Retrofitting a battery pack into an ebike.

Ok I was just looking at this ible. And noticed the type of battery the guy used.  So I did some googling and ended up here. Wondering to myself about trying to retrofit this type of battery into a veloteq challenger from 2008 or so. Remembering that its a 48 volt pack built from 4x 12volt lead acid 20amp batteries(cells) wired in series thus to stack the voltage and not the amperage.   Now I know amperage is simply a measurement of consumption so I'm guessing that these Yellowtops are way above the usual 20amp's that the veloteq asks for but I'd imagine that shouldn't make much of a difference.  Seeing as I only want to throw on two of these as to not blow way past  the weight restriction on the ebike itself by hitting 48 volts with four of these also to avoid breaking the bank with an 800$ purchase.  Could I not add some sort of transformer to step up the voltage to 48 volts or something like this? Any suggestions are welcome but I can't imagine this would really be all that bad of an idea.  I'd imagine it should boost the range somewhat if not a fair bit.  I'd imagine that my assumptions here are not far off but I'm here to either be validated or corrected. Or even educated if someone has any suggestions or advice.

Topic by chamunks 6 years ago  |  last reply 6 years ago

using a lipo charger to charge a SLA? Answered

Hey everyone ! I'm planning to use a lipo charger from my Ebike to charge some scooter SLA batteries. I'm more of a li-po guy and haven't tried charging 3 SLA's in series before. Original lipo was a 10s 8.8Ah 36V (nominal, maxed out at 42V) and had an on board BMS that took a stright 42V input from the charger. the charger for it will deviver 42V @ 2amp and will let current flow until it hits 42V then automatically shuts off. The scooter batteries are 3X 12V 20ah  (six cell I assume?) by all-means, I should be able to wire the three batteries in series, (3 x 14.5V = 43.5V) then my charger should be a direct replacement right? Still need to manually balance them occasionally but for daily use on a 2amp charge should be ok eh?

Question by Wired_Mist 2 years ago  |  last reply 2 years ago

DC motor with 30nm torque and more than 3000 RPM

Hi I need DC motor with 30nm torque and more than 3000 RPM how to build this or form where I can buy this in India please guide me on this also tell me what should be battery specifications to run this for 100km with the total load of 250kg?

Question by BhuvanS6 1 year ago  |  last reply 1 year ago

can i use 500 watt juicer and mixer motor for electric bicycle?

On motor specification it is written 500 watt , 50 hz ac motor , but when i plug it in 12 volt dc battery it runs slowly it can stop it with hand but i hope in higher dc volt it will run enough to use in my electric bicyle. it is philips juicer and mixer and grinder purchased from india

Question by Suraj Basnet 4 years ago  |  last reply 1 year ago

i want to build ebike?

But there is no any bldc motor supplier in my country Nepal, so anybody knows what alternative motor i can use to build my ebike that i can find from any other tools

Question by Suraj Basnet 4 years ago  |  last reply 4 years ago

is the 250 rpm dc motor is good for electric bike??

Is the 8kg-cm and 250 rpm dc motor is good for electric bike??  hi i have a 12v dc geared motor 250 : rpm 8 km-cm : torque is this good for build ebike ??

Question by ShocoM 3 years ago  |  last reply 3 years ago

Electric Bike Plans? Answered

Hey guys. I was thinking of building an electric bike this summer. The problem is I've never built an electric bike before and barely have any knowledge. I just wanted to know if it would be better to buy a ebike kit or to buy separate parts and build it. I have looked on Ebay for bike motors but i could only find up to 1000w kits for about 200-300 dollars and i thought that wasn't worth it. Is that the only price I can get a motor and do you guys know any good stores and sites to buy a cheap ebike motor. the other parts wouldn't be that hard to find so it's OK if you don't know of any kits. Thanks. P.s. I'm looking for Motors above 1000 watts

Question by amelaboy 7 years ago  |  last reply 6 years ago

What bike is this?

Hi, I have this bike and I have no idea what model it is. I was wondering if anyone knows what it is.,f_auto,w_620/v1495536303/fkejslljkduzq3ixdhbb.jpg Thanks!

Topic by Eileensmacircle 1 year ago  |  last reply 1 year ago

How to dismantle bicycle hub motors?

