DIY 48v ebike battery. DIY 48v ebike battery

Use Your Cordless Power Tool Batteries To Power Your Ebike : What Could Possibly Go Wrong?

This article has been a long time coming, but first a little history. My wife and I have 2 houses, hers is 1.2 miles from the road up a 900 ft hill and has an off-grid solar system. She is also Chemically Sensitive so we don’t really have anything that runs with gasoline except our cars. Even the generator that we use in the dead of winter is converted for use with propane so we don’t have to deal with the hassle of gasoline. The lawn has a mind of its own (it’s not really a lawn, more like 600 acres of goldenrod) and we decided for our wedding reception we wanted to actually have a lawn for our guests. On her own volition without consulting the battery expert she went out and bought a 40v Electric cordless lawnmower (it was probably only 36v and they were just liars). 40v on a lawnmower was a joke your boss tells you that isn’t really that funny but you still have to laugh, so after a few attempts to knock down the overgrown weeds we just took it back. The next purchase was a much more expensive 500 EGO 56v cordless lawnmower which turned out to be all kinds of awesome. We quickly fell in love.

The mower was powerful enough to knock down most everything (including 3ft high goldenrod) and for the most part, the design was very solid. The 4Ah battery pack ran for about 30 minutes of hardcore mowing, but it also recharged in about 20 minutes and worked very well with our PV system as long as it was pretty sunny. This article is not a review for an overpriced cordless lawnmower that you will never buy. Instead, this article talks about a very Smart way to buy good lithium batteries with a built-in BMS and a decent warranty from your local hardware store, and then mount and use them on your high-power ebikes. Fasten your seatbelts because it’s going to be a hell of a ride.

A 4Ah Ego battery runs about 199 at any Home Depot store, Its a better deal if you buy it as a Chainsaw or Lawn Mower package.

I recently destroyed 800 worth of 6v Lead Acid Golf Cart Batteries from my wife’s solar system my setting them to equalize for 2 hours right before we left for 3 days to hike in the Catskills with visiting in-laws from Denmark. When we returned to the house it was full of smoke and the battery box was over 200 degrees and there was battery acid everywhere and the batteries were squealing and bubbling like crazy. So I donned an old Spinach container as a face shield and threw on some chemical gloves and carefully disconnected the batteries and carried them outside while trying not to get battery acid all over me. I did what any loving, supportive partner would do and agreed to pay for half of the replacement cost of the new cells (which will be closer to 1500) then I secretly sneaked away with her 500 lawn mower battery and went to my house for the weekend to extensively test them with my ebike.

Moral of the story : Don’t marry me if you want your batteries to live a long full life.

You can a fast charger (left) or slow charger (right) and 56v batteries in a variety of different sizes\weights and power capacities (2.0, 2.5, 4.0 ,5.0 7.0 Ah).

When is 56 volts not 56 volts? When it’s 52 volts

Another marketing misnomer is calling these packs 56v packs when really the rest of the battery industry would call them 50v, 51v or 52v packs, which is closer to the nominal rating of these cells. They are referring to peak volts fresh off the charger which is a hair over 57v, so you probably couldn’t actually sue them, but it sure is confusing. In any case, almost all the companies that make power tools are advertising their 14S packs as 56v so there you go. If you don’t like it then you should write a letter to some politician somewhere that they will almost certainly ignore (it’s their job to ignore you).

The battery and slow charger together are pretty heavy. The quick charger is even heavier (4lbs 4oz but not shown).

There were two ways I tested this battery, one with a modified charger (which was heavy) then I took the charger apart and just used the connector piece. I bought a used slow charger for 20 on eBay shipped. I think there are a bunch of them out there that were floor demos or something because the seller I bought from had 10 of them. I took the charger apart using a security keyed Torx (the ones with the dimples on them). Then I cut the leads to the positive and negative and soldered some wire and some Anderson 45 Amp Powerpole connectors to them. I covered the junctions with heat shrink tubing then carved out a tiny notch on the case. I wrapped the two wires with duct tape, put a small zip tie on there as tight as I could then tucked the zip tie inside the case to work as a kind of strain relief so the cable would not get ripped out.

Just a little snip and solder. This took me about 10 minutes to do.

I tried this configuration and it worked pretty well, although it seems silly to ride around with an extra 3 lb charger that you don’t really need. I took the charger apart again and then with two screws on the top I removed just the conductors to the battery. You can slide these conductors into the battery and they stay pretty well situated even when bouncing around in a backpack. The weight for just the connector was pretty nominal.

This zip tie will end up inside the case as a strain relief with the case biting down on the duct tape to protect the wire insulation

This battery pack did much better in the woods than I expected it to. I tested it pretty extensively with the BBS02 and the BBSHD without issues. The BMS can do 30 amp bursts but seems happiest running at 15-20 Amps. At these power levels, the pack does not even get warm. When the battery gets run down it will intermittently stop and start so it seems the low voltage cutoff on these packs is set very, very low. According to the marking for these batteries, they also are surrounded by a blanket of phase-changing material that will convert from a solid to a liquid if the batteries get too hot. I’m sure you remember from your physics class that going through a phase change like this absorbs a tremendous amount of energy from the surroundings, so this is the way they are able run these cells very hard, and still not worry about them overheating.

Using a phase change battery wrap is an ingenious way to capture excess heat

The BMS on the Ego packs is potted so it is completely waterproof, but the batteries themselves are well ventilated and the Ego packs are not really designed to be waterproof. The marketing video linked to below mentions someone leaving this pack outside for the whole winter under 7 feet of snow.

“See honey, there are people who abuse batteries worse than I do in this world. At least you’re not married to him.”

Personally, I would keep them in a waterproof bag or a backpack if you’re going to be riding in the rain or snow. Keep in mind I was testing with a 4Ah pack so you might find that the 2Ah pack does not produce as much power. I cannot find any specs on the packs rated output or the cells that they are using, but if I had to guess I would say the 2Ah pack is 14S1P 20R cells, the 4Ah pack is 14S2P 20R cells, the 5Ah pack is 14S2P 25R cells, and the 7.5Ah pack is 14S3P 25R cells. The 20R and 25R are incredibly reliable and widely used in the power tool industry for several years. They don’t pack the capacity of the newer 2016 cells like the 3500Mah GA cells that I’m crazy about, but they can put out 20Amps all day long without breaking a sweat. These older cells are also dirt cheap in quantity, and Ego is probably getting them for around 3 a cell wholesale.

