Ebike Controller FAQ – Everything you wanted to know. Ebike battery with controller

How to Remove and Replace an Electric Bike Controller?

Are you looking for a complete guide on removing or replacing an electric bike battery?

We are going to guide you now on removing and replacing the controller. The controller is the inside part of the brain of the e-bike. The controller housing is the battery slides into to connect with the controller. It gets power from the battery, but then what it does is it gets information from your LCD, and then it tells the motor how much pedal-assist or how much power to give you.

How to Replace the E-bike Controller?

We will take that outright controller now and then replace it. It’s a pretty basic job, and it’s not difficult. All we need are two tools of Phillips and some snips. All right.

  • We will go ahead and snip the wires free. They are held by zip ties in three or four places and snip those. There is one down here that goes to the motor. Of course, you want to be careful that you don’t snip the wire itself.
  • Now, we can go ahead, and there are two screws here in the front called Phillips. They are very easy to remove. One and two numbers hold the front panel of the controller housing, and in this black part, you will see a little plastic tab on either side. We can use the screwdriver to push those and pull that front panel out.
  • The front panel comes out, and the controller will come along it. We can pull that right out of the front, and there it is connected to everything.
  • To change the controller,we need to disconnect it from all the wires holding it still onto the bike to replace it with a new one. What we will first start with is we have two leads going to the battery tip. They are black and red like you may have seen in a car.
  • Now We will take the electrical tape off it. And then, the next step would be to pull the leads apart at the clips, which happens when you can pull on the tape just then. The red and the red go together, and then we will unbind the black one. We will remove those apart as well with the black leads.
  • And now, the controller housing is free of the controller. So, we just unplugged the rest part. We have this connection in the yellow one, which goes to the pedal-assist, and the next one is for the throttle. It has a little clip, you push down that little clip, and they will drop apart. And now, the last part is the longest than the others. There is one that goes down to the motor. We want to pull that part, and then there is one more zip tie right there, which is a little slippery.
  • The controller is free now. And then feed the wire that goes to the motor. We have to feed it through the bike’s frame. There is a little bit of cable management plastic right there, and you need to push that connector part through the frame, and there is one more zip tie. Some extra zip ties ones in; no harm it, and now, we need to move the other wires out of the way. And then, pull it right through the frame’s part it will come out. You will have the controller free of the controller housing and the bike, and then you can replace the controller.
  • Now, you can put the controller back in or the new controller, and now, first, you can connect the red and black lead. It’s going into the controller housing. They are very easy. They snap together like red and red, and then black and black are connected. Then next, there is yellow on that one, and you can match that up with the yellow one for the pedal assist. Put those wires between the rack arms.
  • There is also a little direction and directionality to the clips. You’ll see a little tab that will fit in there and little arrows. You can line up the arrows and then slide those back together.
  • The motor connection will have to be feedback through the frame. So, it will put it through between the seat stays and then down into the bike’s shell on the backside of the seat tube and push it. It is the trickiest part, just getting this part fed back through there. And then, this connection will go up to the LCD monitor and the brakes for the three-way part. Where is my connection?
  • Again find out the way that lineup. You can see a little tab, and there are also arrows, and it’s best to line up the arrows but do it very gently. You don’t want to hurt these parts. They are fairly delicate, and the connections are too.
  • And then, the throttle one’s very easy to see because it looks different than the other ones, snaps together with a nice positive snap. So then, now that we have the motor wire fed through the bike’s shell, line those two arrows up again, gently find the fitting, and then firmly push them together.
  • We have to put the controller back into the controller housing, tuck the wires away, and then the black wires coming out will be centered. And then, you’ll notice on the front plate of the controller housing that there is an opening area. Put where all the central wires are, click the front plate into place, the little snaps, and then we’ll secure it with those two little screws. Put in screw number one and number two, and that’s all there is. We are done.

Many well-known brand-name electric scooters and electric bikes have easy-to-install plug-and-play replacement speed controllers available in the market.

What if a Replacement Speed Controller is Not Available?

Most electric scooters and bikes have speed controllers made or wired specifically for that model. These speed controllers may only have connectors and wiring patterns unique to that model. Suppose a plug-and-play replacement speed controller is not available. In that case, a speed controller with the same Voltage rating and an equal or slightly higher Watts rating may be replaced for the original speed controller as long as it is wired to the other parts of the bike.

