Electric bikes allow you to ride further and faster. They’re great if you live in a place with lots of hills and mountains, or you’re just looking for a quicker route to work. They’re great for getting you to work without being a sweaty mess, and they can allow bike riders of different strengths to bike together. They are lots of fun and gaining popularity. Whether you are looking to buy an electric bike or just a battery replacement or if you want to convert your regular bike into an electric one- it can be overwhelming to choose the right battery for your needs. We’ve broken down electric-bike batteries into the different types, what you should be looking for and how you can best take care of them. If you want to know how to choose the right battery for your electric bike, please read on.
Types of Batteries
The most popular (and highest performing) batteries are lithium batteries and include lithium-ion and lithium-polymer batteries. The vast majority of batteries are lithium. You can also find lead-acid and nickel-based batteries, but these are most often found in older and cheaper bike models. These batteries are of much lower quality and are usually much heavier so aren’t usually found in new bikes.
Technology has been continuously improving, and lighter, hardwearing lithium batteries are now definitely your best bet. There are lots of different specifications of lithium batteries with various chemistry components, but there is not much difference between them, just be sure to avoid the lead batteries, unless you are really pushed for price.
We recommend going with the largest battery capacity you can afford, except
- if you have a folding bike that you’re looking to convert to an e-bike, consider choosing a lighter battery, as heavier batteries might have a negative impact on the weight distribution, portability and overall riding experience on a folding bike.
- if you know you’ll only be travelling short distances, it might be worth looking into cheaper batteries with a smaller range.
On the other end of the spectrum, if you are looking for batteries that offer the maximum range against the smallest amount of charging, consider looking at dual-battery systems that use two batteries at once, drawing energy at an even rate from both, keeping you riding all day, even on high power settings.
When it comes to battery capacity there are a couple of terms to be familiar with. There is a difference between Energy and power. Energy is how much power can be delivered per unit time and therefore determines how long your electric bike is going to last. On the other hand, how fast your electric bike can go is dependant on the power (measured in watts) the battery can deliver (and other factors such as weight).
The most important specifications in this context are the following:
- Amp-hour (Ah): This tells you how much energy the battery can store. The higher the Ah rating, the more energy is stored and the longer the electric bike can work. For example, a 10Ah battery pack means that it can supply 10 amps for 1 hour. It also means it can supply 1 amp for 10 hours, and any other variation using the same scale of 10Ah. These are rough guidelines to what you can expect from the battery and exact numbers are virtually never met due to power loss through heat and other aspects of physics.
- Voltage (V): Batteries also tend to have a voltage number along side the Ah rating. This can be used in conjunction with the Ah rating to give you a better idea of how much energy your battery can hold and the power it can deliver. Most electric batteries are either 36V or 48V, but you do get some high-powered batteries at 72V.
- Watt-hours (Wh): a battery that has a 36V rating on it’s 10Ah battery pack means it can be rated at 360 (36×10) Watt-hours (Wh). This gives a more accurate number to volume of the battery pack in the electric bike.
In general, it’s difficult to look at the battery numbers and determine exactly the range you’ll get, as it all depends on the weight of the rider and the bike and other factors such as how fast you’re going, the tire pressure, weather conditions and the terrain you’re on, but when comparing battery capacities, the higher the numbers the better.
Just to give you a rough idea how difficult it is to provide general statements on the range, a 400 Wh battery will give you a range somewhere between 25-70 miles, depending on all the factors mentioned before. There is a nice simulator from KTM that calculates an estimated range based on different choices you can make such as bike and battery model, tires, weather conditions etc. Obviously this is is geared towards their products but you can get a good understanding of how the different elements play together.
There are many possibilities where batteries can be mounted on an electric bike, but mostly they can be found in one of the following positions:
- on the rear rack,
- on the top of the downtube
- behind the seat tube
- integrated into the bike itself.
Bike batteries can normally only be installed in one way, so you’ll have to decide early on where you want to place the battery.
The heavier the battery the more likely it’s going to affect steering, so mounting batteries on the rear rack is really only an option for lighter batteries. This mounting option is also usually found on budget bikes, but don’t discount it, there are some great, affordable models that use reliable e-batteries and are rear-rack mounted.
Battery mounted on rear-rack
Down-tube mounted or integrated batteries definitely look cleaner and sleeker than those mounted on rear-racks and they don’t affect the steering of the bike as the weight is distributed centrally and low.