This shows the pack\charger combo. When you press the button it lights up like some kind of crazy killer robot. The cake is a lie.

It is pretty cool to think that you can just buy a battery at Home Depot then throw your 3 lb battery into a backpack and get about 40 minutes of pedal-assist riding out of it. For a lot of people who just want to bang around town with a small ebike, the Ego packs might make a lot of sense. There are other people like Echo who are also creating 14S 56v packs that are quite frankly not engineered even close to what these Ego packs are. For an annoying Ego marketing video click here and for an independent 20 minute 56v Echo vs Ego pack teardown here. The Ego pack has a 3-year manufacturer warranty which is pretty much unheard of in the industry. That being said, if you buy an Ego pack and hook it up to your ebike, then it will certainly void the warranty.

The best way to use this pack is with the conductors just wedged into the slots

Should you spring for an Ego battery pack? In all honesty, if you had asked me yesterday I would have said ‘yeah go for it’ but just today I just ordered a newly released 6Ah 14S2P 30Q pack that only weighs 3.3lbs from Lunacycle for a scant 319 right here. At that weight, you will not find any 18650 pack that even comes close that will be able to do 30Amps continuous and has 6Ah of range. My large 21Ah 7P 30Q pack (reviewed here) does not even get warm pulling 50 Amps continuous so I’m certain that the 2P 3lb pack from Luna will be fine at 30Amps and less (and it has a thermal cutoff just in case). The pack is so small that it will literally fit in your with room to spare. The same could not be said of any of the Ego packs, even the 2Ah one which is pretty huge. I will be doing a review of this new Luna Mighty Mini 3lb pack as soon as it arrives so stay tuned, suckers.

The industry marches on as our old packs are quickly made obsolete.

Thanks to Ron\Spinningmagnets for the terrible idea to write this article. Ron both looks and acts like my Jedi ebike Master, but instead of saying wise things like Obi-Wan does, he is more like “Hey Karl, don’t be such a dick and maybe people will like you more”.

Is It Wise To Power My 48 Volt Mid Drive System With A 52 Volt Battery, Master Yoda?

thoughts on “ Use Your Cordless Power Tool Batteries To Power Your Ebike : What Could Possibly Go Wrong? ”

I bought one after getting the intro email. A lot of DIY builds don’t have an obvious place to put a battery, especially a large one. I’ve been using HK Lipos in a handlebar bag, small and light, on a step through. I’d be happy to retire those packs, but the Lipos have worked. These packs would also help to lower the entry point for new builders. The Smart Pie is a nice motor for around 300. Something like the SP and one of these packs plus a used bike? You would own a swell motor and a good battery. Like Like

Another great article, Karl! A few years ago, the only way to get high-amp cells was to gut cordless tools, so I did some reading on them. My first ebike was a DIY friction drive using RC model components, so they operate well on lower voltages. Oddly, the 28V packs used higher-amp cells compared to the 36V cordless tools. If I had begun making and selling friction drives to college students, I was going to use Milwaukee brand 28V battery packs, so I wouldn’t have 18-year olds burning down their fraternity dorms with LiPo. If I was designing a power-board today, I’d use those 28V packs and pneumatic tires… Like Liked by 1 person

Thanks Obi-Wan. Yeah nothing beats those 20R 25R’s for high output, cost and safety. The market drives the industry, the ebike stuff is just fringe and sometimes it feels like we’re all just along for the ride. Like Like

I’ve had an EGO for a couple of years and have wondered about using the battery as a range extender. I have a Catrike based velomobile with a 2000W MAC and a KW-hr of LiFePO4. I think my two bricks weigh ~20 lbs. I could toss my EGO battery in the saddle bags and extend the range 40%. Like Like

You guys are barking up the wrong tree, use 36v 4.4a hoverboard batteries, less than 50 bucks off ebay. Like Liked by 1 person

You are a braver man than I am Dan. Those cheap Lipos are notorious for spontaneously combusting. Like Like

Funny how we don’t really have what we want/need but always seeking what we can use and improvise. My 2 stroke 30yo lawnmower I had since a kid with barely any maintenance was getting to recon time. Wife always wanted to mow lawn and kid across the road was doing their lawn with electric like a cordless vacuum. I saw the 52-56V EGO used on a cruiser ebike (fugly, bulky with charge cradle used as the on-bike dock), we only had 4Ah packs available, so got that and the blower with 2Ah pack, with ebike use in back of mind. Really nice user friendly quality as you’ve shown in this blog. Too bulky for too low 4Ah capacity for ebike I thought, but the 7.5Ah sounds good, and the shared use mower/blower/ebike is the kind of quality battery sharing to help justify long term care and use. In the interim for suitable range the 16Ah 6S HK LiPo in a 12S pair fit in a lunchbox that fits in frame bag for similar size to the Ego 4Ah, but I can run only 50% discharge, 80-90% peak charge for longer life for most recreational use. I can use full capacity with 2 pair for 32Ah in duty standby for long range. Also provided auxiliary range to my Bosch system, and individually the 6S is a double capacity of the GoE OnWheel friction drive about to deliver from Kickstarter… So these 16Ah are good capacity and versatile across multiple ebike drives. Of the 4 cells I can use 3 for a 72V 16Ah pack in a direct drive hub motor kit as well. A DIY magnetic connector to the Ego battery spades would be handy. I hope the Ego products continue and we get the battery filter down. Like Like

Hey David, I didn’t quite follow but I think you’re using a different battery from the EGO, right? I’m curious about how you wired it into your Bosch system and whether you worried about using a higher voltage battery than the what the 36v Bosch wants? You haven’t figured out a way to use the Cycle Satiator with the stock Bosch battery, have you? Like Like

Here’s the Ego 2Ah to 4Ah to HK 16Ah lunchbox bulk comparison. Like Like

I was just at Home Depot and then checked out their and EGO’s websites. They tend to only carry the package deals in house. If you want a tool w/o battery and charger or just a battery, you have to order online. Does anyone have knowledge of the dimensions of the 7.5 A-hr unit? Like Like

