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First EV build

13K views 48 replies 12 participants last post by  nigelvan96 
#1 ·
Hey you guys,

I've been reading this forum for some time now and it got me interested in building my own EV. With the information i found here i got started on a first project.
The plan is to use parts from an old forklift to convert a cheap chinese build quad bike into a workable ev.
So mathematicly : quad + old forklift = EV1
I start this thread so everybody who is interested in the project can follow my progresss (hopefully i'll be able to finish it). It also gives me the possibility to ask questions and advise. Since i have very little to no experience in working with electric motors i know i'm going to encounter numerous problems that will need solving, so any help is more than welcome.

First i dismantled the motors and wiring from the forklift, got them wired up and working.
The pumpmotor specs are : 24v,3300w,185A comp
The drivemotor specs are : 24v,1250w cont, 75A, series
First problem, which motor to choose?
The pumpmotor is in good condition, powers up great on a 12v battery, should provide enough power to move the quad, certainly on a higher voltage.
The drivemotor i'm not sure, motor seems to have some friction when it starts turning, powered by a 12v battery. The specs are lower than the pumpmotor but the motor itself is a little bigger, has double brushes. Windings are very dirty, so i should probably clean it somehow before i use it if i go with this motor for the conversion.
 

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#3 ·
interesting build. your biggest challenge may be figuring out where the batteries go.

For the best range, a couple of 12V golf cart batteries (160lbs or so), for best performance, a lighter pair of 12V AGM deep cycle batteries (anywhere from 50 to 150lbs).

as for motor selection, the drive motor is more likely to be designed for continuous duty, but for your purposes it may not matter. probably the motor with the bigger brushes and bigger commutator would be the better bet. (better current handling capability).

the motors may have a splined output shaft on them, it could be fun to figure out how to interface that, but for quick and dirty, you can fit almost anything together if you just weld it.

Good luck.
 
#4 ·
Here are some photo's of testmounting the pumpmotor.
Its mounted without making any adjustments to the motor or chassis, just to see how much space it takes. The holes on de mountingplate of the pumpmotor correspond exactly with the holes in the chassis for the original motor, what a coincidence :)
I'm planning to do the same testmount with the drivemotor but for this i need to make some adjustments, its not going to be as easy as the pumpmotor.
My idea is to mount them both and see how they preform, first just with a 12v battery, then a second in series to have the 24v they had in the forklift. This with no controller, transmission mounted temporarily (probably with a quick weld as you said) to see which one moves the quad the most, maybe do a little spin round the car park, just by holding the battery cable to the battery. The most powerfull will be the one that i'll use.
The drive motor is a bigger series motor than the comp pumpmotor but i'm not sure about its condition. It has bigger, double brushes, windings are heavier but it just doesn't run very smooth. I'll post some pictures of it when i open it up to drill the holes for mounting it on the quad.
For the batteries i'm planning of using deep cycle gel batteries, 12v, connected in series to obtain the necessary voltage. First i thought of using 250ah,12v batteries, i could put 2 on the inside of the chassis easily but i think i'll first decide on which motor at what voltage to use (probably 48v) and do some testing before planning the battery pack.
The 250 ah batteries would be great for range, but they weigh a lot (about 70kgs a piece).If i use 100ah batteries(29kgs a piece) maybe i could fit 4 of them where the original ice and gas tank where, would be just fine, but that's something to worry about later.
I appologize if my english isn't a 100% correct, doing this conversion is actually a good exercise to freshen it up a little:rolleyes:
 

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#6 ·
Both of those motors seem a little big for your build. When looking for a forklift motor myself, I was looking for about a 9-10 inch motor ( 120-160 lbs ) for a mid sized car. I am currently working on a small dune buggy project, and I want with a 6.5 inch motor ( 50 lbs )

Just the weight of those motors are going to kill your range. Maybe you could consider trading someone who has a small motor and a car project?

Just my 2 cents

Twilly
 
#8 ·
Hey,
Thx for the replies guys, alway nice to communicate with people who share the same interests.
Its true that the motors are a bit big but i hope one of them will have enough power to provide a fun torquey ride.
The forklift they came from was already 30 years old with 7000 workinghours on its clock but easily picked up a load of 1000kg (approx 2000 lbs that is i think), so although the rating on the motors was a little dissappointing, they should both be powerfull enough to move the quad bike with me on it.
Range is not that of an issue to me, a rage of about 20km (approx 12miles) will do, but i would like good acceleration and a decent top speed, aiming for about 60mph (approx 90km/h).
The size of the motors is an issue because it is not easy to mount them firmly to the chassis, but i think the weight of the batteries matters more (4 bats weighing approx 30kg a piece = 120kg or about 250lbs) than the weight of the motor (about 60lbs).
For the moment i don't know how the motors preform, i first want to find that out. I don't know yet what i'm going to do with the spare (if they are both good, something i doubt very much).
I attached some photo's of the interior of both, windings and brushes.
The drive motor doesn't run as smooth as the pump motor, i noticed that the first time i tested them without a load. On the picture you can see that it is rather black on the inside, also i think the brushes aren't properly aligned, maybe this is the reason why is doesn't power up as well as the pumpmotor.
 