Battery mounted on down-tube
Integrated battery (inside down-tube)
On folding bikes the batteries are often mounted behind the seat tube.
Battery mounted behind the seat tube
Rear-rack batteries are more suitable for city and touring bikes, while integrated or down-tube mounted batteries are much better for mountain bikes. Integrated batteries stop any chance of knocking or scratching the battery, but those mounted on the down tube are much easier to take off for charging.
An integrated electric bike won’t work well as a non-electric bike but those bikes that have batteries that are externally mounted can easily be used as non-electric bikes, so make sure you think about how you’ll be using your bike in the years to come before committing to the type of battery or e-bike you’re looking to buy. Another important factor to keep in mind when choosing a battery, especially for the externally mounted batteries, is waterproofness, as you would want to ride your bike not only on sunny days.
Different battery manufacturers will have different warranties available on their batteries. Most companies offer warranties according to the time you’ve had the battery or the number of charge cycles that have been used, so be sure to look at what you’re covered for before you buy. Most warranties cover the battery for at least two years.
In terms of quality and reliability, stick to reputable companies such as Bosch, Shimano or Brose, to name a few. It’s hard to determine how long a battery will last because there are so many factors, but you can normally expect them to last between two and four years, though in practice some last a lot longer, especially if you take good care of them!
Making the Batteries Last Longer
When you’re looking to ride an e-bike all day there are a couple of ways to optimise your battery’s performance without compromising on the enjoyment of riding the bike. The following are a couple of ways to make the battery last longer between charging:
- Turn off turbo mode. If you’re looking to be out all day, you won’t be able to speed around on turbo mode for hours and hours. Instead switch between turbo, eco and normal modes depending on what the terrain is like. Turn on the turbo mode for difficult and steep climbs and switch back to eco mode when your legs can handle it.
- Reduce weight. The heavier the bike, the more the battery has to work to pull you up hills. Think of anything you can leave behind or take off the bike, especially if you know you’ll be in turbo mode or riding up steep hills.
- Focus on riding smoothly. Getting to grips with changing gears often will stop the motor having to work overtime to compensate for the gears. This isn’t going to have a huge impact and the more you use your bike the better you’ll get at it, but it is something to keep in mind!
Looking After and Recycling Electric Batteries
Generally speaking most electric batteries can be charged between 500-1000 times, some even more, which should give you plenty of rides. Taking time to properly look after your battery will allow you to prolong its use and get better efficiency from it. Here are some tips for taking care of your battery:
- Store it at the right temperature. Batteries operate best at room temperature, so keep the batteries inside when charging if it’s cold or hot outside. If you’re riding in very cold weather, try to keep the battery indoors for as long as possible before you start biking to prevent the cells from getting too cold. If you find yourself riding a lot in winter, it might be worth looking into getting a battery cover if you find that the battery is draining quickly in cold temperatures.
- Use a good quality charger for the battery and try to avoid chargers that weren’t made for your battery. Try not to overcharge or discharge the battery, taking it off the charger when it becomes fully charged. Charging speed differs obviously from brand to brand but in average it will take approx. 2 hours to charge 50%, with some brands even charging up to 80% in 2 hours.
- Batteries tend to degrade whether they are used or left in storage, so don’t be tempted to stock up on batteries just in case as they’ll be degrading while sitting left unused! If you are going to store batteries make sure they are partially charged (between 30% and 60%) before putting them away as this will stop them from draining completely.
Recycling batteries varies from country to country but they cannot simply be thrown away and must be properly recycled, often at a cost. Often large retailers, such as supermarkets, will accept batteries for you, or your local recycling center might be able to help. If you still can’t find a solution, contact the battery manufacturer or bike shop where you bought the bike to understand how you can recycle the battery.
Wrapping things up
Whether you are looking into buying an electric bike or an electric bike battery only, choosing the right battery will mean that in the long-run you will have something that is more suitable for the type of riding you’re doing. Be clear on what your needs are, decide on the right battery capacity and power for your needs, buy from reputable companies and check the warranties. Remember that any range given is only an estimate, but by taking good care of the battery you’ll enjoy years of electric-powered fun!
We hope that we could help you with relevant information on how to choose the right battery for your electric bike. If you have any questions or doubts please let us know in the comments below!
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