E-Bike Batteries: To Go Far, You’ll Need a Good Charge

E-Bike by Martin Haussermann EBIKE battery care

Republished from E-Bike: A Guide to E-Bike Models, Technology & Riding Essentials by Martin Haussermann, with permission of VeloPress. E-Bike is your handy guide to the world of electric bikes.

Without electricity, even the best e-bike motor is useless. That is why an e-biker should always pay attention to the bike’s battery level. Treat your battery well and it will return the favor.

E-bike motors are powered by lithium-ion batteries. This type of battery has been around since the 1970s; today, it’s the first choice in solar-energy storage and electric vehicles, among other cutting-edge applications. These batteries will only continue to improve—and add more fun to your e-bike ride. Regardless of the brand or model of your e-bike, it will help to understand a bit more about the power source of your ride so you can take good care of it and enjoy your ride to the fullest.

The battery compartment has long been the telltale sign that a bike is an e-bike. Whether it is mounted to the rear rack, seat tube, or down tube, the black or gray case is always prominent. That’s changing though. In 2016, Shimano began to hide its battery within the frame—usually flush in a space in the down tube. In the following year, Bosch, then Bafang, quickly followed suit, offering what is referred to as an “in-tube battery.” This design is popular with e-bike owners because it makes for a more elegant frame design and also because it makes an e-bike less recognizable as such, warding off the temptation of theft. You’ll see integrated battery storage in other bikes pictured in these pages, such as the VanMoof and Scott.

Handle with Care

E-bike batteries require remarkably little maintenance if you do a few things to take good care of them. A sudden direct impact, such as being dropped onto a hard surface, is never good for them. Be sure to examine the battery after any direct hit or if you crash or drop the bike, even if it’s not clear whether the battery was hit directly. Take the e-bike to a qualified dealer or mechanic who can discern whether the battery pack is damaged.

Holding a Charge

Batteries will gradually lose their capacity to hold a charge. An average e-biker need not worry, though: High-quality e-bike batteries, depending on the model, are normally expected to last 500 to 1,000 charging cycles. Conservatively estimated, the average distance one can travel with a fully charged battery is 25 miles, so you can expect to have a battery life span of 12,500 to 25,000 miles. Bosch states that after 500 charging cycles, a battery should have 70 percent the capacity it had when brand-new. That battery is still useful, but it will tend to drain faster, and it will need to be charged more frequently. For shorter distances, this gradual drop in storage isn’t a problem, but longer rides could prove more frustrating. If this is the case for you, it’s worth a visit to a qualified shop. A certified mechanic can test the battery and replace it, which can be costly (but worth it): Battery replacement can run $500 to $800. But you’ll gain back the greatest range the battery can offer.

It is possible to find less expensive ways to revive a battery, such as replacing only certain, worn-out subcomponents of a battery with parts found online. However, I advise against taking apart a battery, as correct interaction between the battery pack itself and the electronics of the battery management system cannot be guaranteed.

E-Bike by Martin Haussermann EBIKE battery care steps
The in-tube battery is hidden behind a cover. It is easily removed for charging.

Battery Wear

Battery wear is normal, but there are ways to minimize it. One tip is to charge batteries at room temperature rather than in very cold or hot temperatures, such as in a garage during the cold of winter or the heat of summer. To make it easier to charge batteries at the right temperature, many manufacturers have designed them to be removeable and easy to carry. It is also recommended to avoid letting a battery run completely out of charge; a battery should be fully charged regularly. In fact, there is no harm in charging the battery after every ride, as there is no risk of the infamous memory effect with lithium-ion batteries. (This phenomenon, seen in nickel-based batteries, occurs when a battery is charged before it’s fully empty and cannot reach a full charge again.)

For those who do not have time for long charging times or who regularly travel many miles in one trip, it makes sense to have a second battery. Riese & Müller, for example, offers an integrated two-battery system that increases a motor’s range considerably. The company’s DualBattery Technology places a second, full-size battery within the bike frame, in a position that is designed to minimize any compromise to the bike’s stability. Other options may be putting a second, charged battery in a bike bag or backpack; in that case, be sure to protect the battery from cold as well as physical damage. Consider using a special e-bike bag like those offered by cycling bag specialist Ortlieb.

E-Bike by Martin Haussermann EBIKE battery cold
Neoprene covers protect e-bike batteries from winter’s cold.

Cold-Weather Riding

Riding a bike in the winter does require a little more consideration. When a battery isn’t used frequently in colder temperatures, the ions don’t move as freely, therefore requiring more energy to power the motor. The battery will then lose its charge sooner. Colder temperatures can cut an e-bike’s range in half, which is why e-bikers should use an insulated battery cover in winter conditions. These covers, such as those available from Bosch, are generally made of neoprene and conform to the shape of the battery case. If the bike is going to be stored outdoors or in a cold garage in the winter, it is recommended that the battery be removed and stored indoors. That way, its temperature will be above the minimum advised temperature of 50 degrees Fahrenheit before the next ride. Another way to keep the battery warm, especially in winter, is to use more of its capacity: Instead of always leaving it in a power-saving mode (often called “eco” mode), be sure to sometimes set the motor to higher levels of power. In this way, the battery stays warmer, thereby avoiding a drop in temperature and corresponding drop in performance.

E-Bike by Martin Haussermann EBIKE battery rack
City bike batteries are occasionally built into the rear luggage rack.

Tips on Caring for Your Battery

1) Handling

Take proper care of your battery. When you remove it from your bike, be sure not to drop it or knock it, and when you install it again, make sure it is properly inserted and locked in place. Charge it in dry, room-temperature conditions.

2) Charging Cycles

Batteries with lithium-ion cells can be charged relatively quickly, regardless of their charge status. The integrated battery-management system, which is part of the charging unit, protects the battery from overcharging. Service interruptions during a charging cycle will not harm these batteries either.

3) Charging Unit

Unfortunately, there is not yet a single standard for battery-charger technology; every manufacturer has its own interface and plugs. Jury-rigging a system is not recommended. Batteries should only be charged with the system with which it is sold; otherwise, irreparable damage can occur, or the warranty could be voided.

4) Battery Storage

If a battery is going to be stored over a long period of time, it should not be fully charged. The ideal charge level for longer storage is between approximately 30 and 60 percent, which can be seen on the bike’s display or the diode reading directly on the battery.

5) Winter Use

There is nothing wrong with using an e-bike in winter, but the battery should not be allowed to become very cold. Use specially designed battery and down tube covers to keep the battery a little warmer. For longer breaks and overnight storage, the battery should be removed and kept in a warm room.

E-Bike by Martin Haussermann EBIKE battery bag
Carrying a second battery with you on longer rides offers peace of mind. These types of cargo bags with a separate battery compartment are perfect for transporting your backup battery.

 

For more guidance on your next e-bike purchase, take a look at E-Bike: A Guide to E-Bike Models, Technology & Riding Essentials by Martin Haussermann.