How To Install E-bike Controller?

If a speed controller is available, that will plug and play directly into an electric scooter or bike. However, when installing it, be careful because the connectors may be the same. However, the wiring patterns going to the connectors may differ from that of the original controller.

  • Double-check the wiring to ensure it is correct before installing the new controller. The pins can be removed and installed in different locations on the connector if the connectors are correct but the wiring going to the connectors is incorrect.
  • To rearrange the pins inside a connector, use a narrow metal rod to push on and bend the pins locking tab inside the connector, and then gently pull the wire and pin out of the back of the connector.
  • Now, turn the locking tab back to its original position and insert the pin back into the connector in the preferred location.

When the pin is fully inserted into the connector and the locking tab has been correctly bent back into position, it will make a small “snap” or “pop” sound to let you know that it has been perfectly installed.

Final Thoughts

We have tried our best to explain how to replace ad install the e-bike controller. If you still have any questions, comment below. We’ll contact you as soon as possible.

Ebike Controller FAQ – Everything you wanted to know

Before understanding how an ebike controller works, you must first understand what an ebike controller is. An ebike controller is a device that controls all electrical equipment on an ebike, it acts like a brain of an electric bike.

How to choose the best ebike controller?

We know that an ebike controller is the most crucial of equipment for an ebike. It is in charge of every aspect of an ebike. To have a smooth ride on an ebike, all components I.e. throttle, pedal assist, battery, electric bike motor, and brakes should work in a synchronized manner.

The intention of this post is to serve as a guide for ebike controllers and at the same time help you how to choose the best ebike controller. You will be able to do that just fine but first, you have to be familiar with the technical details about them to choose the best ebike controller.

What is the function of the ebike controller?

The electric bike controller gets the input from the display, throttle, pedal assist, battery, motor, etc, and provides instructions to the same ebike parts. This creates a communication loop and thus you can control the speed, acceleration, and battery usage of your ebike.

What are the additional functions of the ebike controller?

The electric bike controller works as the brain of the electric bike and synchronizes the operation of all ebike parts and provides a smooth ride experience. Apart from this main function, the ebike controller provides some additional features which also work as safety features as mentioned below.

  • Over-current Protection: If the motor takes current above the safe working limits, the controller reduces the current supply to the motor. This feature protects battery windings as well as the FET (Field-effective Transistors) power transistors.
  • Over-temperature Protection: The ebike controller keeps an eye on the temperature of FET. If they become too hot, the controller will shut down the motor to allow them to cool off.
  • Over-voltage Protection: The ebike controller also monitors the charge voltage of the ebike battery, if it reaches full charge the controller discontinues the voltage supply to the ebike battery.
  • Low-voltage Protection: While monitoring the over-voltage, the ebike controller also monitors low voltage, and once the voltage reaches its minimum threshold, it shuts down the motor. This protects the battery against over-discharge and increases the battery life by doing so.
  • Brake Protection: The controller gives the breaking signal superiority over other signals. For example, if you apply breaks and throttle at the same time, the controller gives priority to the breaking signal and the motor stops running.

What are the types of ebike controllers?

There are mainly two types of ebike controllers:

Brushed DC motor controller:

Brushed DC (BDC) motors are called so because they have the brushes that are used for commutation. Because its speed and torque are proportional to the applied voltage and current, a BDC motor is easy to control.

Key characteristics of brushed DC motor

  • Easy to control: torque is proportional to current – speed is proportional to voltage.
  • Moderate efficiency.
  • Variable speed: fewer external components are required than induction or brushless DC motors.
  • Maintenance is necessary as brushes wear out.
  • Louder than induction motors (EMI and audible).

Brushless DC motor controller:

Brushless DC motors have some significant advantages over their competitors, such as brushed motors, mainly because of the electronic commutation. It permits the controller to switch the current promptly and thus regulate the motor’s characteristics effectively.

Depending on the rotor’s placement, BLDC motors can be of two types:

  • The in-runner motor in which the rotor is internal, and the stator is on the outside of the motor
  • The out-runner motor in which the rotor is external, so the permanent magnets spin around the stator together with the motor’s case.

How BLDC motor controllers can be differentiated?