Is there a picture of the bike this battery powers? Mortorcycle, airplane, whatever… let’s fire it up and see what she’ll do. Like Like

I would have never have thought of doing this. Since I was in the market for a battery, I went for the 7.5ah pack, its a really solid high discharge pack. I’m very impressed with it. Thanks for the top tip Karl! Like Like

Thanks Karl! Had just finished modifying a battery box from an ego mower into a battery mount, when my lunagizer went down and I had no way to charge my shark pack. (support has requested a replacement, thanks Louis!) But because of your inspiration I am still motoing! Getting about 4 real good miles, and another 1 1/2 weak miles from a 2ah battery. Got a charger, 3-2ah batts and the batt box for 180 delivered! Not an ideal solution to a spare battery, but it works and was cheap! Oh yea, the reason I went this route is I run a lawn care business and were switching to battery electric on all our small engine machines. Guess which manufacturer we use! Hehehe! Life is grand! Like Like

Sweet, yeah we’re loving the battery powered EGO tools. They are great. Got a chainsaw this weekend. Ready for the Zombie apocalypse now. Like Like

Is there anyway you can show pics of your setup as I too have 1 7.5ah one 4.5 and 3 2ah Ego batteries and am wondering if I should cannibalize either one of the 2 blowers I have or one of the 3 slow chargers in order to make a mount/connecting solution! email me at Like Like

So I’d like to use the Ego 4Ah Battery with this Front Wheel Hub Electric kit – is the 48volt hub motor controller close enough to the 50-52V actual provided from that battery? – Do I need any special adapters or converters (other than the charger connector piece/prongs)? – if the battery is 4Ah, and I assume 20wh/mile is typical, How many miles will this last on it’s own? Generic Add-on Motorize Bike 48v 1000w 26 Inch Front Wheel Electric Bicycle Motor Conversion Kit by Generic 4 out of 5 stars 52 customer reviews | 103 answered questions Price: 218.33 FREE Shipping Like Like

It might work, might not. Buy the kit and hook it up to a battery that reads 59v or so on a meter and see if it works before you buy the ego battery. In my experience there is a 90% chance it will work. Like Like

Nice and attractive cordless batteries also at a good my ebike is no longer looking sparenparts. Like Like

Ive just got the E-GO lawn motor and its awesome! I was able to mow 4000sqft and still have a green charge amount indicated! So I bought the 7.5ah today and 2 blowers that came with 2ah batteries and slow chargers and also have a 12 inch trimmer on order! I already have a couple stump-jumpers,KHS dual suspension, and a off road tandem that are all potential candidates for electrifying. I either want to go with a 1000watt rear hub or a bafang/8fun 1000w mid drive. I have a 8.1mile commute which I do now on my KHS road bike. Now how do I hook them up? do I cannibalize one of the blowers? for its clip in battery port? Like Liked by 1 person

I would take apart one of the slow chargers and then just take the tiny plastic piece that mounts to the battery and wire that up to your Ebike. It will work fine. Like Like

No it will not. You need a 52V battery for that kit, a 56v battery might also work. Power tools claim the peak charged capacity and the ebike world uses nominal battery. A 48v ebike kit means will need a 52v Power tool battery. It’s confusing and stupid, but the power tool pack makers want to make their packs LOOK more powerful than they really are. Karl Like Like

Hi! on a similar question, what do you think about the “affordable” panasonic of the mini pack mentioned in this article? ( ) And my newbie question is, can I use that pack for a mid-drive motor that says 500W continuous output (i THINK it is a 36V ebike?)? The previous battery that was used for this motor was a 42V10ah DIY 18650 battery pack that doesnt work well (dies halfway). i’m thinking of just buying a new one… Like Like

Check the voltage with a meter on the battery. I would not jump from a 36v or 42v to a 52v battery, you would be likely to burn out the controller. Most 48v ebikes can take 52v packs, but not 36v or 42v ones. Karl Like Like

No, the Greenworks is only a 36v nominal pack and in my opinion that is not enough for an ebike. I would not use anything less than 48v nominal (52v pack). The Ego packs work well and you can get them pretty cheap on ebay as store demos about 250 or so for a 7.5Ah like here. Like Like

What would you recommend for that battery? I’ve got a bunch of these GreenWorks 40V batteries and was hoping to hook one up to my bike Like Like

For several years these have been teasing me as this millenias potential “D” cell. The ‘waxy’ wrap etc. you report is why though however it is not it. A general purpose rechargable battery is still out of reach. The Washington Post this year i think reported on a mandatory leaf blow silencing effort in the beltway and noted the commercial battery price which was promissing! I have also been attuned to the forklift market as we folks like them live on ultralow voltages compared to cars duh. Recently phase change and compression storage system’s have begged the question we raise- which is if watthours not kwh’s are needed does ignorance of physics prove almost essential to disrupt? Yes and no! If by ignorance one means experience over dogma then absolutely! You don’t need a loan to buy dry ice to sprint to work with, and warm the globe little on a road bike versus any car even if coal powered steam versus hydrogen fuel cell. A person gets commuted for x amount of damage. So strapping several leaf blowers to your rear wheel cargo rack does not void there commercial at least use warranty per se right? Next year they should be blue tooth controllable fully. Presently it is legal to sell, buy, and use bikes that have us be dead ducks in left turn lanes should we see a car barrelling down on us- DESPITE compresssed air energy storage making a seat post capable of raising us out of collision reach Height an ample time an easy cheap defense mechanism. Synergy has yet to so occur. The electric car market is ruining a once in history opportunity to make people scaled vehicles regain road use. We do not have to concede or worse defeat outright ourselves. Moble energy storage needs to be traded like dirt only recently has been. Commodify it or in a decade cars will still be legal and act like they are as immortal as they have so far duped most into assuming. Human power prejudices are the greatest threat to life on earth. What home depot carries is all important. No entity will be condemned more historically then those like Optibike who should of not merely could of risked more to destroy the car market. Tesla if it was not pure evil could commodify the under hundred volt low KWH market, could pay it forward with same day warranty replacement etc. Mobility remain where cell phones where a decade ago- no standard charging port, cars being flipped two or three times in a year for there rebate etc. Assistance while we have more spent on oppressing us! We see in the nailing market internal combustion remains, yet no hydrogen combustion bike has ever been mentioned even as a concept to me. We have the right to augment human power with whatever can be frozen, burnt, ‘energised’. Nobody has ever worked on designing ridable machines rationally. This must change. Systems to accelerate, to offset rolling etc. Resistance, to anticipate or avoid or ridiculously suddenly stop should not have any parts in common, the price to unify such features has been planetary extinction because cars have Always been unaffordable to do at all right. Bikes now can be engineered correctly and even used publically STILL, but not for much longer. If it is not ALREADY too late any FURTHER delay WILL guarantee it never happens. We can kill car sized contraptions if we resist evil, if we demand access to off the shelf technology not be so taxed, deterred,obscurred, as is practically rejoiced in without exception. Thanks for recognizing the potential disruption of even illusory free market in human muscular drive evolution. I salute your losses. Like Like

