Can You Fix Your Electric Bike Battery. Bosch ebike battery repair

Common E-bike Battery Problems and How to Fix Them

There’s nothing worse than having to spend hundreds or thousands on an eBike only to have problems with its battery. Don’t get me wrong; e-bike batteries are built to last. but they’re still prone to failure if they aren’t adequately taken care of during their lifetime.

What happens if your battery fails?

Well, in this article, I’ve covered some most common eBike battery problems and how to fix them. So, if you’d like to know more. keep scrolling!

Ebike Battery Problems

When it comes to eBike troubleshooting, there are a couple of things that might be causing your battery problems, including:

  • eBike battery pack swelling
  • eBike battery not charging
  • eBike battery not running for very long
  • eBike battery pack not holding a charge
  • eBike not turning on
  • eBike not speeding up

Don’t worry, though. I’ll walk you through each one here!

eBike Battery Pack Swelling

If your eBike battery pack is swelling up, well, you likely have a pretty serious problem with one. or more. of the lithium-ion cells.

Some electric bike models use flat pack cells. and these are known to swell if they suffer some damage. On the other hand, the 18650 lithium-ion cells are far more resistant to swelling and, in turn, more reliable.

If you notice that your eBike’s battery pack has a bulge in it, be sure you turn off the power and carefully remove the battery from your eBike. It’s a good idea to recycle the battery; most cities have a place where you can do this.

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Now, some eBike battery packs are positioned inside the bike’s frame. That makes it somewhat harder to notice if you have a swollen battery pack.

The only way to check if the battery is swollen is to drop the lower plate and take out the battery pack. Note that you’ll have to disconnect some cables before you do this.

eBike Battery Not Charging

If your battery isn’t charging, start by checking the following:

  • Is the power turned on at the outlet?
  • Is the charger working and outputting over 36 Volts?
  • Is the battery hot?
  • Is the battery charger port full of dirt?
  • Has the battery been left discharged for several months?
  • Has the fuse blown in either the eBike battery pack or the charger?
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eBike Battery Not Running For Very Long

Lithium-ion batteries generally have a life of 700 charge cycles. They usually tend to lose full charge capacity over this mark.

That is entirely normal. and will, unfortunately, only get worse as time goes on.

Still, if you’re charging your bike every few days, you should be able to get many years out of your electric bike before you begin to notice the capacity of your battery is starting to degrade.

If you notice your eBike battery isn’t running as long as it used to, check the following:

  • Is the battery pack being charged to 100%?
  • Do you have a dragging of a disc brake?
  • Is the terrain uphill?
  • Are you assisting your battery by peddling?
  • Are your eBike’s wheel bearings freely spinning?
  • Do you have a short circuit in the battery, wiring, or motor?

Any of the scenarios mentioned above could lead to your battery discharging rather quickly.

eBike Battery Pack Not Holding A Charge

Lithium-ion batteries are good at holding a charge. However, like any other type of battery, they will slowly discharge over time.

If your eBike hasn’t been charged for a more extended period, it would be a good idea to give it a top-up. and see how it goes.

If you notice that you’re charging your battery, but it still discharges quickly without being used, you might have a short circuit somewhere or a faulty battery at your hands.

Here’s a quick test that can detect the problem:

Remove the battery pack from your eBike and charge it up on a bench. Once it’s fully charged, test the battery by leaving it off the bike.

If it holds a charge, the issue will be your electric bike. most likely a short circuit in the bike’s wiring or the motor. However, if it doesn’t hold the charge, your lithium-ion cell is faulty.

How Do I Know If My Bike’s Battery Is Charged?

Your battery charger will probably feature a LED light indicator that changes states depending on the bike’s battery level. It’ll go from red to green when the battery is fully charged in most cases.

However, in some chargers, the LED light will turn off completely when the battery is charged.

Either way, the point remains the same. you’ll have a way to track the progress while charging the battery.

Remember not to leave the battery pack on the charger longer than 24 hours, though.

Lithium-ion batteries don’t prefer being left on the charger. In the short term, this won’t hurt. but after a while, the battery’s capacity will go down.

You’ll also have an indicator of the battery’s current level on the battery pack itself or the speed controller. Some will use a 0-100% range, while others have a series of LED lights, depending on the model.

eBike Not Turning On

Let’s start with the obvious solution:

If your e-bike isn’t turning on, be sure to check if the main switch is in the “On” position.

Next, check the fuse for the battery pack. This fuse is usually located on the side and could blow up because of short circuits, vibrations, over-current, or old age.