I need to open up the hub motor to repair the wires which have been ripped out of the hollow axle. I am reluctant to use force to separate the motor shell and it does not seem to want to separate after removing the allen screws. Which side is the best to remove? It is an ebikekit 500wat motor.

Question by etransport 9 years ago  |  last reply 9 years ago

How to disassemble the rear bike sprocket ?

I am working on an electric bike/ cart thing. I can either use an extremely small tire (scooter) and the chain that fits that sprocket, or a bike tire and sprocket. I have limited resources and money. I have an old rear wheel sprocket from a bmx mike. This was cut down about a year ago and was not done very well. The sprocket is not level. i was wondering if there is a way to pluck the center piece, i think it's the hub, out of the sprocket to just use the toothed part. without cutting or welding as i no longer have my grinder and have no access to a welder right now.

Question by NativeSs 6 years ago  |  last reply 6 years ago

Scooter Batteries: Can you wire 4 in series and 1 in parallel?

I'm selling my electric scooter to a neighbor who trashed his own. It's a virtually identical model aside from mine being a year older than his. he says his scooter runs on 5 batteries. Looking up the scooter parts info states, the control board and motor run off 48v. When I popped my scooter battery compartment lid open, I saw 4 12v batteries wired in series. So that's where the 48v comes from. Soooo could is be possible that the scooter batteries on the neighbors scooter are wired in 4 batteries in series to get 48v and one battery in parallel to add a bit off current to the total? 

Question by MilesT9 1 year ago  |  last reply 1 year ago

whats the chepest hub motor (500watt) out there?

Question by tazerl494 8 years ago  |  last reply 8 years ago

hlep! ebike question: how do you bolt the rear sprokect on the bike Answered

I am planing to use a 250watt motor to power my bike got it all figered out execpt how to bolt the rear sprokect?

Question by tazerl494 8 years ago  |  last reply 8 years ago

Has anyone created a Mid-drive electric bike?

Has anyone created a mid-drive electric bike?  I'm using parts from:;_id=29&osCsid;=uc9u80gtpmv25k2hgqcqjspgi1 but I'm looking for advice on the subject in general.  I'm adding a 600w geared electric motor to either a cruiser or a 700cc hybrid.

Question by jongscx 6 years ago  |  last reply 6 years ago

how many watts and hp can?

Question by tazerl494 8 years ago  |  last reply 8 years ago


I've bought 3 ebikes one a Raleigh select,p/assist, one a throttle type, but wires on 1of the other bikes I've bought,the wires that lead into hubmotor are cut they don't seem to connect via a hole in wheel axle/spindle,so need help please,also the p/assist Raleigh can it be converted to throttle powered, as its a very old ebike with a sanyo hubmotor? Thanks...

Topic by AlanW131 10 months ago  |  last reply 10 months ago

bike to trike no weld conversion? under $150?

can it be done just asking

Question by erjr5op 8 years ago  |  last reply 6 years ago

can we make truck engine starter motor last long time for gokart by rewinding it?

I want to use truck engine starter motor for my gokart or ebike project ? can i rewind it and modify it for long lasting

Question by Suraj Basnet 4 years ago  |  last reply 4 years ago

E-Bike motor selection, would it work? Answered

Im thinking of building an ebike, but unfortanately im stuck at the motor selection. I was just thinking, if you use 250W brushed motors for them, can this motor be used... If yes , just how to use it for a chain drive E-Bike? Any help will be greatly appreciated.

Question by robobot3112 1 year ago  |  last reply 1 year ago

charging 10s5p battery pack

I'm working on an ebike conversion. I'm buying laptop batteries to take out the 18650s and put them in my pack. I'm looking at a 10s 37v pcm. If I make it in 10 sets of 6 to get 37v 14.4ah, then how can I safely charge the battery so that they don't charge unevenly in each set?

Topic by leaf26 5 years ago  |  last reply 5 years ago

I am switching from SLA to NiCad on my e bike. I have a 48v controller, what options do I have? Thanks for having me!

Do I have to have exactly 48v of batts or can I use maybe 2 18v nicads? I was a music major, so when you guys and gals start using formulas to come up with amps, voltage. horsepower it blows me away.  Any information on where I could learn the basics would be appreciated.