DIY Electric Bicycle with 48V 2kWh Chevy Volt EV Battery

How to build yourself an electric bike? Learn the 4 components: types of batteries, motors, drives technology and bike choice that is currently available for those interested in DIY electric bike.

For short haul transport the bicycle has always been a favorite. But as we try to travel further, get older or become more unfit cycling is a difficult option. This is now changing with the use of electric powered bicycles. Unfortunately, as with any new products, there are some misnomers surrounding electric bikes.

How to Build Electric Bicycle

Each bike type has it advantage and should be chosen based on the riders needs.

ebike, battery

When related to weight, electric bikes are best stated as the less you get the more it costs. A full size aluminum electric bike weighing in at around 45lb will cost a lot more than a 90lb steel bike with lead acid batteries. It is also fair to say that the lighter the bike the more advanced the technology.

In addition to bike “off the shelf” electric bikes there is the option to buy a bike that better suits the rider and then ‘electrify’ it.

So what to look for? Let’s start with the more important factors.

Bike Frame

Ironically when people are looking for an electric bike the last thing they tend to look at is the bike itself. Bikes now come in a variety of wheel and frame sizes and gear ratios. There are also a number of styles of bikes. There is no point having the best drive technology if the bike is too heavy, too big, too high, uncomfortable, etc. So bike comfort should be the number one priority. For comfortable usage the following considerations need to be prioritized in order of, size of rider, size of wheel, weight, type of bike.

Nothing else matters if the bike frame is too big or too small. Bike frames range from 17″ right up to 24″ for 26″ wheel bikes. The frame height should be comfortable for the rider to stand feet flat on the ground and cross bar at least 1-2″ below crotch. If reasonable distances are to be covered then larger wheel bikes are the go. Consider two wheel sizes; on a 26″ bike a rider pedals to cover 8km approx, the same rider on a 20″ bike will only cover 6km approx due to less distance covered for each rotation of the wheel. This can be a significant difference in the course of a days ride.

Since the bike may need to be lifted, the lighter the bike the better. Therefore priority is to an aluminum/alloy frame. Finally there is the type of bike. The main types to consider here are the leisure bikes, cross bike, mountain bike or folding bike. Most people are more comfortable with leisure or cross bikes as they allow people to have a more upright posture, taking pressure off a bent back.

EV Batteries for Electric Bikes

The most expensive component of an electric bike is the battery. Skimp on price here and you will pay the price in so many other ways. There are 3 main types, Lead Acid (SLA), Nickel Metal Hydride (NiMH) and Lithium Ion. Forget SLA batteries, they weigh 3 times the other two types and do not perform well with heavy power draws for extended times. They are cheap, but it is false economics for electric bikes. NiMH weighs approx one-half that of an equivalent SLA pack.

The latest and lightest battery available is the Lithium Ion based cell. Lithium based cells are generally called Li-ion or LiPo cells. Until recently they were also considered one of the most dangerous batteries available. This was because of the volatility of the cell if it was charged or discharged incorrectly. There is a lot of well documented videos on these cells catching fire and exploding. However this hazard has largely been overcome with the use of better Battery Management Systems (BMS) and more importantly by the introduction of the Lithium Iron Phosphate (LiFePO4) cell. Lithium based batteries are the best if weight is the major factor. For safety repurposed EV (Electrical Vehicle) battery LiFePO4-based is the preferred choice, although standard Lithium based cells with a good BMS can also be considered. NiMH batteries are good value for a budget choice.

Greentec Auto recommends to repurpose EV battery from Chevy Volt. Chevy Volt 2kWh Battery Pack. Each 2kWh pack is 48V, 47Ah. Continuous current 240A. Peak current 350A.

13-2015 Chevy Volt Battery Pack and Modules Assembly, 36 month warranty


There are two types of drive system available. The most common is direct drive, eg. Hub Drive. The hub motor is located at the center, or hub, of the wheel and can be on the front or rear wheel. Direct drive hub motors vary the bikes speed by adjusting a throttle. Torque/thrust is inherently based on the motor’s drive speed and power. The other type of system is the gear drive system. This system has the motor drive the bike via the bikes gears. The bikes speed is adjusted by a throttled and its torque/thrust is controlled by the gears. The gear drive system tends to be more complex design and so is not widely available.

A hub motor is a quick addition to your selected bike, it is a simple wheel swap and cable connection. However, a common drawback to hub system is you are swapping out a good grade wheel for an unknown quality wheel containing the hub motor.

In addition a hub based system will not perform as well across the complete riding range of a bike. A gear drive system will offer better performance for a variety of terrain, especially hills.


Basically there are two types of motors, brushed and brushless (BLDC). Brushed motors have been around since motors were invented. They are reliable and reasonable efficient, around 70-75%. Although BLDC motors are a lot newer they are now seen as a mature, reliable alternative, coming in at around 80-85% efficient. Claims of efficiency beyond this are generically related to larger motors and not relevant to motors in the legally accepted power range.

The best choice here is the BLDC motor as the advanced electronics not only offer better efficiency but also protect the motor better. The other main consideration is that BLDC motors have no wearing parts aside from bearings. Brushed motors have wearable brushes and commutator.