If the fuse is in good condition and the battery pack is fully charged, check if the speed controller is in good condition, as well. The speed controller is the component that sends signals to turn on the battery pack.

These speed controllers could malfunction if damaged. either by dropping your bike or allowing water to get into them.

Hold the bike’s “On” button for about 10 seconds to force the speed controller to turn on. Some speed controllers are turned on by pressing the “M” button. Again, it depends on the e-bike model you have.

Be sure to check that your battery pack has at least two bars of power. An extremely low battery power level can lead to your electric bike not turning on, by the way.

Another thing to check here is that the electrical cables are correctly connected. Sometimes, the dirt roads can dislodge the cable connections; this is often the case with mountain electric bikes.

Water can find its way into these connections, too. Pull them apart and ensure the connection is tight.

eBike Not Speeding Up

There are numerous reasons why your electric bike isn’t speeding up.

often than not, the feedback magnets. positioned on the pedal crank or the rear wheel hub. for the proximity switch get dirty. Clean them with a rag, and you should be good to go.

This common eBike battery issue is often wrongly diagnosed.

Most quality electric bikes feature a switch on the back and front brakes to stop the drive motor. In some cases, these switches can get stuck. leading to their failure. Activate both brake levers a couple of times to try and free up the switch.

To check the limit switch, though, you might have to remove the whole rear or front brake lever. That’s another reason why you should avoid leaving your eBike out in the rain.

Also, while it might sound obvious, be sure to check if you’re in the proper mode. for example, pedal-assist, throttle-only, or pedal-only. I’ve sometimes found myself in the wrong mode, and I couldn’t figure out why my eBike isn’t speeding up.

There is typically a minimum speed that will activate the drive motor. That is just a safety feature. and it’s usually around 1.8 mph.

What Speed Are eBikes Limited To?

eBikes are limited to 25 km/h. or 15.5 mph. to conform to the majority of road rules around the globe. Once the motor reaches this speed limit, it will stop providing power further.

Of course, you can still pedal faster than 25 km/h, but you won’t get any assistance from the main motor.

Once the speed controller recognizes that you’re under 25 km/h, the battery management system will again supply power to the main motor. That is a standard component on most electric bikes. and, again, its role is to ensure that you conform to road rules.

Is 250Watts Enough For An eBike?

In most standard cases of use, 250W is more than enough power for you to ride your eBike on asphalt or dirt roads casually. A 250W drive motor is usually limited to 15 mph and can handle up to 240 pounds in rider weight.

If that doesn’t sound impressive, remember that you can always assist the main drive motor by pedaling.

You can always upgrade your bike with a Bafang conversion kit, though!


We can agree that e-bikes have come a long way since their first appearance. Granted, battery problems can occasionally happen, but most can be solved easily and quickly.

Hopefully, the tips I’ve outlined above will help you keep your eBike running fast. and for a long time. And remember:

The most significant danger to batteries of eBikes is excessive heat and low voltage. Make sure you keep your eBike battery topped up. and it will last for a very long time.

Can You Fix Your Electric Bike Battery?

Electric bike batteries are one of the most critical components of an eBike.The motor and many other features are limited once the battery no longer functions as it should. The first instinct that many eBike cyclists have when something goes wrong is to try and fix the battery since restoring one you have seems like it would be less expensive than buying a new one.

While it is possible to repair an eBike battery, especially if you only have a minor performance issue, the reality is that most eBike batteries aren’t worth the effort of trying to fix them. This is especially true when you have a severely damaged battery. Trying to fix it can cause you to get hurt.

However, because eBike batteries range in issue, we wanted to split our guide into two sides. First, we want to explain some easy tricks that will resolve the most common problems people have with their eBike battery. If none of these suggestions work, you’ll be at the point where replacing your battery is better than trying to repair it.

We hope our guide resolves your electric bike battery issue or at least explains why you’re better off getting a new battery rather than trying to make your old battery work.

Tip #1: Do a 24 Hour Full Charge Cycle

Like other batteries, electric batteries can sometimes enter a faulty, negative, or non-existent charge state where the battery doesn’t retain the full charge that your display says it has. This is one of the most common problems with eBike batteries. It can happen when you don’t use your battery for an extended period, when you ship your battery, or when you only charge your battery for a couple of minutes, or just randomly.

Fortunately, this is one of the most straightforward issues to fix with an eBike battery. All you have to do is leave your battery plugged in for about 24 hours. The constant feed of electrical energy over a day clears out any false or negative energy built up in the battery.