BLDC motor controllers can be differentiated according to the method they use to detect the rotor’s position. You can make the measurements with the help of position sensors or you could do the same by using a sensorless technique.

There are plenty of options among sensors, including:

  • Hall-effect sensors;
  • variable reluctance sensors;
  • rotary encoders;
  • Resolvers;

How Hall-effect sensors work?

Normally, a BLDC motor will have three Hall Effect Sensors mounted on the rotor or the stator. These Hall sensors are placed 120 degrees apart from each other, giving 0 to 360 degree angle position.

While rotating, When the rotor magnet crosses one of the sensors, it produces a low or a high signal depending on whether it is the North pole or the South pole of the rotor that has passed. As the rotor crosses all three sensors, these sensors switch between low and high, and by this data, hall sensors give out the position of the rotor every 60 degrees.

For more information on Hall effect sensors, please visit the post (https://www.embitel.com/blog/embedded-blog/hall-effect-sensor-and-its-role-in-a-motor-controller#:~:text=How%20Hall%20Effect%20Sensor%20Works,to%20360%20degree%20angle%20position.) on embitel.com

What are the advantages of Using a Hall Effect Sensor in a BLDC Motor Controller?

  • Hall Effect Sensor is a very simple device incorporating magnets, hence, very cost-effective for motor control systems.
  • For the same reason, these sensors are easy to implement in advanced motor control systems for EVs and other automotive solutions.
  • Most BLDC motors come equipped with these sensors.
  • Hall Effect Sensors are mostly unsusceptible to environmental conditions like humidity, temperature, dust, and vibration.

How sensorless BLDC motor controller detects the rotor’s position?

The sensorless BLDC motor controller, as the name states, works without a sensor; it detects the rotor’s position by estimating back electromotive force (back EMF). Back EMF is nothing but the voltage created in the stator’s windings by the rotating armature. By measuring the back EMF, you can determine the position of the rotor: the closer the rotor’s magnet, the higher the back EMF optical sensors.

How to choose the best ebike controller?

When you are on to choose the best ebike controller, you must choose from the list of controllers that are compatible with other parts of your ebike such as the display, the battery, the ebike motor, etc. Pointers are given below to help you choose the best ebike controller and stay away from those which are not suitable for your needs.

Power Voltage of an ebike controller

It is crucial to consider the voltage and power of your ebike motor when choosing the ebike controller. The controller can be Programmable or non Programmable. if you are selecting a nonprogrammable controller then you should match the controller voltage with your ebike motor voltage and Controller power with your ebike motor power. For example, if the voltage of your motor is 36 volts then you should select a controller of 36 volts

If you are going for a programable controller, the power can be reduced if required. The voltage of the controller should match the voltage of the ebike battery and ebike motor. This will reduce the heating of the controller and make the operation of the controller more smooth, which will ensure the long life of your ebike system.

The controller will have a published maximum voltage not to exceed. The panel, or panels, will have a label on the back with the panel’s specifications. The number you need to know is the maximum open circuit voltage. Sometimes called VOC.

Current rating of an ebike controller

First of all, what is a MOSFET? The full form of MOSFET is Metal Oxide Silicon Field Effect Transistors, so it’s basically a transistor that helps switch or amplify voltages in circuits. MOSFET can switch a few hundred milliamps to tens of amps, and single-digit voltages to thousands of volts. Generally, the maximum current for a 9-MOSFET controller is 25A, 18A for a 6-MOSFET controller, 40A for a 15-MOSFET controller, etc.

Note, though, that most controllers can handle more watts than needed without any problem up to about 150% but, the voltage capacity of the controller must never be exceeded. It will die an early death if this rule is not followed. Period.

Selecting an ebike controller amp is not a problem, you can go for the same amps as mentioned on your ebike battery. If you are unable to find the amps, you can simply divide the watts of your battery by the volts.

Battery amps = Battery Watts divided by Battery Volts.

For example, if your battery has 450 Watts capacity and a voltage of 36V, then the Amps will be 450W/36V = 12.5 A. So, you can go for a 12Amps controller.

Phase Vs Battery Current

The phase current and the battery current are two different things and people often get confused between them. The battery current is provided to the controller as an input that flows at battery volts, and the phase current is provided to the motor as an input by the controller. The controller will modulate the output voltage and the phase current can be much higher than the battery current.