Now that you know what makes an electric bike and what options you have you can decide what sort of electric drive system and battery you want on your electric bike. Do you want a pre built electric bike or a electric bike motor conversion kit? So are electric bikes the future? Countless people find a variety of uses for them in their daily lives, and as their advantages become more apparent more and more people are looking at electric bikes.

by Christopher Jones and Allan Dow @

Ebike Battery New Invention, 36V, 48V, and 72V Ebike Battery

Ebike Battery New Invention, 36V, 48V, and 72V Ebike Battery– This Ebike Battery New Invention is going to blow your mind; because using this circuit you can make 36V, 48V, 72V, or even a higher voltage Ebike battery. And I am going to share with you every bit of information, it’s designing, Proteus simulation, soldering, and practical testing. I know you might be thinking; why have I connected 4 battery packs? Why not a single battery pack? Is it cost-effective? Well, you will get answers to all your questions. So, let me start by telling you why I needed to make this in the first place?

Amazon Links:

Please Note: These are affiliate links. I may make a commission if you buy the components through these links. I would appreciate your support in this way!

Large battery packs like these are very expensive and for beginners, it’s hard to make a 36V or 48V, or 72V Ebike battery. Because connecting these so many lithium Ion Batteries in series and parallel combinations and then connecting them to a single BMS “Battery Management System” is the hardest job. I myself, when I built my first Trike Electric Scooter for performing some experiments; I used 4 Lead Acid batteries in series to get 48 volts. Of course, these were expensive and too heavy.

Anyhow, at that time this was the easiest solution that I could think of. Even with this easiest solution, the next issue which I faced was charging this 48V battery pack. So, I bought myself a 48V charger which is expensive and not easily available like 12V adaptors.

I ordered this online and then I had to wait for 3 days. Anyway, I performed all my experiments, first I started with a single Hoverboard BrushlessMotor, I successfully controlled it using a throttle handle and then using two 500Watts controllers I controlled two Brushless motors using the same throttle handle.

Next, I studied different Battery management system modules. And I built myself 3S and 4S Lithium Ion Battery Packs as these were easy to start withand moreover at that time I only needed 3S and 4S battery packs.

You can read my article on how to make 3S and 4S lithium Ion Battery packs, I have pretty much explained everything the connections diagram, welding using my designed spot welding machine and I have also explained how to do soldering if in case you don’t have a spot welding machine. So, if you are just starting with Lithium Ion battery packs then you should read my previous articles.

Anyway, after practicing for a while; finally, I was ready to make a 4S lithium Ion Battery pack for my Racing Drone as I was tired of using Lipo batteries. Lipo Batteries could hardly give me 5 to 6 minutes of flight time while my designed 4S lithium Ion battery pack gave me 30 minutes of flight time.

Based on my previous knowledge and experience, I built this 48V battery pack. This is cost-effective and can be easily built by anyone, and this 48V battery pack can be charged using a 12V adopter or a solar panel.

If you make a large 48V battery pack like this then you will need a 13S BMSwhich is available in the range of 3000 to 4200Rs on Pakistani online stores and it’s also quite expensive on Amazon. While on the other hand 3S and 4S BMSmodules are quite cheap. I am going to need four3S BMS modules which will cost me only 1600Rs or 7.17 USD. So, it will save me 2600Rs. And if you purchase these 3S BMS modules on Amazon then it will save you 50USD. Even if you search for the cheapest 13S BMS modulestill you will be saving yourself a lot of money.

So, using these 3S BMS modules I built myself these 3S Lithium Ion Battery Packs. You can read my article on how to make 3S and 4S lithium Ion Battery packs using 3S and 4S BMS modules. Anyway, now I can connect these 4 battery packs in Series to get 48 volts.

For this I designed this Semi-automatic control circuit. Its job is to connect all these batteries in series when needed to power up the Electric Bike or Electric Scooter and to charge the battery packs using a low-cost 12V adaptor. You don’t need a 50V or a high volt charger. A 12V and 3 to 4 amps adaptor is more than enough or if you want you can also use a solar panel. Now, you might be thinking how am I charging a 48V battery pack with a 12V adaptor? Well, it’s simple let me explain this by connecting all the 4 battery packs.

I have designed this circuit in a way that when this switch is OFF, all the batteries are connected in Series, and on the output, I get 48 volts.

And when I turn on this switch then all the batteries are connected in parallel. Now, I can use my 12V adaptor or a solar panel to charge all the batteries. At the same time, you can either charge the batteries or use them to power up the Ebike. This limitation is on the BMS side, I have already explained this in my previous video and article.

Anyway, this is a fully working prototype model. If you don’t like using the relays, then you can use power MOSFETs to implement the same concept. This circuit works with 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s, 10s, 11s, 12s, 13s, 14s, and so on. It depends on you how much voltage you need on the output.

When it comes to troubleshooting of this 48V battery pack it’s very easy. You can individually check each battery pack and if there is something wrong you can replace that battery pack with a new one or you can simply replace the faulty cell and you are good to go.

While on the other hand if one or more cells are damaged in a large battery pack then you will need to de-solder all the cells to find the faulty cells, which is really a tedious job.

Now, you know the advantages of this new 48V Ebike battery system, and now I am going to explain its simulation, PCB designing using Altium Designer, Online order placement on JLCPCB, Soldering, and practical testing. So, first, let’s start with the simulation.

V Battery Pack Proteus Simulation:

Before designing the PCB, I designed this simulation in Proteus. Let me play this simulation.

when the button is OFF the circuit is completely dead and on the output it gives 48 volts, right now you can see 44.4 volts but when the batteries are completely charged you will see 48 volts, I already demonstrated this. So, when the button is OFF the circuit consumes no electricity and you get full output as all the battery packs are connected in series.

When the switch is turned ON, all the batteries are connected in parallel and on the output you will see 11.1 volts. This voltage may vary depending on how much charge is available. Anyway, when the switch is ON simply connect your 12V adapter or solar panel to charge all the 4 lithium ion battery packs. So, after successfully implementing this idea in Proteus, then I switched over to Altium Designer for designing the PCB.

V Battery Pack PCB designing in Altium Designer:

Before creating the schematic and designing the PCB in Altium Designer, first I started off by searching the components on the world’s fastest components search engine Octopart. I selected the desired components with footprint models and used them for creating the schematic as per the simulation. I already have a very detailed video on how to make a schematic and PCB using Altium Designer.Anyway, then I switched over to the PCB designing document, I defined the PCB board size and re-arranged all the components.