This also helps the BMS (battery management system) clear out any glitches it might be having. When your battery isn’t performing as well as you expect, letting it charge for a full 24 hour period is one of the best things you can do.

Tip #2: Clean Your Battery, Charging, and Frame Ports

If you have a removable battery, you’ll often be taking it off your frame so you can charge your battery indoors. While this is a great feature, it often results in crucial battery and frame ports being left exposed. Exposed battery ports then begin accumulating dirt, mud, and other debris that prevents your battery from being mounted correctly. This is why you might think your battery isn’t working properly when a failure to connect is the real issue at hand.

If you don’t think that your battery is being appropriately mounted, clean out the frame port and battery connection points to try and resolve the issue. Because you will be working with electrical components, make sure you use a safe or rated cloth for use with electrical equipment.

Typically, we use a dry microfiber cloth to clean out the charging and battery port when it’s getting dirty. While we usually avoid spraying anything on our cleaning cloth, but a small dab or squirt of a general cleaning solution can make cleaning a little easier. Be sure to follow the same tips if you don’t think your charger is connecting correctly!

Tip #3: Use a Multimeter Tool to Check Your Battery Voltage

If you’ve tried the above steps and you still don’t know what’s wrong with your battery, there is a way to check whether it’s worth attempting to fix or not. Using a multimeter measurement tool, connect your battery to the device to get a voltage reading for your eBike battery.

If you are within 80% to 85% of your eBike battery recommended voltage, then it is in good enough working condition that the issue is likely something other than the battery itself.

If your voltage is below 80%, you may have a blown cell, at which point your battery isn’t worth trying to salvage. While it might only be a couple of cells that are blown, installing new battery cells to pair with the old ones will lead to serious performance discrepancies that range from uneven charging to massive battery failure. Please consult the eBike manufacturer for warranty coverage if your battery is below 80% voltage despite having been given a full 24-hour charge.

Reason #1: It is Very Hard and Requires Multiple Tools to Do it Right.

Electric bike batteries are not only one of the most critical components on the eBike frame but also one of the most complicated. Depending on who you ask, the eBike battery may be even more complicated than trying to service and repair your eBike motor. Just to open a battery up without damaging the shell of the eBike battery can be an arduous process, requiring several tools to do it properly.

You have to be a skilled, experienced technician to successfully open, repair, and close an eBike battery without damaging it. This is a time-consuming process even for experienced eBike repair technicians, with the total parts and tools needed adding up to several hundred dollars. If you do it wrong, you can likely start a fire or cause some other issue that permanently damages the battery or even cause bodily harm.

Reason #2: It is a Very Expensive Process.

Due to the complicated nature of eBike batteries, many people send them to repair technicians to get them looked at instead of fixing the battery themselves. Depending on the issue, the repair cost may run a quarter to half the price of buying a brand new battery.

Even if you do it yourself, you’re still likely going to spend a lot of money just to get your battery working again. Cells, wiring, a soldering kit, and several other specialized tools required to fix significant eBike battery issues all add up. Cost alone is a significant consideration, but as we’re about to explain, you’re not getting much value for your investment as well.

Reason #3: You’re Likely Going to Have Persistent Battery Issues

Battery cells degrade over time, with BMS systems in your battery helping regulate and even out the performance differences as batteries break down. The problem is, BMS systems can deal with minor discrepancies between the dozens of individual cells within your battery. Once you pair a brand new battery cell with an old one, your BMS system has a much harder time trying to even out performance.

As a result, there are several different persistent battery issues common in eBike batteries with uneven cells. Disrupted and slower charging is typical as your BMS tries to feed different energy outputs to other cells. Sputtering or erratic motor problems is another, especially when you’re trying to use a motor with a higher energy drain. Worst of all, the new cells can cause the older cells to overload and explode, which will damage the battery and potentially start a fire. If you are replacing a few of the cells on a battery, you are better off replacing them all, at which point it just makes more sense to buy a brand new battery.

Conclusion: If Your Battery Breaks, Consider Upgrading Instead of Fixing

Being thrifty and doing your best to make the most of old equipment is an important virtue to have in life. It is imperative with eBike batteries since there isn’t a sound system in place yet to recycle and reuse old and broken down batteries.

However, while recycling and environmental awareness are important, staying safe and not causing fires is just as important. Due to the performance, cost, and potential harm caused by improperly repairing an eBike battery, it is highly recommended to upgrade over fixing serious issues.

