E-MTB: Everything you need to know about E-MTB batteries

E-MTB batteries are at least as important as the electric motors themselves. We will explain to you which differences in E-MTB batteries you need to know, how they affect the range of E-MTBs and what speaks in favour of easily removable, integrated batteries.

The battery is at least as important for an E-MTB as the electric motor itself, or the control software. Because the battery provides the energy and determines the range of the E-MTB – i.e. how far you can get with it and for how many meters of altitude the support is sufficient for E-MTB tours. In principle, powerful lithium-ion batteries are used in E-MTBs. However, depending on the manufacturer and model, the energy it carriers comes in different designs, sizes, capacities and shapes. In addition, technical development has made a big leap in E-MTB batteries in recent years: Years ago, a 500 Wh frame battery attached to the outside was the measure of all things for Bosch E-MTBs, but modern E-mountain bikes are now coming up with much larger ones and batteries integrated in the frame (e.g. Bosch Powertube 625). In this battery buying guide we clarify all questions about E-MTB batteries and compare the most important E-MTB motors.

How does the E-MTB battery affect the range of E-mountain bikes?

Basically, the following applies: The higher the battery capacity in watt hours (Wh), the greater the range. In specific terms, this means that you can cover significantly more kilometers with an E-MTB with a large 750 Wh battery than with a 500 Wh battery. A heads-up: You should not rely on the exact kilometers or riding hours that some manufacturers specify for their E-MTBs. Because the range depends not only on the pure battery capacity in watt hours, but also on these factors:

• Weight of the biker: The lighter the rider, the more range. Light pilots therefore have clear advantages in terms of range
• Outside temperature: The range decreases at low temperatures and even more below zero. Tip for winter biking: Start with a warm E-MTB battery.
• Riding style: Consistent riding instead of “stop-and-go” gives you more range. In addition, the cadence should be high enough. Slow cadences below 60 rpm reduce the range.
• Assistance level/mode: Eco mode increases the range. You’re not going as fast as in turbo or boost mode, but you’re going farther and longer.

Nevertheless, when it comes to E-MTB batteries, bigger is not always better. Because increased range gives in to greater weight. A 360 Wh battery, as installed in light E-MTBs, weighs around 1.9 to 2.0 kilograms. A 750 Wh battery like the Bosch Powertube 750 battery weighs 4.3 kilos – more than twice! Below is a recommendation on how big the battery should be for an E-MTB.

Differences in E-MTB batteries: internal or external, permanently installed or removable

With e-mountain bikes, only two battery positions really make sense: With inexpensive E-MTBs, the energy carriers are often attached to the outside of the frame – usually the down tube. One speaks of so-called external frame batteries, which can be easily opened. In almost all modern E-MTBs with a central motor, the batteries are now hidden inside the frame (so-called integrated batteries). This looks nicer, protects the battery and creates space for a bottle cage on the down tube. But just because an E-MTB battery from Bosch, Shimano & Co. is integrated in the frame, doesn’t automatically mean that it can’t be removed. Because there are two options here too: Firstly, the permanently installed batteries in the frame, which cannot be removed or are cumbersome to exchange. And secondly, battery models that can be removed from the frame through an opening. Both have their advantages and disadvantages, which we will briefly discuss.

Advantages and disadvantages of permanently installed batteries

• Less weight: Without a removal opening, the frame can be made lighter (especially important for light E-MTBs)
• Perfectly integrated: You can’t see any opening, the battery fits perfectly into the E-MTB design and is well protected
• Theft protection: The battery cannot be stolen
• Charging: Little flexibility when charging the battery
• Battery replacement: If the battery is malfunctioning, the bike must always be taken to the dealer/manufacturer for replacement

Advantages and disadvantages of removable E-MTB batteries

• Charging: The battery can be easily removed for charging at home or in a café
• Transport: Carrying or transporting the E-MTB (e.g. on the car bike rack) is easier with the battery removed
• Keys or tools required: Depending on the model, you may need a multitool or Allen key to unlock the battery. This also serves as an anti-theft device for the battery
• Exchangeable battery: You can simply use a second battery for long E-MTB tours
• Exchange: If the battery is defective, it can be exchanged easily and quickly
• Battery rattling: If the battery is not securely fixed, it can make annoying rattling noises when used off-road

Removing the E-MTB battery: This is how removal is quick & simple

Integrated batteries often pose a challenge to E-MTB manufacturers: To ensure that the battery does not rattle in the frame while riding, it must be firmly fixed in the battery compartment. At the same time, removing the battery should be as easy and quick as possible. There are basically three options for fixing or removing integrated frame batteries on E-MTBs: with a key, with a multitool or without tools. Removing the battery with a key can be annoying, but it offers an anti-theft device. For sporty e-mountain bikers, on the other hand, it doesn’t matter, so we recommend the simple solution without a lock. Many manufacturers fix the battery against rattling with two bolts. To loosen, you have to unscrew the bolts with an Allen key. Others rely on tool-free click mechanisms to secure or remove the battery (whether with or without a battery cover). In our test reports on emtb-test.com, we indicate how the battery can be removed for each bike.