Using Altium Designer you can automatically route all the wires. But I did it manually. I increased the width of the wires and I also applied solder to the top and bottom traces to increase the current carrying capacity as most of the current will be following through these copper traces.

I have used a total of six XT60 connectors. These 4 connectors on the bottom side are used to connect the four battery packs. From the middle one, we get the output to power up the Electric bike or Electric Scooter. And the one on the top is used to charge all the four battery packs using a 12V adaptor.

ebike, battery

Finally, before generating the Gerber files, I activated the 3D layout mode by clicking on number 3 on the keyboard. I double checked all the connections and once satisfied. I again activated the 2D layout mode by clicking on number 2 on the keyboard. Finally, I was ready to generate the Gerber files.

Generate Gerber Files using Altium Designer:

For this click on the file menu and then go to Fabrication Outputs and click on the Gerber Files.

On the units tab select Inches and on the Format tab select 2:3.

Then click on the Layers tab, by default no layers are selected, so click on the Plot Layers and select Used On.

Then click on the Drill Drawing tab and select Plot all used drill pairs in both sections.

Finally, click on the Ok button to generate the Gerber files.

Next, you will also need to generate the NC drill files. For this go to the File Menu and then to Fabrication Outputs and select NC Drill Files.

Select inches and Format as 2:3. Then click on the OK button to generate the NC Drill Files.

Now, I have the PCB Gerber files and the NC Drill Files. Right click on the project name and select explore this will open the project folder.

Open the Project Outputs folder, now, these are the output files that we need to send to the PCB manufacturing company.

Convert your Project Outputs folder to WinRAR before you send it to the PCB manufacturing company. As you can see in the image below.

Online Order Placement on JLCPCB:

For the Online order placement I am going to open the JLCPCB official website.They offer extremely cheap prices, you only need to pay 2 dollars for 1 and 2 layers PCBs of 100x100mm size.

For the same price, you can also order 4 and 6 layers PCBs of 50x50mm size. 5 PCBs for only 2 dollars it’s quite affordable. Besides this JLCPCB also offers PCB Assembly and 3D Printing Services. Anyway, drag and drop the PCB Gerber files WinRAR folder or Click on the Add Gerber File Button.

It automatically detects the number of layers and the board dimensions. Select the number of PCBs you want to order, you can change other details as per your requirement, in my case I am going to change the PCB color and everything else I will leave to their default values.Now, I am going to click on Save to Cart button.

These are the PCBs I received from JLCPCB. As you can see the quality is really great. The silkscreen is quite clear and the Black Solder mask looks amazing.

The components placement and soldering:

For the components placement and soldering watch the video tutorial on my YouTube channel Electronic Clinic or click on the link given at the end of this article. For the soldering I used the ATETool AE689 Soldering Station.

After completing the soldering, I double-checked all the connections using my Andonstar digital microscope. Anyway, you can see I am done with the soldering and as you can see I have also soldered all the 6 XT60 connectors. Now, I am going to connect a 12V adaptor to check if all the relays are working. Great! by turning ON and turning OFF the switch I am able to control all the relays.

Practical Testing:

The 500 watts Brushless DC motor controllers wiring I have already explained in my previous article on the Trike Electric Scooter. I am using the same 500 watts controllers, the same throttle handle, and the same Hoverboard motors. The only difference is, this time I am using a 48V Lithium Ion Battery Pack. So, let’s go ahead turn on the switch, and start controlling the motors.

This is simply amazing. I just built myself the cheapest 48V battery pack using low-cost 3S BMS modules. And I can charge this 48V battery pack using a 12V adaptor or a Solar Panel. And one more thing, if you want more current and more backup time then you can connect multiple lithium Ion batteries in parallel. So, that’s all for now.

The best electric bike conversion kits 2023 and how to fit them

The best electric bike conversion kits can give you an extra boost of power without the expense of purchasing a new electric bike. We’ve fitted some of the best e-bike conversion kits ourselves, so will walk you through the process, how easy it is and how the different systems perform.

E-bikes are soaring in popularity – and for good reason. The best electric bikes replace a car for running errands around town and greatly increase the distances it’s possible to ride on one of the best commuter bikes. An e-bike can also be a great tool for boosting your fitness, whether that’s enabling you to ride with a greater range of people or offering the motivation of a greater range of roads to explore.

But is an e-bike worth it,? As the best ebike conversion kits promise to add power to an ‘analogue’ bike for a lot less than a full ebike, it’s an easy, cheaper way to get an electric boost.

In this guide we’ll take you through the surprisingly broad range of benefits an e-bike conversion kit has to offer and – most importantly – how to perform an e-bike conversion, based on our hands-on experience. For a walk-through on how to do it, you can check out the video above or read on for a step-by-step guide – it genuinely is so much simpler than you would think.

When buying an ebike conversion kit there are a number of factors you’ll need to consider. Most importantly you’ll need a kit that will fit your bike. To help with this it pays to take a few frame measurements, notably the width of your forks and the width of the rear stays, as well as noting the wheel size and the type of brakes. You can then match these details to the kit specifications.

Naturally you’ll also need to consider the cost and how much you chose to spend on an ebike conversion kit will be dictated by not only your budget but also your needs. If you’re unsure of just how much you’ll use the converted bike then it’s prudent to opt for a cheaper kit. you can always upgrade down the road.

You’ll also want to consider where the motor will be located, and match this to your bike and your mechanical prowess. Front hub motors are typically the easiest to fit, while mid-drive motors require more effort. A rear hub motor lies somewhere in between the two, and like a front hub option is applicable to a wide range of bikes.

Other considerations include the type of battery and the wattage rating. 36 or 48 volt battery is standard, with wattage usually running from 300 to 600 watts.

The Swytch kit is super-simple: just swap out your front wheel, wire up the controller and battery and you’re off. The battery is also very compact, allowing you to remove it from the bike easily to carry with you.

The TongSheng kit positions the motor at the centre of the bike, so it will fit to a wide range of designs. It’s lightweight for its high torque and power output, although you’ll need to buy the battery separately.

The Voilamart kit is an inexpensive rear wheel conversion option, although you’ll have to source a battery separately. It’s slightly fiddly to fit as well and requires additional waterproofing if you plan to ride in wet weather.