As we noted above, there are minor issues you can resolve without resorting to opening up the battery. From our experience, these fixes troubleshoot the majority of battery issues reported to us by our readers. For serious battery performance issues that can’t be easily fixed, though, do yourself a favor and upgrade to a new battery to keep yourself, your bike, and other people around you safe while you ride.

Thank you for reading our blog post discussing eBike battery safety and repair. Please leave a comment below if you have any questions or if you want to know our favorite battery upgrades!

Electric bike maintenance: how to look after your ebike

If you’re thinking about buying an electric bike, you’ll want to know how to take care of it. The best electric bikes can be expensive, so to keep yours in the best condition you’ll need to have a regime of regular maintenance.

This guide explains how to look after your electric bike, including tips on washing the bike, applying lubricants, regular component checks, software and app updates, and looking after the battery. If you’re not sure where to start, our beginner’s guide to electric bikes will explain the ebike basics. The essentials of electric bike maintenance are the same whether you’re looking at an electric road bike, an electric hybrid bike or an electric folding bike.

Proper maintenance, particularly of the drivetrain, is even more important if you’re riding off-road, whether that’s on an electric mountain bike or an electric gravel bike, because dirt and debris can quickly take a toll on expensive components. An electric bike, like any bike, needs regular maintenance. Cleaning and taking care of your ebike will keep it running smoothly, efficiently and safely, all of which can contribute to a longer lifespan for the bike and its battery and motor.

How often should you service an electric bike?

In many senses, electric bicycle maintenance is no different from that of a non-assisted bike. However, some components, and particularly the drivetrain (cranks, chain and sprockets), are subject to greater forces and increased wear. Therefore, washing your ebike regularly and keeping it well maintained is of utmost importance if you want to get the most out of the bike. First things first, a clean bike is a happy bike. Dirt and mud increase wear on components and, when mixed with water and grease, can form a paste that will, at best, decrease the efficiency of your bike and, at worst, quickly wear through consumable parts. The smoother your electric bike runs, the more efficient it will be, and the longer your key components will last. Keep the drivetrain clean and running well: battery life and power output are irrelevant if your gears are grinding and skipping all over the place. Riding a bike with a clean, efficient drivetrain, along with correctly adjusted gears, is ultimately a more pleasurable experience and will help you get the most from the bike in the long run.

If your drivetrain looks excessively dirty (usually an accumulation of black gunk on the chain or, on electric mountain bikes in particular, mud stuck in the jockey wheels of the rear derailleur), you can give it a quick clean with a rag, or a deep clean with degreaser. We’ve got separate guides on how to clean a bike and how to clean a bike chain. Electric bike chains tend to require more frequent lubrication than non-assisted bicycle chains. Regularly applying a quality lubricant to your chain will ensure the transmission runs efficiently. It’s a good idea to do this after every ride, and certainly after washing and drying the bike. Otherwise, read our guide on how to choose and apply the best chain lube for your bike. Applying lubricant to an ebike sometimes isn’t as simple as it seems. You can’t back-pedal most ebikes, so try putting the bike in a workstand (or get a friend to hold the rear wheel off the ground) so you can turn the pedals to let the lube drip onto the chain evenly. If your bike has a ‘walk’ mode, you can engage it so that the cranks (and rear wheel) spin around slowly, allowing you to lube the chain easily.

Keeping your tyre pressures at the right level will help your ebike run more efficiently. Katherine Moore / Immediate Media

You should also regularly check your ebike’s tyre pressures. Under-inflated tyres are not only potentially dangerous, but they can also waste power and reduce efficiency, meaning you’ll get less out of a battery charge. Equally, running tyres at too high a pressure can compromise comfort and grip, especially if you’re riding off-road. As a starting point, keep your tyres inflated to within the recommended pressures indicated on the sidewall but experiment to find the ideal pressure for you, balancing weight, comfort, grip and rolling resistance. Want to know more? We’ve got guides to road bike tyre pressure and mountain bike tyre pressure.