Question by jackdullboy 8 years ago  |  last reply 7 years ago

I want to convert an old B&D lawnmower motor to DC. Answered

I'm going to build a Quadcycle from PVC pipe.  The plans are from American Speedster in Tallahassee, FL  The drive mechanism is from an old bicycle.   While researching my accessory options, I read about an electric conversion, built  from  an old B&d; lawn mower?   I don't have a cord long enough to continue the use of this  motor in it's AC configuration. ;=] Therefore, my quandary.  What is the procedure and what parts will I need to convert this motor to DC?  Also, I would like to know the difference in the wiring between different voltage ratings. I.E.  What determines whether the load drawn is 12 volts or 36 volts. Thank you a bunch!  Doug Olinger, Glennville, GA P.S. I have really enjoyed the information contained in the  Instructables on this site.  It is a great site,  and has great information.  I may try to create an instructable on this Quad.  It could be fun.

Question by DougOlinger73 8 years ago  |  last reply 8 years ago

Compact ight sensor switch with low voltage

Hi there,I've got a led light that's operated via a magnet, if it doesn't detect a magnetic field it turns on if it does it turns off. It's a led light for car door(check picture for reference) and uses 3x AAA batteries in my case 1.2v x3 (3.6v), if you use regular batteries it's 4.5vBy mistake I've order a tiny light sensor module 3.3-5v(check picture) which obviously can't be used as a switch, not in it's present form. While I'm good with solder, I've build an ebike, I'm a computer guy but when it comes to things like this like this make me feel powerless :( ..I 've used 12v light sensor switches but that's a different topic.So, how can I have a low powered light sensor switch that's compact and can save me from replacing the batteries frequent? ...the led light turns on even at daytime which has no point in doing that. I'd appriciate any help :D

Topic by Takisk1 11 months ago  |  last reply 8 months ago

FS: BIG electric motors

've got three 36v forklift steering motors. They're big, beefy, and used. Rated as 1 1/3 HP "special" duty. They draw 4.1A no load at 36v. With the gearbox, they draw 4.3A no load. Speed for the motor alone 3225RPM , with the gearbox is 75RPM. Torque must be something outrageous. They have an optional mating 43:1 Sumitomo-made gearbox which I reckon would make these some great drive motors for a large heavy project. Without gearbox, they would be excellent for go-karts, suicidal ebikes, etc. I even know of a e-car project that used a similar motor. (forkenswift) The motors alone weigh about 18lbs. Not sure what they weigh with the gearbox. You want one. I have three. I'm asking $100 each for the whole motor/gearbox shebang. Pictures:

Topic by nedfunnell 10 years ago  |  last reply 10 years ago

Brushed DC motor HP requirements for Longboard? Answered

So I have 2 brand new tilt/trim pump motors and thought about making a set of matching electric longboards since products like Boosted Boards seem to have become fairly popular.  I am not too sure whether the tilt/trim motor would be strong enough though, they are a decent size motor though.  But it got me thinking what size is required for an electric longboard? The main problem with the tilt/trim pump motors is that I can't find specs on them anywhere, just specs for tilt/trim pump assemblies they are off of, but nothing about the motor itself other then SAE J1171 Marine rating.  Because of this I thought of buying another DC motor to do the job.  (Picture of tilt/trim motor) The constraints for me is that I have a couple 12 - 24v 100A motor controllers already, for brushed motors only.  As well, I want to just pick up a couple cheap $40 12v, 24AH Sealed led-acid (SLA) batteries from the local Ace Hardware and run either a 12v or 24v motor.   Options on eBay for affordability purposes range from 12v, 24v, 90v and 180v dc, obviously 90v and 180v are out of the question.  Looking through the 12vdc and 24vdc motors, there are many fractional HP motors available.  I was looking at something like this;;=STRK%3AMEBIDX%3AIT Running 1/4 HP at 24v, would 1/4HP be enough though?  I know electric motors HP ratings are lower then petrol engines, a 6.5HP petrol go kart runs about the same as an identical kart with a 1HP electric motor. If that isn't enough I am thinking a 2/3HP motor from Holley might be better?;=STRK%3AMEBIDX%3AIT Wondering if someone has an idea for sizing.  I know lots of eBikes and Chinese electric mini bikes and things have 500W motors, so roughly 2/3HP, so I can't imagine I need more then that.  As well I don't want it to go too fast (fear of speed wobbles) but if anyone would have an idea of sizing that would be super helpful!

Question by Electric Spectre1 2 years ago  |  last reply 2 years ago