The controller (sometimes called an inverter) takes the DC power and uses high speed-switching devices such as MOSFETs to generate three phases at current levels that can be controlled (to modulate torque) and at a frequency that can be controlled (to modulate speed). The motor phase current is very closely related to the motor torque.

Let’s take an example of the amplifier that is incorporated in many electrical devices such as welding machines. It takes an input of 10 amps and gives an output of 100 amps. The controller works with the same principle. It can take 20 amps from the battery and provide 60 amps to the motor as an output.

When you choose the controller you should give attention to the controller’s phase current. it should match the motor current because if it is greater than the current the motor is capable of normally running, the motor will start to heat more and more.

When the motor overheats, it damages the coating properties of the wires and the motor starts to overheat more because of internal short-circuiting, thus its life gets shortened.

Thus the face current of the controller must match the current capacity of the ebike motor for the prolonged life of ebike components.

Controller Driving Type – Sine wave Vs Square wave controller?

If you are using a sine wave controller you will get a smooth continuous push as a result for the entire journey while a square wave controller employs constant nudging or even jabbing instead of a continuous gentle push.

We can understand the difference by the analogy of two different bikes, one bike with round wheels and another bike with octagonal or square wheels.

ebike, controller, wanted, know

While both bikes will get you to your destination, you will get a smooth ride using the round-wheel bike on the other hand you will get a jerky ride while using the other bike with octagonal-shaped wheels.

You will not only be comfortable riding the bike with the round-shaped wheels but it will also get you to your destination quickly. While it will take much longer to reach your destination on the other bike, it will also be a waste of energy.

Sine wave controllers are famous for their low noise production. They provide you with smooth control but they cost you more, they consume considerably more power and they can work with matched motors only.

Many people prefer square wave controllers because they can function with different motors and are more affordable but they produce higher noise and they are not very efficient while climbing steep hills or pulling a heavy load.

Choose between a Hall Sensor/Non-Hall sensor drive or a Dual-mode controller?

If you have an ebike motor that has a hall sensor inbuilt then you should go for a controller with the hall sensor or a dual-mode controller. The hall sensor in the motor senses the number of rotations of the motor and the controller supplies the motor with voltage according to the signals from the sensor.

This type of controller is more stable and provides higher starting torque. If the sensor in a hall sensor controller gets damaged the controller prompts an error and ceases working but a dual-mode controller would continue working in a similar condition.

How much do ebike controllers cost?

Just like all the other electronic devices you can find both cheap ebike controllers and costly ebike controllers. You can easily find all kinds of ebike controllers on amazon, cheap ebike controllers (https://amzn.to/3XGrAE6) start at around 24 US dollars. If you want to visit Amazon to buy ebike controllers please use our affiliate link by clicking here

Can I repair a broken ebike controller?

Let me be frank with you here, if you are using a cheap ebike controller and it got broken somehow then you should get a new one instead of bothering about repairing it. It just doesn’t worth it.

If you decide to repair it yourself first you have to make sure that the circuit board is not damaged. If your ebike controller is damaged physically, there is a chance then that you can repair it but you have to invest first in proper repairing equipment such as soldering iron, the solder material, flux, and other equipment needed to do the job.

In case your ebike controller gets burnt off for some reason, probably it is beyond repair because normally, the tracks on the circuit board are greatly affected in this type of case. So, don’t waste your time and get the new one.

Can I upgrade my ebike controller?

You can certainly upgrade your ebike controller by tweaking it. There are lots of video tutorials available on YouTube that will show you how to do it. You can increase the phase current of an ebike controller as well as the voltage and you can get an increased top speed and acceleration by doing that.

ebike, controller, wanted, know

By modifying ebike controllers in the end what you are doing is providing higher current and voltage than the normal range upon which your ebike parts are built to operate frequently without any damage.

This is a dangerous game and even some ebike manufacturers are also playing it by using ebike controllers with higher current and voltage ranges. By doing this they can pass on their ebikes with lower watt capacity under higher watt range. For example, they can pass on a 450-watt capacity ebike as a 750-watt capacity ebike by simply replacing the ebike controller of 48V, 15A instead of an ebike controller of 36V, 12A.

If your ebike motor runs at higher watts than it is designed to normally run at, it will start overheating and eventually, it will burn out. That will cost you a big chunk of money.