Component wear and tear

Many ebikes now use components developed specifically for assisted riding. This means stronger parts made to withstand the added forces that go through an ebike, due to the increased power output, speed and overall weight of the bike. Electric bike drivetrains tend to be beefier and have different gear ranges from non-assisted bikes. Ebike-specific wheels and tyres are also sturdier, forks stronger, brakes more powerful, and so on. Nonetheless, despite this additional reinforcement, you are still demanding a lot from an electric bike, whether pedalling, braking, turning, climbing or descending, so it’s a good idea to keep a keen eye on the components and frame for loose bolts or damaged parts. Regularly safety check your bike to ensure that all bolts and axles are tightened to the manufacturer’s recommended torque settings, check your tyres for anything that might cause a puncture and test for any loose spokes. Watch out for excessive wear, too. If one part wears out, such as the chain, it can have a knock-on effect on other components – such as causing premature wear to the chainrings and cassette. We’ve got a guide to chain wear so you can spot any issues before they become a problem.

How to wash an electric bike

There are a few additional things to consider when washing an ebike. Alex Evans / Immediate Media

We’ve already covered the importance of keeping your bike clean to improve its efficiency and lifespan, but let’s take a closer look at how to wash an electric bike. Electric bike motors and batteries are sealed units and, therefore, shouldn’t let in any water, but you should avoid washing any bicycle – electric or not – with a powerful jet wash because the power of the water could force its way through the bike’s numerous seals. Wash your ebike with water from a bucket or low-pressure hose, a brush and (optionally) a bike-specific cleaning product to quickly cut through dirt and grime. Ensure that all connections remain sealed by leaving the battery in its housing, but turn the ebike system off before washing it (and unplug it from the charger). Charging ports can accumulate dirt, so check inside and brush out any mud with a dry cloth or brush. Keep the port closed when washing the bike. After washing the bike, dry it off with a clean cloth, making sure to avoid the disc brakes (you don’t want to accidentally contaminate them with any oil or other cleaning products used elsewhere on the bike). Every now and then you might want to give the battery contacts a clean. You can do this with a soft, dry brush, a cloth and (optionally) switch lubricant. If your bike has a range-extender battery (an optional second battery that can be connected for longer rides), you should always disconnect it before cleaning and clean the connections with a soft, dry brush. Your ebike may have a speed sensor magnet on its wheel. Clean this with a soft cloth to avoid any problems.

Waterproofing and repairs

Provided you’re careful, you’re unlikely to damage your motor when washing your ebike. Immediate Media

As mentioned above, the battery and motor of an ebike are well sealed to prevent any water damage. That doesn’t mean it’s absolutely impossible for water to get in, but with a certain level of common sense and care, you won’t need to worry. Things to avoid with an electric bike include using a jet wash and fully submerging the bike. No lake jumps then, sorry! The motor itself is in a factory-sealed unit and you should never attempt to take it apart for maintenance or to try and fix a problem. If it seems like there is something wrong with the motor or system, visit the store where the bike was purchased or take the bike to a reputable dealer. Some electric bike insurance policies cover loss or damage to your ebike’s battery.

Battery charging and storage

It may seem impossible to care for a sealed battery, but there are numerous ways to keep your ebike battery in tip-top condition.

All lithium-ion batteries gradually deteriorate and lose capacity over time. This might only amount to around 5 per cent of maximum charge per year, but is to be expected. Taking good care of the battery, storing it correctly and keeping it charged will help ensure a long life.

Ebike battery cleaning

If you disconnect your battery regularly, take the opportunity to clean it with a damp cloth and brush any dirt off the connections with a dry brush.

Clean and lightly grease the battery contacts occasionally, too. Never clean the battery with a high-pressure jet wash or high-pressure hose.

Charging and storing an ebike battery

Charge the battery at room temperature in a dry location. To improve the lifespan of your battery, avoid leaving the battery fully charged or fully discharged for long periods of time.

When the bike is out of use for an extended period, you can disconnect the battery. It will gradually lose charge, so still top it up every now and again.

As we’ve already said, avoid storing the bike for long periods of time with no charge – maintaining 30 to 60 per cent charge is ideal for long-term storage, according to ebike systems manufacturer Bosch.

If your ebike battery is removable, it’s a good idea to store it indoors when you’re not riding. Steve Behr / Our Media

Extreme heat and cold are the enemies of electric bike batteries. Store your ebike battery in a cool, dry place out of direct sunlight.

During winter, and particularly if the temperature is below 0°C, charge and store the battery at room temperature, and re-insert the battery into the bike immediately before riding.

Use the correct charger

While some battery chargers may seem compatible with several bikes, you should only use the charger specific to yours. Batteries don’t always charge in the same way, so using an incorrect charger could damage your ebike battery.

Software and app updates

Most ebike system manufacturers release software and app updates; some occasionally, others frequently.

