Time to ditch the battery key!

Emtbs have changed so much since they started appearing in any numbers. Five years ago, many emtb’s had wide plus-tyres and a frame mounted external battery with a key. The plus-tyres are gone, thankfully!

The external batteries have pretty much disappeared too. But, the battery key is still around. Yeah, all of this can still be found on Alibaba. But I’m talking about proper hard-charging trail and enduro bikes by big reputable brands. Many still use a key to secure and remove the battery.

The 2017 Haibike sDuro allmtn. Back then lots of emtbs had plus-tyres and external batteries.

The 2017 Haibike sDuro allmtn. Back then lots of emtbs had plus-tyres and external batteries.

But it’s nice to have a key, right?​

Sure, with a bit of imagination, I can think of some scenarios where the key is an advantage. Locking the battery could be an advantage on rental bikes. But, for the most part, I think the key is a disadvantage on an emtb.

I believe the key has caused more problems than it has solved. In addition to unlocking things, keys are small, easy to lose and often hard to find.

Most likely, you aren't lucky enough to find your key in the couch.

Most likely, you aren't lucky enough to find your key in the couch.

Complex, heavy and costly​

Another problem is batteries that don't attach to the frame properly, causing knocking or rattling, or even batteries falling out in some cases.

Battery mounts must be calibrated when the shop is getting the bike ready for delivery. And the mounts can come out of alignment with time. I’ve adjusted battery mounts on a few bikes with both internal and external batteries. Sure, the key isn’t directly to be blamed for this.

But pretty much all bikes with a key use this kind of battery mount. These mounts add complexity, and they’re surprisingly heavy. Mounts and lock cylinder can add up to 500-600 grams.

And then there’s the additional frame weight; manufacturers often need to beef up the frames to account for battery locking hardware, or reinforced areas on frames where a big battery hole is made, especially on frames where a battery is side loaded (Trek Rail) or loaded underneath the down tube (eg, Orbea Wild).

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Adjusting the upper battery mount when setting up a 2019 Canyon Spectral:On

No key, less weight​

Currently, it seems there are as many lightweight emtbs being launched as heavier, full fat emtbs. A lightweight emtb will of course have to be reasonably lightweight. Therefore, these bikes mostly come without a battery key. And most of them come with a non-removable battery.

The 2023 Pivot Shuttle SL, a lightweight emtb with an internally fixed battery.

The 2023 Pivot Shuttle SL, a lightweight emtb with an internally fixed battery.

Fixed battery​

Fixing the battery inside the frame is the easy solution. Batteries can be installed using simple and lightweight mounts. So, there is no need for a huge hole in the down tube for battery removal. And there is no need for extra frame reinforcement in this area. This can double the weight savings.

Production is simplified and cost is reduced. This isn’t a new solution of course. Already in 2018 I reviewed the Focus Jam2 with an internally fixed battery.

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Focus Jam2 with an internally fixed battery and a range extender on top of the down tube.

But having an easily detachable battery is important to some. Not everyone has the option take their bike indoors. Those who live in colder climates need to bring the battery indoors for charging during the winter. It's best to start the ride with a room tempered battery, to optimize range. Having a detachable battery can also be important when transporting a bike on a rack. A 20 kg weight limit is common for bike racks.

Rob did a survey on his Instagram, where he asked what people thought of detachable batteries. I was a bit surprised about how many people prefer an easily detachable battery.

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Your dream bike only comes with a fixed battery. Would you still buy it?

Batteries that can be inserted into the bottom of the frame​

Specialized made a good solution for a removable battery on their 2019 Levo. They made a small opening at the bottom of the frame. Here the battery is inserted and attached with a hex bolt. Most of us carry hex keys in a tool box or even on the bike, making it far less likely to be stuck somewhere without a key that fits!

Also, a single removable bolt doesn’t require the big battery mounts and it requires less frame reinforcement.