So, we hope you have learned a thing or two by reading all that good information, please share this post as this took a big amount of time to bring all this information together.

Electric Bicycle Batteries: Lithium Vs. Lead Acid Batteries

When it comes to electric bicycle batteries, you’ve got two main options: lithium batteries and lead acid batteries. Sure, there are a few other types of ebike batteries out there, but the main two types you’ll see all over the place remain lithium and lead acid. Of course lithium batteries and lead acid batteries each come with their own distinct advantages and disadvantages, and knowing the difference will help you decide which is best for your ebike.

Lithium ebike batteries

There are many different types of lithium ebike batteries to choose from. I’ll give a short summary of the different types of electric bicycle specific lithium batteries here, but you can get a more detailed description as well as the pros and cons of each type of lithium battery in my article Not All Lithium Batteries Were Created Equal.

Lithium Iron Phosphate (LiFePO4)

LiFePO4 batteries are some of the heaviest and most expensive lithium batteries, but are also the safest and longest lasting.

Lithium Manganese Oxide (LiMn2O4) and Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)

LiMn2O4 and LiNiMnCoO2 batteries fall into the mid range of lithium batteries in terms of size, weight, safety, lifespan and cost. They are a good middle ground in nearly all regards.

RC Lithium Polymer batteries (RC LiPo)

LiPo’s are the smallest, cheapest, lightest and most powerful lithium batteries. Their disadvantages include short lifespan and propensity to combust into giant fireballs if not cared for correctly (I’m not kidding, check out the short video clip below).

Benefits of lithium batteries

Now that we’ve got the summary of different types of lithium batteries out of the way, lets look at how these lithium batteries stack up as a whole.

One of the first advantages of lithium batteries is their small size. You can fit a lot of lithium on a bicycle frame. This alone can give your ebike some seriously impressive range. Two or three mid to large capacity lithium batteries could easily fit on one ebike, giving potential ranges of 100 miles (160 km) or more. I guess this would be great for people that don’t mind sitting on their bike for three to five hours at a time, or that for some reason don’t want to charge up for weeks (hey, when riding your ebike through a zombie apocalypse, the last thing you want to be doing is searching for an outlet).

Lithium batteries made specially for ebikes often come with specific bicycle mounting points making them easy to bolt to the bike frame, seat post or rear rack. If you go with a different type of lithium battery without ebike specific mounts, you’ll likely have to put it in a bag on the bike, which is still a good option, and one that I even prefer sometimes. (Link to blog post of mine about center frame triangle batteries).

Lithium batteries are also small enough to allow you to place your batteries pretty much anywhere on your bike. This is especially true for people who want to assemble their own pack or use heat shrink wrapped lithium batteries instead of hard case lithium batteries with prefabricated bicycle frame mounts. This can help spread the weight around or hide the batteries to make a stealthier bike.

Lithium batteries (with the exception of RC LiPos) last much longer than lead acid batteries. LiPo batteries are usually only rated for a few hundred charge cycles but LiFePO4 batteries keep going after thousands of charge cycles. Every manufacturer rates their batteries differently, but most LiFePO4 ebike batteries will be rated for between 1,500 to 2,200 charge cycles.

Disadvantages of lithium electric bicycle batteries

A big downside of lithium batteries is that they are much more expensive than lead acid batteries. vary depending on the voltage and capacity of the lithium battery, but standard ebikes usually have lithium batteries starting in the 300 range and rising quickly from there. Most bikes I build have lithium batteries in the 400-500 range.

However, when you factor in the shorter life cycle of lead acid batteries, they become comparable to lithium batteries over the entire life of the electric bicycle. For example, a lithium battery may cost five times the price of a lead acid battery, but it could easily last five times as long as well, making the price about the same over the life of the lithium battery. You’d have to buy at least four replacement lead acid batteries (maybe even more) by the time your lithium battery finally kicks the can.

One other disadvantage of lithium batteries that isn’t talked about often, but should be, is their potential for theft. Lithium ebike batteries have become huge targets by bike thieves as a result of their combination of small size and high price tags (the same factors that keep shaving razor cartridges behind lock and key at the drug store). Thieves see an easy target and ample resale market, meaning you have to be extra careful about locking your ebike up and leaving it alone in public.

