How long does an e-bike battery last?

We have been re-celling batteries since 2017, and the ones from those early years hardly ever come back. Not long ago one came in from a customer who wanted it inspected. Re-celled in 2019, capacity still at 90%.

That is no exception. Most batteries that come back after years are not worn out. The owner wants more: to ride further, to have more assistance on hills, or the bike has become a little harder to pedal because the chain and bearings have worn. People then choose a higher capacity than the original had when they have the battery re-celled.

Want to know what state your battery is in? With a cell replacement or a repair we measure the capacity and you get the test report with it. What that costs is on the page what an e-bike battery costs.

If you are thinking of buying an electric bike, or you already own one, one of the first questions you will ask is: "How long does the battery actually last?" It is a fair question. The battery is the heart of an electric bike and it decides a good deal of how the bike performs and how easy it is to live with. How long an e-bike battery lasts depends on several things: the type of battery, the way you use it, how you look after it and how you store it.

How many years an e-bike battery lasts is worth knowing whether you are about to buy an electric bike or already ride one. On average an e-bike battery lasts about five years, but that varies with use and care. Battery life is measured not only in time but also in charge cycles: the number of times the battery has been fully charged and discharged again.

For most modern lithium-ion batteries that number is between 500 and 1,000 full charge cycles. A 'full charge cycle' does not mean the battery has to be completely empty every time before you charge it. On the contrary, a battery lasts longer if you do not run it all the way down. Charging regularly, even when the battery is only partly empty, extends its life. Extreme temperatures and poor storage shorten the life of a battery considerably. So keep the battery in a dry, cool place and protect it from both severe cold and heat. A battery that is looked after adds years to the life of your electric bike, and to the time you enjoy riding it.

More tips for keeping your battery in good condition are under extending the life of your e-bike battery.

The range of an electric bike, meaning how many kilometres a battery lasts before it needs recharging, matters to every e-bike rider. There is no single figure for it. The distance varies widely and depends on a number of factors.

On average the range of a standard lithium-ion battery is between 30 and 60 kilometres. That depends heavily on the capacity of the battery, the type and model of the bike, the riding conditions, the weight of the rider and even the weather. A battery runs down faster under heavy use, such as climbing hills or riding into a strong headwind. The assistance mode counts as well: a higher assistance level drains the battery sooner.

To avoid disappointment, choose an e-bike with slightly more range than you strictly need. That leaves you some margin when the battery capacity drops a little over time. This matters because every battery loses capacity as it ages, and that goes faster with deep discharges and exposure to extreme temperatures. Keeping to a sound charging routine and storing the battery correctly is what holds the range up over the whole life of the battery.

Example

Picture someone who rides an e-bike to work every working day. The daily ride is 20 km. Kept up five days a week, it soon becomes a fixed part of the routine.

Let us put numbers on that over a period of five years. In one week the rider covers 100 km (20 km a day times 5 working days). That may not seem much from day to day, but over a year it adds up. Assuming about 48 working weeks a year, allowing for holidays and public holidays, this person cycles 4,800 km in a year (100 km a week times 48 weeks).

Over five years the distance is larger still. In that time this rider would have covered 24,000 km (4,800 km a year times 5 years). That is more than halfway round the earth's equator. It says something about the rider's commitment, and about how durable and reliable an electric bike, and above all its battery, has to be to cover a distance like that.

How long an electric bike lasts is a question for current and prospective e-bike owners alike. A well-maintained electric bike lasts between 8 and 12 years on average. That depends on the quality of the bike, on how intensively it is used and on the maintenance it gets. The frame and most mechanical parts, such as the gears and brakes, will easily last a decade or more if they are looked after. The most critical part of an electric bike, and the one replaced most often, is the battery, which usually lasts around 5 years. The motor of an electric bike is generally durable and, treated and maintained correctly, can even outlast the battery.

Regular maintenance and careful use add a good deal to the life of an electric bike. That means cleaning the bike regularly and checking and lubricating the moving parts. Keep it out of extreme weather too. It is also advisable to have the bike serviced once a year by a specialist e-bike mechanic. They can spot and repair problems at an early stage, which prevents bigger ones later.

The theoretical lifespan of an e-bike battery, a 500Wh battery for example, is usually set by the number of charge cycles the battery can go through before its capacity drops significantly. For most modern lithium-ion batteries, the kind widely used in electric bikes, that number is somewhere between 500 and 1,000 full charge cycles. A full charge cycle is a full charge from 0% to 100% followed by a full discharge back to 0%.

In practice, though, a battery is rarely used from 100% down to completely empty. More often it is partly used and then recharged. That means the actual number of usable charge cycles can be higher.

Theory

Suppose a 500Wh battery lasts 800 full charge cycles on average. If a fully charged battery takes you 50 km, then in theory the battery could cover 800 x 50 km = 40,000 km in total before its capacity drops significantly. This calculation is highly theoretical, however. In practice many factors affect the real lifespan of the battery, such as riding style, how often you charge, maintenance, storage conditions and temperature.

Conclusion

The main reason e-bike batteries rarely reach 40,000 km is natural ageing and wear. In practice batteries suffer from moisture and condensation, and from vibration while riding. Another common problem is wear on the contacts, mostly from taking the battery out and putting it back again and again. These factors make the capacity drop faster and shorten the life of the battery, which is why batteries rarely reach the theoretical maximum of 40,000 km.

In practice an e-bike battery lasts about 5 years on average, although that varies widely with the quality of the battery, the type (lithium-ion, for example), charging habits, total use and storage conditions. We have seen a few exceptional cases of riders covering between 15,000 and 20,000 km on a single battery, but that is the exception rather than the rule. Over time a battery can lose much of its usefulness even while it technically still works. Often the capacity has dropped to, say, only half of what it was originally, which cuts the effective range considerably.

Has the capacity of your battery dropped that far? Then we replace the cells in an e-bike battery cell replacement; the casing and the electronics stay yours.

Yes, 6,000 kilometres is a considerable distance for an electric bike. By comparison, the average e-bike owner rides less than 1,500 kilometres a year. As for lifespan, the battery of an electric bike usually lasts up to about 15,000 kilometres; now and then we see one reach 20,000. That can vary with how the bike is used and maintained. The range, meaning the distance you can cover on a full battery, varies with the battery capacity.

Say you have an electric bike with a 400 watt-hour battery and your energy consumption is 10 watt-hours per kilometre. You work out the range by dividing the capacity of your battery (400 watt-hours) by your consumption (10 watt-hours per kilometre). That gives: 400 / 10 = 40. So with a 400 watt-hour battery and a consumption of 10 watt-hours per kilometre, you can cover about 40 kilometres on a full battery.

It is good to know that you have a say in how long the battery of your electric bike lasts. One point to remember: a battery is not only 'finished' once it has stopped working altogether. It is really time to replace your battery when it no longer holds enough charge for your daily routes, such as from home to work and back. If you notice that your battery no longer covers that distance, the moment has come to think about buying a new one.

Not sure whether you have reached that point? The page on when to replace your e-bike battery sets out the signs.

Electric bikes have improved considerably in quality in recent years. Older models are technically outdated and suffer mainly from a limited range. An electric bike from the early 2010s with more than 20,000 kilometres on the clock usually has little residual value in its current state. That value can rise considerably, however, if the bike is fitted with a new, re-celled or refurbished battery, especially one that comes with a warranty.