The best electric bike conversion kits

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Our team of experts put in hard miles testing cycling tech and will always share honest, unbiased advice to help you choose. Find out more about how we test.


Wheel sizes: Each wheel is custom built – specify your required size at checkout (Bromptons also catered for)

Reasons to avoid

The newly updated Swytch system is one of the simplest conversion kits to fit out there. The latest version, launched in August 2022, has a smaller, neater battery pack that improves the bike’s dynamics and lowers its weight. There’s the choice of the Air battery (700g, range 15km) or the Max battery (1,100g, range 30km). Both use the same mount, which places the battery to the front of the handlebar.

The motor sits in the front hub and we found it to be pretty discreet. Incidentally, the new batteries will work with the original motor and pedal sensor, so if you already own the original kit you can upgrade it with just a new battery without having to buy the whole kit again.

The Swytch kit is incredibly easy to fit. It took us around 30 minutes working at a steady pace.

We tested it on both a reasonably light two-speed steel bike and a heavier Pinnacle utility bike. It transformed the ride of the two-speed bike, making it fast, nimble and responsive. We also found the stated range to be conservative: after 20 miles on setting number two (medium assist) it had only used two bars out of five on the battery.

With the heavier Pinnacle on maximum assist (and on draggy routes) we were getting slightly under the 30km for the Max battery. As with all e-bike batteries, range depends on the terrain, weight of bike and level of assist.

Great customer support makes this one of the best kits for people who are new to working on their bike and who aren’t familiar with electrics. And even if you do have a strong background in both those areas, a simple system is always appreciated.

Reasons to avoid

Like the Bafang mid-drive system below, the TongSheng offers the same benefits of compatibility with a wide range of bike designs and a high torque for steep hills and off-road terrain. However, the TongSheng mid-drive does manage to be a little lighter than the Bafang for approximately the same power.

This model doesn’t come with a battery included, so you’ll have to source your own 36v item. As a rule of thumb, around 10Ah will give a range of 29km / 18mi, whereas going up to 18Ah will typically give around 53km / 33mi, so be sure to factor that in when you’re making your choice.

There’s a huge range of batteries sold on Amazon, but Green Cell is a particular brand we’d recommend.

We found fitting to be reasonably easy. As with most mid-drive systems, you replace your crank and chainring with the one provided in the kit. There’s an LCD display for attaching to your handlebars and you’ll need a battery to be hooked up to the motor.

Read more: TongSheng TSDZ2 conversion kit review

Reasons to avoid

A mid-motor drive system offers a number of benefits over hub-driven conversion kits. With the power delivered at the cranks it can produce more torque, making it more effective on particularly steep and bumpy terrain.

Another perk is that the compatibility is much greater – no concern about wheel diameters, hub widths, axle standards and brake type. No matter whether you’re running rim brakes or disc, quick release or thru-axle, the crank driven system is compatible with all.

The only proviso is that the frame material must be alloy and the bottom bracket width is 68–73mm – but that covers most bikes you’re likely to be fitting this system to.

There are a few aspects to be aware of, the first being that this system doesn’t include a battery and that typically makes up about half the cost of a conversion kit. Finding an e-bike battery is quite straightforward with many being sold on Amazon, with Green Cell being among those we’d recommend.

Just make sure to get a 36V one for this motor as a higher voltage can damage it. Also you should be aware that capacity of 10Ah will give you a range of about 29km / 18mi, while a capacity of 18Ah typically gives about 53km / 33mi – so be sure to factor in the distances you’re planning on riding.

Reasons to avoid

This radically different approach from Rubbee makes for an e-bike conversion with much fewer parts. The battery and motor are housed in a single unit which powers the bike directly turning the rear wheel with its integrated roller.

Not only is the initial installation notably fast and easy, the quick release system means that you can take off the unit for rides that you don’t wish to be assisted on. At 2.8kg, it doesn’t add much weight to that of the bike, making the bike easier to handle.

The range of this model is quite low, limited to Eco mode it only offers a range of 16km / 10mi – although taking the device off to charge at the other end is easy to do and it only takes an hour to top up. There is the option to increase your range by buying additional battery modules that fit into the base unit.

Up to three can be accommodated, which in turn increases the maximum range to 48km / 30mi, or around 23km / 14mi with moderately heavy use. However, unlike many other e-bike systems, the Rubbee X supports regenerative braking, allowing you to scrub back some power on the descents.

Reasons to avoid

Bafang is a well established maker of electric bike motors and offers a front hub based motor, if you’re not a fan of the bulky profile a mid motor conversion system creates. You can buy this kit without a battery – although why would you? – but if you sensibly also opt for a power-pack there’s a choice of amp hours, and you can select either a downtube or a rear-rack mounted version.

The setup follows the same principles as most front-wheel e-bike conversions. First you need to set up the wheel with a disc rotor, tyre and inner tube and install that into the bike. Then attach the cadence sensor – so it can tell when you’re pedalling and need assistance – then attach the battery and the LCD display and you’re essentially good to go!

ebike, battery

It’s worth bearing in mind that although this conversion kit comes in many different wheel sizes, it is only compatible with bikes that have a front disc brake and a Quick-Release axle. If your disc brake bike is a newer, more expensive model, it might not be compatible, so worth checking first.

Remember, that in the UK electric bike laws mean that e-bikes are not permitted to have a power output of more than 250w and shouldn’t propel the bike when it’s travelling more than 15.5mph – you’ll have to make sure you select the right model with the relevant limitations.

Reasons to avoid

We’ve also tested the Voilamart kit, which comes with six main parts: the replacement rear wheel, the replacement brake levers, the control screen, pedal sensor, throttle and the control box. It doesn’t come with a battery however.

On review we found the kit pretty straightforward to fit, although you’ll need to remove the bike’s crank to fit the pedal sensor and this element of the conversion was a bit fiddly. Another potential drawback is that the connectors, which link to control unit, aren’t waterproof, with only a bag supplied to house the delicate electronics. While it does a good job of keeping everything tidy, we decided to buy a plastic enclosure, cut the wires to length, solder the connections and then heat shrink for added protection.

