or if you have a large solar panel setup at home.

It is important to take precautions when handling solar panels to ensure your safety. Wear protective gear such as gloves, closed shoes, and eye shields to protect yourself from electric shocks and exposed wiring. Depending on the size and weight of the solar panels, it may be necessary to have two people present to adjust their position. This will prevent any accidents or injuries while handling the panels.


To charge an eBike battery using a generator, you will need a battery charger that has a generator adapter. You can then connect the generator to the battery charger using the adapter. Start the generator and turn on the battery charger, following the manufacturer’s instructions for both the generator and the battery charger. The generator will power the battery charger, which will then charge the ebike battery.

Make sure to follow the manufacturer’s instructions and safety precautions when using a generator to charge your eBike battery. It is important to keep the generator in a well-ventilated area and to use it according to the manufacturer’s guidelines to avoid any accidents or injuries.

Charging Station

As e-bikes become increasingly popular, there has been a corresponding rise in production and the development of charging infrastructure for these vehicles. In many areas, it is now possible to find e-bike charging stations both indoors and at various restaurants and bars.

If you find yourself with a low battery while out on a ride, you can locate a nearby charging station and recharge your e-bike battery there. Simply navigate to the station, remove the battery from your e-bike, and place it in a compatible charging port. Keep in mind that some stations may require a fee and availability may vary by location.

Car Charger

If you have a car with a cigarette lighter socket, you can use a car charger to charge your ebike battery. You will need a battery charger that has a car adapter.

It is important to exercise caution when charging your e-bike using a car battery as a power source. The car battery has a higher voltage than the e-bike battery, so it is necessary to regulate the current flow to prevent damage to the e-bike battery. To do this, you can connect light bulbs to the wiring between the car battery and the e-bike battery. The light bulbs will act as a resistor, reducing the flow of current to a safe level.

It is important to keep an eye on the charging process when using this method, as it is possible for the e-bike battery to become overheated or receive too many amps of power, leading to long-term damage.

Final Thoughts

In conclusion, there are some options for charging your eBike battery without a charger. These options include using a power bank, solar panel, generator, and charging station. Consider the feasibility and convenience of each option to determine which one is best for you. Always make sure to follow the manufacturer’s instructions and safety precautions when charging your ebike battery. Remember to look after your eBike battery and charge it in the right way to extend its life.

Now that you know how to charge your eBike battery without a charger, it’s important to protect your investment with the right insurance. Oyster offers comprehensive eBike insurance policies that can protect your ebike against theft, damage, and other unexpected events. Get peace of mind and secure your ebike with Oyster. Act now and get a free quote in less than 2 minutes!

Disclaimer: The information provided in this article is based on general knowledge and research from various sources. These ideas are not endorsed or verified and Oyster takes no responsibility for the accuracy, effectiveness, or safety of these methods. It is always recommended to use the manufacturer’s recommended charger and follow their guidelines for safe charging. If you have any concerns or questions, it is best to consult the manufacturer or seek professional assistance. Use these alternative methods at your own risk, and exercise caution to prevent any damage to your eBike or battery.

Plugging In On-The-Go

Most common and simple method for charging an ebike on-the-go is to bring along a charger and find a common wall outlet to plug-in. While it might be nice to have the largest battery possible for more capacity and less need for on-the-go charging, with more capacity, comes more weight and a higher cost. Batteries already make up a large part of the price of most ebikes and if your typical daily use doesn’t warrant an extra large battery then the cost and extra weight will likely not be worth it.

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  • Bike shops
  • Restaurants
  • Coffee Shops
  • Campgrounds
  • Libraries
  • Picnic pavilions in parks
  • Highway Works Yards
  • Fire Stations

How to charge your lithium-ion ebike battery

When charging on the go, you’ll need to balance two things: how fast you can or should charge your battery and prolonging the life of your battery. Replacing a worn out battery can be expensive so taking care of it by avoiding charging too fast or overcharging it will help prolong the life of a battery pack.

Best practice for prolonging the life of your battery includes keeping your battery cool when in use and when charging and charging slow when you can. However, when you’re on the go or in need of a battery top-up, charging slow may not be very practical. Your ability to charge fast or slow will mainly come down to the type of charger you have with you.

Full Featured Chargers – these types of chargers allow you to change the amps of the charger, increasing or decreasing the charging time. Some of these units even allow changing the voltage, so that different battery types can be charged with the same charger – just be careful to match the voltage setting of the charger with the battery! Two examples of these chargers would be the Cycle Satiator (by Grin Technologies, Amazon link) or the Luna Advanced Chargers. These chargers tend to be more expensive and heavier than fixed rate chargers (below) but do come with more features (as the title suggests).

Fixed Rate Chargers – these come in a variety of Amp ratings but are usually less than 3 Amps. The higher the Amp rating, the faster the charge. These types of chargers don’t offer the flexibility or features of the “full featured” models, but are generally lighter and cheaper, both good qualities when using for an on the go charger.

How long will you need to charge

  • Size of your battery (Ah)
  • Amp rating of your charger
  • How much further do you need to travel
  • What is the terrain/conditions like (flat, hilly, very steep or towing heavy load)

I’ve put together this calculator that will estimate how long you’ll need to charge your battery based on type of charger (amps) and the distance you need to travel (km, working on an equivalent version for miles). Keep in mind this calculation is basic (Time = Ah / A) and does not account for fully topping up the battery, which takes more time at the end of a full charging cycle to balance the cells, but will give you an idea of charging time.

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