Lithium ebike battery partially removed from rack

Most lithium batteries that are designed to mount to ebikes also come with some form of locking system. These have varying degrees of effectiveness. The type with a little pin that slides into a thin sheet of steel are the easiest to steal by mangling the thin steel locking plate. Just take a look at your battery and ask yourself “how easily could I steal this battery if I had some basic hand tools and a 60 second window of opportunity?”

For this reason I like to either add a second lock specifically through the handle of my lithium battery (if it’s a removable style battery) or permanently secure it to the bike so it isn’t removable at all. The second option is less convenient because it means you have to bring the charger to the ebike, but it’s a much more secure option if you find yourself locking your ebike in public often.

Lead acid ebike batteries

When it comes to lead acid batteries for ebike use, you’ll generally be looking for what’s called a “sealed lead acid” or SLA battery. SLAs come sealed in a hard plastic case and can be turned in any orientation safely without leaking acid. This makes them appropriate for ebike use. Wet cell lead acid batteries, like many car batteries, would leak dangerous acid if turned on their side or upside down, making them a bad idea for use on an electric bicycle, which is a lot more likely to get knocked over than a car. Remember to stick with SLAs – not wet cell lead acid batteries – for electric bicycle use.

Lead acid batteries are much larger and heavier than lithium batteries, limiting their placement on ebikes. They almost never come packaged with ebike specific mounting hardware which means that they generally have to go in a bag on the rear rack or in panniers on either side if the rear wheel. Mounting them up high on the rack isn’t a good idea either because it will negatively affect handling. Generally speaking, you want to mount your batteries as low as possible to keep the center of gravity of the ebike lower towards the ground. This will significantly improve your ebike’s handling.

Advantages of lead acid batteries for ebikes

The biggest advantage of lead acid batteries is their price: dirt cheap. Lead acid batteries can be purchased from many different online retailers and local stores. Purchasing SLAs locally helps save on shipping and makes them even cheaper. Many hardware and electronic stores carry them. Even Radioshack has them, though you’ll pay more there.

Another advantage of lead acid batteries is their high power output potential. Lithium batteries generally don’t like to handle too much current. SLAs, on the other hand, can provide huge amounts of current. If you are planning a very high power electric bicycles, SLAs might be a good option for you.

Disadvantages of lead acid batteries for ebikes

One of the main disadvantages of lead acid batteries is their weight. There’s no beating around the bush here, SLAs are HEAVY, as you might guess by the inclusion of “lead” in the name. You’ll need a strong mounting solution on your ebike to handle the extra weight of SLAs. You should also be aware that lugging that extra weight around is going to negatively impact your range. The best way to improve the range of any electric vehicle is to reduce weight, and SLAs are kind of going the opposite way in that regard.

Another disadvantage of lead acid batteries is the shorter lifespan. Most claim to be rated for over 200 cycles, but in practice I usually find many SLAs start showing their age at around 100 cycles. They’ll still work as they get up in years (or charge cycles), but you’ll begin seeing your range quickly decreasing. If you were traveling 15 miles per charge when the SLAs were new, a year later you could find yourself barely getting past 10 miles.

SLAs come in 6V or 12V increments, meaning you have to build your battery pack by combining these smaller SLAs in series and/or parallel to get the specific voltage and capacity you’re aiming for. This can be both an advantage and disadvantage; it gives you more room for customization but requires some work to combine the individual SLA batteries together into a larger pack.

Who wins? That’s up to you

(…but it’s actually lithium)

When I’m experimenting with some new ebike parts and want to test different battery voltages for different speeds, I often use lead acid batteries because I can try many different voltages using very cheap batteries. Then when the results of my lead acid battery tests show me whether I want to go with 36V or 48V or 60V, for example, I then commit to buying the appropriate lithium battery.

There are only three instances where I recommend to use lead acid batteries instead of lithium

  • You are absolutely trying to build an ebike on a very tight budget
  • You are building an electric tricycle, which can easily carry SLAs without balance or stability issues
  • You want to test out different battery voltages on your system (make sure your controller can handle the voltage range)

For any other case, lithium batteries’ advantages greatly outweigh SLAs. Of course, for your specific ebike you might have other reasons that could sway you either way. At the end of the day, your ebike is all about you. I hope this information helps you make the right choice for your own battery needs.