As for the ride, the rear wheel kit delivers plenty of power. However, since the pedal sensor only detects when you’re pedalling rather than how hard you’re pedalling it delivers the power as soon as your start to turn the crank arms. Fortunately, you can quickly adjust the level assistance, with five power options available.

ebike, battery

All in all the Voliamart rear wheel kit is an affordable way to ‘go electric’, although it requires you to be mechanical competent to fit it and you’ll need to factor in the additional cost of a battery.

How to convert your bike to an e-bike in four steps

Here’s our step-by-step guide to how to add an electric bike conversion kit to your pedal-powered bike.

Swap the tyre and tube

Firstly, remove the tyre and tube from your current front wheel and then install them on the new wheel from the kit. Make sure to check if the tyre is directional, if it is, ensure that the tyre is mounted so that the cable sticking out of the hub is on the left-hand side (non-driveside) when the wheel is installed in the bike – otherwise it’ll be powered in the opposite direction to your direction of travel!

To swap the tyre and tube over, you will need some tyre levers and a pump. If you want to go over how to do these, we have a guide that can be accessed here.

Final points are to do up the nuts on the wheel’s axle to keep it firmly in place in the forks and to check that the brakes are correctly adjusted for the new wheel. If you’re unsure how to do that, we have another guide here.

Attach the bracket to the handlebars

There is a strap that needs to be attached to the bars to keep the bracket in place and stop it rotating around. There are also some adaptors included in the kit which can be used if your handlebars are a little skinnier.

But essentially all that’s needed to be done here is a couple of screws to clamp the bracket tightly to the bars.

Attach magnet disc and sensor

The magnet disc has a split design so it can just clip around the inside of the left (non-driveside crank) and is then held in place by its retention ring. Next, stick the sensor on the frame directly in line with the magnets – this will ensure that the sensor can tell when the cranks are moving.

Plug in the cables

The thickest one is the main power cable and that just needs to be plugged into the cable extending from the hub. The other orange cable attaches to the cadence sensor and this just needs plugging in as well.

It’s then a good idea to use some cable ties to tidy up the lengths of the cables a little bit, so they aren’t flapping about and risk getting caught on the spokes or on the cranks.

The blue cables, you don’t need to worry about, these are for an optional brake sensor upgrade kit.

Why convert your bike to an e-bike?

What types of conversion kit are available?

You can get conversion kits that power your front or rear wheel or power the bikes via the cranks.

Wheel-based systems usually have a hub motor and require replacement of your existing wheel with a compatible motorised one.

The alternative is a system like the Rubbee that drives your wheel by pushing on the tyre. Tyre wear can be an issue here though.

Finally, there are systems that power the e-bike via the bottom bracket.

Usually the e-bike’s battery will bolt onto your frame or be attached to your handlebars, although sometimes you can fit a battery pack to a rear rack.

We’ve more on compatibility. which can be an issue. below.

How much does it cost to convert a bike to an e-bike?

vary depending on the type of conversion kit and the size of the battery. To give a rough Band, you can expect to pay a total of between £500 and £800 from a reputable brand, but there will be outliers at either end.

Is it worth converting a bike to an e-bike?

There are many reasons to upgrade your bike to offer a little e-assistance. On the one hand, it can greatly increase the usefulness of your bike, enabling you to replace short car journeys – such as around town, to the shops, or to work – with going by bike instead.

It’s a lot more environmentally friendly getting about on two wheels than in a two-ton metal box. It can also save you time – bikes are able to take more direct routes and are less affected by traffic, as well as eliminating the need to search for a parking space at the other end.

But beyond just their practical benefits, e-bikes can also be a potent tool for boosting your fitness. Consistency is key when it comes to exercise, so making commitments with friends is a great way to ensure you’re heading out the door. Previously, differing fitness levels could make it difficult to find a riding partner but with an e-bike levelling the playing field, getting in a productive workout (for both of you) with a friend is much easier to do.

Added to that, an e-bike can be much more motivating in that it opens up a far greater range of roads than you’d be able to access just under the power of your own two legs. Exploring new roads is part of the fun of riding a bike and an e-bike can help preserve that.

Can you convert any regular bike to an e-bike?

Most bikes can be converted to an e-bike – it just requires getting the matching the right conversion kit to match the specification.

For conversion kits where the motor is located at the wheel’s hub, you’ll need to consider the wheel’s diameter, the width and axle standard of the hub and whether it uses rim or disc brakes. For instance, a 700c (AKA, 28”) disc brake wheel with a 100mm wide quick-release hub is a relatively common spec. Once you’ve determined what type of wheel you need, the conversion is quite a straightforward process

Crank driven systems are generally easier in terms of determining compatibility; the requirements are typically just an alloy frame and a bottom bracket width of between 68 and 73mm – which is the standard for all road and mountain bikes, it’s only specialist bikes that have a different spacing there. In replacing the crankset, these systems are a bit more involved to fit than a hub system, but still well within the remit of a home mechanic.

Other kits, such as those that directly drive the rear tyre, have almost universal compatibility – provided your tyres aren’t too heavily treaded.

Are electric bike conversion kits any good?

You won’t be getting the very best motors and the largest, seamlessly integrated batteries with an e-bike conversion kit. But with that said, e-bike conversion kits are much cheaper than purchasing a whole new e-bike and they do deliver many of the same benefits.

Converted e-bikes are great for commuting and utility cycling, giving that extra boost to help flatten hills, motor along the flat and lug about heavy loads. E-bike conversions are also good for leisure cycling, helping to moderate your effort level as needed and greatly extending the range you can explore.

For more specialist utility needs, buying a new cargo e-bike would help boost your carrying capacity and range. Equally, for the aesthetically conscious, the latest breed of e-road bikes are almost indistinguishable from a non-powered bike at first glance. Then again, both those options are much more expensive than a conversion.

How we test

Where we’ve been able to link to a review, it means that we’ve put the ebike conversion kit through its paces. We’ve assessed how easy it is to fit and maintain as well other factors such as quality of the components and battery life and charge time. Riding the bike once fitted with the kit, we’ve taken into account the ride quality, the ease of use and the battery range.

Where we haven’t yet had the chance to review an item, we’re still confident in recommending it as one of the best, because we either know the brand really well, and have probably tested another product or the previous version and can still happily recommend it as one of the best.

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