As well as logging ride statistics and other useful information, some proprietary ebike apps or built-in displays can allow you to tailor the performance of your bike.

This might mean adjusting the power settings (so that, say, the maximum assistance setting delivers less power and, therefore, uses less battery) or acceleration characteristics.

Reducing the output settings so the battery discharges more gradually can extend the battery’s life, although you’ll have to work harder to get up the hills.

Many motor systems come with an app that lets you customise your settings and update firmware. Russell Burton / Our Media

You might also be able to get system health or maintenance updates from your ebike’s app or built-in display, which may show you information such as service intervals.

It may be possible to check if there are any firmware updates available through connected apps or by visiting the manufacturer’s website. Some brands recommend you visit an authorised dealership for any updates to be made.

Depending on the motor brand and system your bike is running, these firmware updates might help boost torque, extend battery life or provide other useful upgrades, so it’s well worth checking if there are any available updates for your ebike.

Finally, sometimes ebikes can display error codes that stop the motor from engaging. The reasons for these errors vary but can usually be easily fixed by a dealership.

Electric bike maintenance basics

Like any bike, looking after your electric bike will help you get the most enjoyment out of your machine, and can potentially increase the lifespan of key components.

By keeping on top of some basic maintenance, your ebike will keep you grinning from ear to ear. So, to wrap things up, here’s a recap of the basics of ebike maintenance:

  • Keep your bike clean, the drivetrain well lubricated and the tyres properly inflated
  • Regularly check for loose bolts, spokes and broken parts
  • Keep the battery partially charged and store it in a cool, dry place
  • Avoid storing the bike with a flat battery
  • Charge the battery only with the correct charger
  • Check regularly for software updates
  • Visit a dealership if there is a fault. Never try to take apart, or fix the motor or battery yourself
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How to Extend the Life of Your Bosch eBike Battery

New batteries are no longer that complicated, but here is a guide on how to extend the life of your eBike Battery focusing on the Bosch range of products.

The Basics

The 300Wh, 400Wh, 500Wh 625Wh PowerPacks used on Bosch-powered eBikes are amongst the most advanced batteries currently on the electric bike market. They offer a superior range, reliability longevity compared to many other batteries. However, this all comes at a price; with a replacement pack currently costing around £600. Some people are put off by the price of a replacement battery, thinking that it will have to be replaced every other year, but this is just not true.

Bosch actually guarantees their batteries for 2 years or 500 charge cycles (whichever comes first). This doesn’t mean your battery will pack up after 2 years and 1 day. In fact, Bosch themselves state that the battery should be good for around 10 years or 1500 full charge cycles. After 1500 cycles the battery will still work, but any battery will age over time so it will start to lose capacity and therefore not power your electric bike as far.

Also, it’s worth pointing out now that many people think that a part charge counts as a full charge cycle in Bosch’s terms. Unfortunately. it doesn’t! If you just top the battery up a small amount, only this is recorded and will not be counted until there are enough of these partial charges to count toward a full charge cycle.

As a registered Bosh eBike dealer, when a Bosch-powered eBike visits our workshop we can use our diagnostics tool to read the battery itself. The Bosch battery is a very clever unit and records many different parameters, these are then saved within the system for us to analyse and consider depending on any issues presented. Also, we can tap into the system and see exactly how many ‘Full Charge Cycles’ this particular battery has had. Furthermore, we can view many other variables within the Bosch software, for example – maximum/minimum battery temperature, charge state, usage, etc.

Here are some of the most common questions we hear regarding Bosch batteries:

If your eBike came from us, we normally charge the battery fully just before letting it out of the workshop as we know you’ll be itching to ride it the minute you receive it. This helps condition the battery and gives it a starting point from which to gauge the rest of its operation. If you find it’s not fully charged, please charge it to 100% before riding. This applies to all brands of electric bike batteries too.

How often should you charge your Bosch eBike battery?

The new Lithium cells used within the Bosch battery packs are very advanced. Unlike the older style batteries where you had to completely discharge the battery and then fully charge it back up again, the new Bosch PowerPacks do not need this. In fact, it’s much better to just top up the battery after every trip. So if you have just cycled 10 miles on your electric bike, it’s better to top it back up to full when you get home rather than incorporating a few trips before charging fully.

Can I still clean my bike?