The battery is located as low in the frame as possible, which improves weight distribution. This requires the front of motor to be tilted upwards, to avoid blocking the battery opening. Not everybody likes the looks though. The frame is quite bulky in the crank area.

Also, it’s more challenging making a waterproof solution for connecting the power cable. Specialized improved their battery power plug for 2022.

Rob removes the battery from a 2022 Canyon Spectral:ON CFR.

Rob removes the battery from a 2022 Canyon Spectral:ON CFR.

Other manufacturers have since used the same method, but I think it’s surprisingly few. Removing the battery by sliding it from the bottom of the bike is more time consuming, and slightly more hassle. But I don’t think that’s of much importance to most people, not on an emtb.

Trek has a similar slide-in solution on the new Fuel EXe, but they decided to attach the battery using two smaller allen bolts.

The lower bolt holds both the battery cover and the battery. The upper bolt only holds the battery. Removing the battery takes some time. But the battery is removable, and that’s the most important thing. This design doesn’t add much weight compared to a non-removable battery.

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The Trek Fuel EXe battery is removable.

The old implementation without a key​

Some brands chose to keep the battery mounts but ditch the key. This doesn’t necessarily reduce bike weight. Still, I think it’s an improvement.

Late 2019, Shimano introduced a new internal 504Wh battery. The traditional lock cylinder and key was gone. Now you only need a 4mm allen key to remove the battery. Several brands decided to include the tool in the bike. Merida fitted the tool in the rear axle. I found it a bit difficult operating the unlocking mechanism, it wasn’t easy seeing where the bolt head was.

Still, I like it, it’s an improvement. There are other solutions that relies on an allen key too. BESV simply swapped the locking cylinder for one that is operated with an allen key.

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BESV simply installed a lock cylinder that opens with an allen key. Easy and convenient

The Bosch 750Wh battery will be on lots of bikes going forward. This is one long battery, so it’s difficult making room for it in the frame. The battery mounts have to go, there isn’t room for them. Some chose to fix the battery, making it non detachable.

Rotwild keeps the regular battery mounts, but the lock cylinder is replaced with a button. Easy and practical!

Rotwild keeps the regular battery mounts, but the lock cylinder is replaced with a button. Easy and practical!

Moustache use a screw on the top side of the down tube. The screw is finger-operated, and the battery tilts out of the down tube in the regular fashion. The frame needs reinforcement around the big opening in the downtube but avoiding the big battery mounts saves weight.

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Moustache has a clever way of making the huge Bosch Powertube 750 battery detachable.
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Not completely gone​

I believe emtbs with a key will be made for years to come. But my claim is most new bikes won't have a battery key. This was an easy solution that we accepted initially.

Now the time has come for more brands to invent more clever ways of implementing the battery. And I think it's time to say goodbye to the battery key. You won't be missed!
About author
knut7
Started mountainbiking in the 90s. Moved to emtbs in 2014 and have been reviewing them since 2016. Contact me here https://emtb.no/contact/

Comments

I'm that one guy. I ride a Rail 9.8XT, and I think an easily removable battery is an absolute must, be that with a key, or a simple special easy to use tool (that's not a key, honestly). Here's why....

Charging indoors has already been mentioned, as has starting off a ride with a room temperature battery. But my double glazed shed in the south of the UK has a metal roof, it regularly hits 40 deg C on a summer's day, bad for battery degradation. I keep my battery indoors where it's a consistent temp, summer or winter.

If someone breaks into my shed, it's one less thing they'll be able to steal. And it's worth almost £900!

Like a lot of people, I make pub/cake stops 😁 it makes a quick charge up a LOT easier if you can whip the battery out in 5 seconds.

Storage and transport. My bikes hang on ceiling hooks vertically against a wall. E-bikes are heavy enough to lift up without the battery fitted. This goes hand in hand with travelling. Loading bikes into and out of places is easier, and the battery's generally sit somewhere out of the way.