About Micah

Micah is a mechanical engineer, tinkerer and husband. He’s spent the better part of a decade working in the electric bicycle industry, and is the author of The Ultimate DIY Ebike Guide. Micah can usually be found riding his electric bicycles around Florida, Tel Aviv, and anywhere else his ebikes wind up.

Комментарии и мнения владельцев

I have a GIO PB710/350w/500w bike. Is it possible to upgrade with a lithium battery? I mean Lithium battery will work with this or now?

Yes, you can upgrade a GIO PB710 with a lithium battery. You just want to make sure your battery is the same voltage as the original lead acid battery and that it can handle the current demanded by the bike’s controller.

Hi Micah, Do you have any charts showing the different weights by voltage for lead acid vs lithium? It would be good info to be able to see the penalty paid for cheap lead acid in a mid level build when compared to the equivalent lithium setup. I would prefer to go with lithium, but I have a couple of 75 volt (i think) cells from a UPS that are brand new. They are built from regular 12v (sixteen total) sealed lead units and would make the initial investment in an ebike that much more reasonable. One huge downside is that I hope to use the folding ebike in my homebuilt aircraft. As with ebikes, excess weight is to be avoided! As you sugested in one of your articles, using lead acid is a great way to prototype the build, so if I am happy with the performance if not the weight of the lead-acid, I can convert to lithium in the future and save some big weight. Thoughts? Jon

Yea lead acid is a great way to cheaply get into ebikes and test new motor/controller combinations. Keep in mind though that your performance will increase when you switch to lithium. It’s easy to do though, as the bike doesn’t care what chemistry it receives, it just sees volts and amps. Good luck!

Micah, I am new to the ofrum and to the ebike world so I would like to seek some advice please. I have recently bought a sondors fat bike to the UK and want to make some tweaks, I would like to upgrade the battery on a budget, I was thinking of 4 x 12v 5ah lead acid batteries in series, would this give me 48v 20ah or have I got this totally wrong? I want to replace the stock contoller for a 48v 25amp one, would this suffice? lastly it comes with a stock 350w bafang motor, if I make the battery and controller upgrades will the motor handle the increase in wattage? could I drill venting holes in the case cover to expell some heat? Your thoughts and advice would be most welcome, Regards, Wayne.

When you wire in series you only increase voltage, not amp hours. So you’d have a 48V 5AH pack in that setup. Not enough range, in my opinion. If you want my advice, the single best upgrade you can do to that bike is to replace the battery and controller for 48V units. It will give you about 30% more speed and power. You won’t need to drill vent holes or anything, that motor can handle 48V as long as you aren’t riding up any 5 mile long uphills with a 250 lb rider. Shorter uphills and flat land will be fine all day long.

Hello My friend I am having 36v lithium battery with 4.4 Ah(segway.balancing wheel battery pack ) but i want to convert this battery in to 36v with 9 ah is it possible to add one more 36v lithium 4.4 ah battery with this and i can use as 36v 8.8 ah battery. please help me iam not getting lithium battery in india for my e bike if am using SLA battery the distance coverage is very very less iam having 24v 250 watts brushless hub motor and 36v 500 watts hub motor please suggest me how and what battery i shoud use to cover atleast 25km thanks

You can certainly use a second 4.4AH battery in parallel to double your range, but you’ll want to make sure the batteries are at the same state of charge when you connect them in parallel, or use a diode in between them, to keep one battery from discharging the other if the charge states are unequal. The exact amount of range you’ll get per battery and motor varies greatly and depends on factors like terrain, speed, weight, etc. Suffice it to say though that if you double your current battery capacity, you’ll see an approximate doubling of your range as well.

Know Better About Your Electric Bike Controller

Ebike controllers are an integral part of electric bikes that you find around. It functions as the brain of an e-bike and maintains every aspect of it.

The controller helps you to control the speed of the bike, power from the motor, etc. In this post, you get to know about an ebike motor controller and tips to choose the right one for your needs.

What is An Ebike Controller?

An ebike motor controller is a specific component that connects the electrical parts to make the bike perform better. The device connects things such as display, throttle, motor, pedal assistant, battery. and other sensors.

In short, ebike controllers acts as the brain of your ebike. And, it manages all the functions of your bike effectively. In general, these controllers come in a protective sealed box. You can place the controllers on the bike just like an additional device.