Yes, as with any bike – it is good to keep all components of your eBike thoroughly clean. If the exterior case or shell of the battery and motor is dirty, which will happen, this does not affect the performance of the internals. The best way to clean the battery is with a specialist bike cleaner, wet sponge (or soft paintbrush!), and low-pressure hose. A typical garden hose is perfect for washing away grime without applying too much pressure, once the area has been lightly agitated with the bike cleaner and sponge/paintbrush.

Although the Bosch batteries are weatherproof, it is never advised to use any sort of high-pressure jet/pressure washer on your bike. This pressure can force water into the battery case itself and potentially cause damage. It can also force water into other parts of your electric bike where you don’t want water to be (motor, bearing internals, suspension seals, etc.). So although it may be quicker to clean please don’t use pressure washers at all.

Will my battery range be affected if using an inverter from my vehicle or motor home?

No, you can use inverters to charge your electric bike – for example – from the cigarette lighter port in most cars. This can be handy if you are out and about or wish to charge on the move. But please make sure that the inverter itself is rated for the correct output for the Bosch charger. You can normally find this information on the inverter’s packaging or on a sticker on the inverter itself. The Bosch charger is designed for a rated voltage between 207 – 264 volts with an output of 42v.

The charger only charges the battery at a low 4 amp current; this is fine for most inverters and car batteries. Please check these values to make sure the inverter is compatible before plugging it in. One point to remember is that depending on the inverter itself, the battery may take a little longer to charge than if it was plugged into the mains.

Most importantly of all make sure the vehicle engine is running whilst the battery is on charge because it could drain your vehicle battery faster than you think.

How you can extend the life of your eBike battery easily:

In very simple terms, the harder you use your eBike the faster the battery will discharge. You can maybe classify this as the trade-off between fun and economy! Remember, the power of the motor can peak at 500w (depending on the specific Bosch motor) so it can draw power from the battery quicker and put a higher load on it the harder you push, and the assistance required.

The faster it discharges, then the more you will be charging it back up. This means that you could end up performing many more charge cycles than someone who is using their eBike lightly in the same time period. After a long period of time, the capacity of the battery will gradually drop. You could, therefore, be in the position of replacing it sooner if you’re riding your eBike close to capacity for the majority of the time (this is especially prevalent in de-restricted bikes).

We would recommend using an assistance level that works for you. Quite honestly you don’t ‘need’ to use the eBike flat out in ‘Turbo’ all of the time (even though it is fun!). The use of ‘Eco’ ‘Tour’ modes for the majority of riding is generally more than enough, with ‘Turbo’ mode assisting on the very toughest of climbs or in tough conditions.

You can also utilise the eMTB mode on your Bosch system, which will vary the motor’s input depending on what you are putting in yourself. eMTB mode is always optimally adapted to you, the incline, and the terrain – regardless of rocks, roots, or steps. This will give you the most bike-like ride feel and will give you an even drain on your battery.

Obviously, everyone’s fitness levels are different so you will need to work out what works for you, it is far too easy to hit ‘Turbo’ mode for the majority of your ride. The bike won’t go any faster (mph) but it will have more ‘grunt’, in fact, the eBike will only go as fast as you pedal, it’s just the amount of assistance the motor gives you that changes.

I’m putting my eBike away for the winter, will this damage the battery at all?

No, we know that some riders may not want to cycle through the cold, wet, and grim UK conditions found in the winter. You can store your bike away, it’s not a problem, however, there are some steps you can take to keep your battery healthy during these times.

If you are keeping your eBike outside in a shed or garage, then it’s always best to bring your battery indoors. The Bosch batteries are capable of being stored in temperatures between.10 through to 60 degrees centigrade. But the cells don’t like to be stored in very low or very high temperatures. In fact, the best possible temperature for storage is room temperature – around 15-20 degrees.

Once in the house at room temperature, store the battery in a dry and secure place. Sticking it on a shelf in the kitchen above the kettle runs the risk of moisture traveling up from the kettle and into the battery case. So we probably wouldn’t recommend this as a location for storage! The perfect place is tucked away in a cupboard where it’s kept at optimum temperature, away from moisture, and where it’s not vulnerable to being knocked at all. We know it can make a very good doorstop, it’s tempting; but not good for your battery. Just make sure you remember where you left it when you come to want to ride it again…


When storing your eBike battery for long periods of time it’s best to keep the battery partially charged. If you store the battery completely flat then you run the risk of damaging the internals of the cells themselves. Also if you store the battery fully charged this can leave the cells under more pressure. So it’s best to keep the battery stored in between.