If you have a problem on the trail and need to reset the bike, this has happened to me once. Key/battery out/battery back in/get riding again. No buggering about for ten minutes with tools you don't carry in the camelback you left at home.

I understand people have issues but honestly, I've had no problems at all apart from a slight rattle which was fixed by careful alignment. How are people loosing keys? I generally ride with a phone and a form of payment, taking a key isn't really a hardship, and half the time it's in a pocket with a car key?
 
I need the option of an easily removable battery so I can do very long rides with more than Eco mode.

Do we have any numbers on how much weight a key locking mechanism adds over a comparable non-keyed battery mount?
 
the key/mount hardware on my ebike are very annoying, the alignment is way to finicky to reset when it comes out of alignment. but for me an easily swappable battery is a necessity. on ebike trips i run through 2 batteries each day riding all turbo mode. i think the mounting hardware needs to be rethought more than anything. whether there is a key or not, i guess i dont really care
 
Not meaning to cause an argument, but the questions or statement rather in the first part is a bit off.
1. is there a strength or stiffness issue just because frames have removable batteries ?.

Certainly this isnt an issue or has even been brought up. But apparently now these are questions with predetermined answers. Overall the questions appear less like questions and more like statements.
 
I too consider a detachable battey to be an absolute requirement and will echo reasons previously stated. I remove the battery for transport on my 1.25” hitch rack. In inclement weather I bring the batteries indoors to charge. In fact, purchased two Treks, a Powerfly and a Rail, because their batteries are directly interchangeable and this gives me an additional battery to bring with me for extra long tours or days at the bike park. I wouldn’t look twice at a bike that did not have a detachable battery.
 
I have a Cube 750Wh with this lock and key:


It can't be too difficult to modify the lock, so it accepts a 5 or 6mm Allen key.
 
I agree that a key is unnecessary. The list of things I need to take on a bike ride is longer with the Emtb as they include the Kiox display and the Key. Both of which can ruin a weekend. I did a ride with a friend a while ago where we took 2 batteries. He forgot his key!
I remove the battery for Transport when carrying multiple eMtb's on my Towball rack, for storage and often for charging.
For the last 4 years I have done 7 Day TransAlp tours where you need to charge every lunch break, and wherever you overnight. Often requiring the battery removal.
With the external batteries I see that a key was good, so people couldn't quickly grab an expensive battery and be gone. But with the internal hidden batteries it is a bit more difficult, so I think the key is unnecessary.
Would be nice if it was an option, like adding a padlock.
 
For me, a removable battery is a must and the easier the procedure the better. I'm not scared that the battery would be stolen out of the bike, hence the thieve would much more likely be taking the whole bike instead of just the battery. Both would be covered by my insurance, so it might be even better when the whole bike is gone, at least financially.

Then some other reasons pop up in my mind, as servicing, swapping the battery, transport etc.

#killthekey
 
Storage and transport. My bikes hang on ceiling hooks vertically against a wall. E-bikes are heavy enough to lift up without the battery fitted. This goes hand in hand with travelling. Loading bikes into and out of places is easier, and the battery's generally sit somewhere out of the way.

Have you looked at a Floaterhoist? Pull the bike up to the ceiling with ropes rather than lifting. I've had 2 for about 7 or 8 years now - great piece of kit!
 
I'm more likely to lose a Hex key than a ordinary key.
I have no problem using a key.
The hardest part in removing the battery is pushing the button and sliding it to remove the battery cover due to it having to be water proof.
I don't need to remove the battery to charge it, but it makes lifting the bike a bit easier.

I would bet that manufacturers would love for batteries to be fixed and unreplaceable, so you have to buy a new bike when the battery is shagged.
Maybe they could even make the bike go slower as the battery gets more knacked so it lasts longer..... (Apple have experience with this)
 
I 100% need a removable battery as often it'd be stuck in the car boot in incredibly high temperatures. It also helps for people who want to charge a battery in a hotel room or apartment block without carrying the whole 29KG bike inside! As well as those who swap out batteries to double their rides or to replace them.
 