Removing the E-MTB battery: better sideways or down?

In the case of external frame batteries or partially integrated batteries (the battery sits in an open top tube), removal is easiest from the top. No E-MTB with an integrated battery can match that. Manufacturers have different solutions for removing the integrated batteries from the bike. On Rotwild or Bulls E-MTBs, the battery can be removed from the side of the down tube. On KTM E-MTBs, the battery is removed from the frame triangle using a flap. On Cube E-MTBs, the battery compartment can be opened downwards. With the Specialized Turbo Levo or Canyon Spectral:On, on the other hand, you pull the battery down and out of the frame via a flap on the bottom bracket. There are many ways for this. Tip: If you want to charge the E-MTB battery externally a lot, you should pay particular attention to a smooth-running, safe mechanism without too much fumbling.

What is a range extender on an E-MTB?

A range extender or a dual battery are additional batteries that can be used to quickly and easily increase the range of E-mountain bikes. These second batteries can be added to the bike in addition to the built-in main battery. The range extenders are only available for certain E-MTB motors and models. Using them on other E-mountain bikes is usually not possible. Range extenders have a lower battery capacity than the large main batteries, usually around 150 Wh to 250 Wh. Unlike the main batteries, the range extenders are external batteries that are often shaped like drinking bottles. The additional batteries are either in the bottle holder (e.g. Specialized Turbo Levo or Orbea Rise) or are clicked into the frame triangle of the E-mountain bike in a few simple steps (e.g. Rocky Mountain Overtime Pack). The range extenders supply the engine with additional power via a connecting cable. Since the range extenders are modular E-MTB batteries, they are usually not included when you buy new E-mountain bike. The additional batteries cost 500-800 euros, depending on the manufacturer and model. They also weigh 1.0 to 2.0 kilograms. Especially light E-MTBs with a small main battery can significantly increase the range for long tours. Special E-mountain bikes with a Bosch dual battery system – such as the Simplon Rapcon – or SUV E-MTBs – such as the Flyer Goroc X with a Panasonic motor – use the dual battery option to have more than 1000 Wh on board for extremely long tours.

Bosch, Shimano & Co. – what are the differences in E-MTB batteries?

Although all E-MTB batteries are built the same way, the batteries cannot be combined arbitrarily with every E-MTB motor. E-mountain bikes with Bosch motors have always installed Bosch batteries because Bosch obliges the E-MTB manufacturers to install their batteries. Main competitor Shimano, on the other hand, is open to E-MTB batteries from third-party manufacturers. This gives manufacturers such as Canyon or Orbea the opportunity to install their own batteries tailored to the requirements of their E-MTBs. Nevertheless, Shimano naturally offers external and integrated “standard batteries” for its E-MTB motors such as the EP801, which many manufacturers also use. Like Shimano, Yamaha, Brose and Panasonic also allow bike manufacturers to equip their motors with their own special E-MTB batteries. The advantage of the open battery solution is that retrofit or replacement batteries are usually cheaper. Specialized E-MTBs like the Turbo Levo use special Li-Ion batteries that the Americans develop themselves. The Specialized batteries can therefore only be bought through Specialized and their dealer network. With the Light E-MTB propulsion from Fazua or TQ, there is only one option when it comes to batteries, which is offered by the motor manufacturers themselves. With the Fazua Ride 60, the Fazua Energy battery has 430 Wh. With the TQ HPR 50 drive, the compact, integrated frame battery delivers 360 Wh.

How big should the battery be on my E-MTB?

You are faced with the question of how big the E-MTB battery has to be? For classic E-mountain bikes, the range is currently between 500 and 900 watt hours. You should think carefully about whether you really need a 700 Wh battery or an even larger battery on your E-MTB. Because the long-range batteries also make the E-MTBs 2-3 kilos heavier. If you want to go on really long and altitude-packed Alpine tours, you have to look at 700 Wh and more. Those big – and expensive – batteries make sense for this purpose, too. However, if such extreme tours are the exception and the battery still has a third of its remaining capacity after the tour, you can get by with 500 to 600 Wh. This way you don’t have to carry a lot of additional weight over the trails and the handling is simply better with lighter E-MTBs. In addition, E-MTBs with smaller batteries are also cheaper. With some manufacturers such as Cube or Orbea, you even have the choice with individual models (e.g. Stereo Hybrid, Reaction Hybrid or Orbea Rise) whether you bike with a small or large battery. With light E-MTBs, the battery size ranges from 250 to 430 Wh. The middle ground with 360 Wh batteries is suitable for most E-MTBs in our opinion. An exception is the Orbea Rise with its EP801 motor. Because with the larger 540 Wh battery, it is more of a classic E-mountain bike than a light e-MTB in terms of total weight and range.