For the Bosch battery in particular the optimum charge state to leave it in is 60% (Or 3 LED’s lit on the battery level indicator). Try to check the capacity every 6 months or so. When the battery reaches 1 LED showing, then top it back up to 3 LED’s again. Many people think it’s best to keep the battery on charge so it’s always topped up in storage, but this is simply not the case. The Bosch charger won’t ‘overcharge’ the battery at all and does not trickle charge.

Will it harm the battery if I run it completely flat on a ride?

No – it’s never recommended to run the battery completely flat – but for longer rides, we know it can happen. The Bosch Battery is protected by its onboard BMS (Battery Management System). This means it’s protected for deep discharging, the BMS won’t allow the battery to run completely flat.

It may seem that you have no power left, but the BMS will have already shut off the power to the motor before it can hurt itself. We all know that the beauty of the Bosch drive is you can still ride without any resistance with the power switched off. On a side note here, if you are running lights directly powered from the Bosch motor and you do run out of power, the BMS will allow a small amount of power still to the lights so you will still remain visible!

I ride in very cold conditions during the winter, will this affect my battery life and performance?

The simple answer is yes. Similar to fuel MPG in a traditional car, Bosch says economy can be affected up to 30% in sub-zero conditions. So if you are consistently riding in these conditions it can really affect not just your range but will decrease the overall lifespan of the battery as well. There are certain actions you can take to prevent this, such as wrapping an external Bosch powerpack in a specific neoprene sleeve to keep it as temperature as possible.

Should I remove the battery when transporting my bike on the bike rack of my car/motor home?

Yes, this is strongly advised, put it in a dry safe place inside the vehicle. It is less likely to get knocked and lessens the chances of the battery flying off the bike on the motorway if it’s not secured properly.

The best place to store the battery is under the driver’s seat, this means it’s out of the way and also shouldn’t move around too much. Wrap it in a towel to prevent any knocks. Do not leave the battery on your parcel shelf, if you end up braking hard, the 2kg battery is the last thing you want hitting you in the back of the head.

Also, by storing it in the car it keeps the battery from getting wet. Although the battery is rainproof, people don’t realize that if you’re traveling at 70mph down the motorway, the water air traveling over your car is then doubled in speed as it wraps around the back of your vehicle. This means the battery could be being sprayed with water at around 140mph! This is stronger than a pressure washer and can force water into the battery and components of the bike itself.

I dropped my Bosch battery and the case is cracked, what shall I do?

If your Bosch battery (or any eBike battery for that matter) is damaged in any way, then it should be looked into being replaced. Even if it seems OK on the outside one or several of the cells inside may be damaged, this can then move on to other cells and the whole pack can become a ticking time bomb. The battery could seem fine and work but weeks later the effects of the damage could become apparent. The battery could heat up or even ignite in extreme circumstances.

Do not under any circumstances ship this battery anywhere. A faulty Lithium cell can reach temperatures of 1000 degrees. It’s really not worth the risk, visit us in-store and have it replaced.

So, how many miles can I ride on a Full Charge?!

Well this is the million dollar question we get asked over and over again. And to put it frankly, there is no one fits all answer to this question! You see, there are multiple factors at play which affect the distance capable on an eBike.

Tyre pressures, total system weight, type of bicycle, tyre tread, battery capacity, motor system, cadence, environmental conditions, riding mode, average riding speed and even road surface choice will have individual and then combined factors on what you can get out of your Bosch motor battery.

Bosch have a fantastic tool on their website, classified as Range Assist which can help you calculate the range for your next eike ride or tour. This takes into account all of the above factors, for you to determine by the sliding tools, and it will calculate the estimated range for you! Bosch Range Assistant – Here

When was your eBike last serviced?

Something as simple as a brake pad rubbing can slow you down considerably. With the extra assistance on an electric bike, you may not even notice the extra drag. But the motor will be working much harder to assist you and therefore will drain the battery faster. It’s best to get your eBike serviced at least once a year to keep it in good shape which can pay dividends to battery health.

I think my battery needs replacing, what shall I do?

You should visit a Bosch dealer and have the battery capacity checked properly. We won’t take a meter near it, we will plug the entire bike into our computers and be able to give you a decision straight away if the battery needs to be replaced. On request, we can also print diagnostics reports for your records. When a new battery is purchased it comes with a new Warranty from a Bosch dealer, so be sure to keep the receipt of the purchase date safe.

Remember if you treat your Bosch eBike Battery well, it will treat you well in return. We hope that this guide will help you to extend the life of your eBike Battery!

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