However, certain controllers are designed in a way so that you can mount them inside the bike’s mainframe. That way, it stays hidden. Most controllers that you find around come in a sealed box for better protection.

How Does an E-bike Controller Work?

Fundamentally speaking, the electric motor in your ebike translates the electrical energy into mechanical energy so that the bike gets the necessary power to perform. The controller derives energy from the battery. It channels the energy to the motor based on user inputs and sensors.

When you twist the throttle, you can regulate the energy of the bike’s controller. As such, it helps you to control the bike’s speed. The ebike motor controller is responsible to keep track of the pedaling activity, battery voltage, power to the motor, acceleration, speed, and other important functions on the ebike.

over, it controls the pedal assist that you get while riding the bike. However, regional laws define the extent of whether or not you can use a throttle-equipped ebike.

Different Types of Ebike Controller Explained

Ebike controllers are categorized depending on certain criteria. Here are they explained.

Ebike controllers by motor types

Brushed DC motor controllers

These kinds of controllers come with permanent magnets along with a collector. Besides, the design of the controllers is simpler. The controllers are a set of keys that regulate the amount of current delivered to the engine.

So, more current means more power, and less current means less power. These kinds of controllers are common in e-bikes, scooters and light EVs. over, these controllers are easy to use and are a preferred choice for DIY enthusiasts and hobbyists.

Brushless DC motor controllers

On most e-bikes, you get to find brushless DC motors and controllers. They are brushless motors that have permanent magnets and offer higher efficiency and reliability. Furthermore, the service and operation of these controllers are simple.

Going by the structure, it looks similar to the brushed controllers. The BLDC motor controllers have three different phases. And, they are controlled by a set of keys. Also, they have a minimum of two transistors (key/MOSFET) per phase. Besides, the keys are like 6, 12, 18, etc., which are multiples of 6.

Ebike controllers by functionality

BLDC motor with hall sensors controller. These kinds of motor controllers are based on the Hall Effect. The BLDC motor controllers equipped with hall sensors help to determine the rotor’s position according to the stator. It is the motor’s fixed part and the rotor consists of the rotating part. Besides, it helps in determining the speed along with other attributes that are needed to run the BLDC motor effectively. Furthermore, the sensors are called rotary encoders that determine the rotor’s position.

Tips for Choosing the Right Ebike Controller

Here are the factors that you should consider before choosing the right ebike controller.

Controller current rating

When it comes to choosing the right controller, make sure that the current rating should be lower compared to the output current of the battery. In general, the maximum current suited best for a 9-MOSFET ebike controller is 25A. Whereas for a 15-MOSFET you need 40A and for a 6-MOSFET ebike controller, you need 18A.

Controller power and voltage

If you are looking for a specific controller with a motor, it is wise to check the power and voltage of the controller. When you are buying a non-programmable controller, make sure that the control voltage has the same voltage as the motor. Also, the controller power should be similar or a bit more than the motor power.

For instance, if the motor voltage has 24V, the controller voltage should have 24V as well. However, if it is a programmable controller, you can limit the extent of power if needed. Besides, the voltage of the controller, motor, and battery should match each other. Because of all this, the controller won’t heat and it would perform with stability. As such, it improves the system’s reliability.

Whether it’s a dual-mode controller, non-hall senor, or hall sensor controller

If the ebike motor controller houses a hall sensor, the controller will be dual-mode or hall sensor. The sensor detects rotation in the motor and the controller produces the voltage based on the signals from the sensor.

It has low power consumption and is more stable. Also, it has a bigger start torque. If the hall sensor isn’t working, the controller displays an error and discontinues to work whereas the dual-mode controller keeps on working.

Choose between square or sine wave controller

Both these types of controllers differ in voltage phase waveform. One will generate a rectangular waveform whereas the other one produces a sinusoidal one. The sine wave is popular because they produce low noise. Also, they provide great efficiency when you take your ebike uphill or carry the load.

Battery and phase current

You should ensure that the phase current and battery current are the same. When the controller provides current in excess to the controller, it will heat up more. The phase current in the ebike’s controller should match the motor current.


There is no shortage of different types of e-bike controllers on the market. Certain features such as voltage, control functions, controller dimensions, etc. are crucial for your ebike to perform better. Hence, consider the parameters discussed above when it comes to choosing the right one.

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