Have you looked at a Floaterhoist? Pull the bike up to the ceiling with ropes rather than lifting. I've had 2 for about 7 or 8 years now - great piece of kit!
They're a nifty idea, but I've got 6 bikes hung off the roof joists in my workshop by the front wheel. That's £600 worth of hoist Vs £25 of hooks from Screwfix 😁
 
I had the Orbea wild with the key,Abus lock was brutal,Would stop working and could take ages to get the battery out!!
Keys were made of cheese and one snapped in the lock and had a ballache to get it out,On another occasion my battery fell out the frame luckily was on a grass field😳
The alignment of the key hole never married up to the hole in the frame either
Now on a Whyte and it uses two bolts to hold the battery terminal in place plus one goes in through the outer plastic cover
A big more Faff but proper secure
I like to have battery out to keep indoors as it keeps the battery health better especially storing outside in UK winters
 
I had the Orbea wild with the key,Abus lock was brutal,Would stop working and could take ages to get the battery out!!
Hah, yeah, I had forgotten about that. Cable routing wasn't that great, so cables would come into conflict with the battery. If you managed to get it in, it could be difficult getting it out again. And I never got the battery mount to align properly with the key hole while simultaneously holding the battery properly.
 
I'm that one guy. I ride a Rail 9.8XT, and I think an easily removable battery is an absolute must, be that with a key, or a simple special easy to use tool (that's not a key, honestly). Here's why....

Charging indoors has already been mentioned, as has starting off a ride with a room temperature battery. But my double glazed shed in the south of the UK has a metal roof, it regularly hits 40 deg C on a summer's day, bad for battery degradation. I keep my battery indoors where it's a consistent temp, summer or winter.

If someone breaks into my shed, it's one less thing they'll be able to steal. And it's worth almost £900!

Like a lot of people, I make pub/cake stops 😁 it makes a quick charge up a LOT easier if you can whip the battery out in 5 seconds.

Storage and transport. My bikes hang on ceiling hooks vertically against a wall. E-bikes are heavy enough to lift up without the battery fitted. This goes hand in hand with travelling. Loading bikes into and out of places is easier, and the battery's generally sit somewhere out of the way.

If you have a problem on the trail and need to reset the bike, this has happened to me once. Key/battery out/battery back in/get riding again. No buggering about for ten minutes with tools you don't carry in the camelback you left at home.

I understand people have issues but honestly, I've had no problems at all apart from a slight rattle which was fixed by careful alignment. How are people loosing keys? I generally ride with a phone and a form of payment, taking a key isn't really a hardship, and half the time it's in a pocket with a car key?
Agree w you 100%. way easier to remove battery for storage/charging in home & lifting bike when much lighter for transporting
 
I keep the key with the flat repair kit and the other tools I’m going to have anyway. And as far as rattling, that is very easily solved with a little piece of stick on foam to create some pressure. I don’t care at all either way.

But I definitely hate the huge bolt used on my wife’s Fantic. It has an excessive amount of thread, and just takes more effort than it should.
 
Just a thought, but should you be unlucky enough to lose the key, whether it is a proper key or an Allen key, which one is the more likely to be easily replaced, or borrowed from another person? Obviously it is the latter type, and although I know this means that an Allen key-toting thief would probably have a better chance of nicking a battery, in the real world they’re far more likely to just pinch the whole bike, surely?

We’re fortunate enough here to have a small room out in the garage/store which is insulated and can be readily kept at a warm temperature with a frost stat heater, in which to store the various Lithium battery kit, which IMO is too risky to have inside the home: in the event of a battery fire (however unlikely) you don’t want to have the Li batteries go up inside your home - if you can possibly avoid it.

 
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