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#9 ·
I was not trying to talk you out of using the motor, That is part of the fun here. But keep in mind, you are using a motor larger than the warp9 I used in a Ford Contour. And my car had more get up and go than it did with the ICE... So imagine having a 200hp V6 on your 4 wheeler... Just be careful
 
#10 ·
Hmm, that would be nice :)
Just kidding, since this is my first build i have a lot to learn so any advice is much appreciated.
I'm planning of testing it (when i get it mounted with a proper chain transmission) with the wheels off the ground before i take it for a spin, i'll be careful, don't worry ;)
I don't know where you live but here in belgium it is not easy to get dc motors with controllers, i went to several shops but they all seemed very confused when i asked information, that's why i use these motors from an old forklift, a cheap way of experimenting and learning new things.
 
#13 ·
Did a testmount of the drivemotor today. Although it is quite big, it fits rather well in the chassis, didn't have to do that much modifications.
Also did some experimenting with it, it's a six terminal motor, so two fields, i wired them up in parallel and tested it with a 12v battery, wow, what a difference in running, smooth and powerfull.
The original forklift wiring used 1 field coil for moving forward and one for moving backwards, so half of the motor's power, that's probably why is rated so low on the tag, now i understand why people are warning me :)
I was planning on using the potmeter of the forklift as a controller, but that may also be a reason why before (using the forklift setup) the drive motor didn't preform well, should probably try getting a decent controller with twist-grip potmeter.
Next thing to work out is the chain-drive, should be doable, but i don't want to mess up the original chain transmission so i'll start looking for parts that i can adjust to my needs.
 

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#14 ·
First milestone achieved !!! Quad bike EV1 moved for the first time on electric power.
Because it was easier to fit a chain wheel to the pumpmotor i returned to this setup. Chain wheel fitted nicely to the axle of the motor. It was a bit of work to position the motor just right to give the chain enough room to pass to the rear but it worked out fine, didn't even had to adjust the chain length, the chain of the ice-transmission was just right, so far no problems, time to do some testing.
First test : 12v battery, wheels off ground : wheels started spinning fast, as expected, chain transmission works perfectly. Did notice an increase in amp use. No load motor only pulled 15A, with chain and wheels around 80A steady but a huge spike during the start. I guess it's normal.
Second test : 12v Battery, wheels on the ground, battery cable in my hand as a contactor : 12v was enough to move the quad with me on it, no exciting acceleration but it moved for the first time on electric power.
Third test : 2x12v batteries (strapped them to the sidebars) to get the 24v the motor had in the forklift : woooow, the added voltage makes a huge difference, this time a very good acceleration, maybe not as good as the 200cc engine but pretty close. For the first time i really felt the potential of the motor, this looks very promising.
The only thing that worries me is the huge amp draw on 24v, i didn't measure it (a bit tricky while test-driving) but the cable's i used from the forklift got quite warm, also the battery terminal suffered a bit of damage, i hope the contactors i have don't weld together.
 

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#15 ·
The only thing that worries me is the huge amp draw on 24v, i didn't measure it (a bit tricky while test-driving) but the cable's i used from the forklift got quite warm, also the battery terminal suffered a bit of damage, i hope the contactors i have don't weld together.
You'll be fine, you have to remember the contactor(s) will close before you give it any throttle. The controller will then be responsible for slowly adding that power and in a safe way. I did a bit of battery terminal "welding" with my 12v tests as well. :D

What size of cables are you planning on using?
 
#16 ·
The cables of the forklift where the motor came from are 30mm2, i was planning of using those for the conversion. If they get too hot i can double them for each connection. I'll also use the circuit breakers (300amp) that i recovered.
 
#17 ·
Here are some pictures of the contactors installed and a testmount of the auxiliary battery that'll be used to feed the contactor coils and all the auxiliary features.
It still needs some work but is seems this 45ah batt is the largest i can fit under the seat, should normally be enough to power contactors and lights for sufficient time. I used the contact switch to turn this circuit on/off and also wired the former starter button to power the coil on the main contactor. Wired this one to the motor so i could take it for a spin using the button as a throttle, not really a throttle, because driving this way is full power or nothing but this way i was able to control the motor a little better than before with the battery cables.
Test drive went really well, used 24v as before, contactor preformed well, no damage of the contacts although during switching it sparked quite a bit.

Later on, when i drove the quad inside, i noticed sparks coming from the motor's brushes and it smelt burned too :(.
Is it possible that some dirt entered the brush comm area? Or am i burning the brushes because i'm not using a controller?
 

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#18 ·
I'm still trying to determine what caused the arcing of the motor. Here are pictures of the 4 brushes, i noticed that the contact surface of the brushes isn't that smooth as before, all brushes have some form of 'pitting' (dark spots on the photo's), one more than the other where before they were smooth and shiny. Also the comm had traces of something i don't know what on it that wasn't there before.
My best guess is that during the testdrive some water and dirt splashed in the motor causing the arcing because the lowest brush is affected the most. I'll clean the comm, sand down the brushes' contactsurface with fine sanding paper (p1000 or so) so it's smooth again and let the motor run a while with no load on 12v to seat the brushes before i'll try it again on 24v. If this doesn't resolve the arcing i guessed wrong ...
 

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#19 · (Edited)
Jaguar is apparently planning to attack the upstart Fisker Karma head-on with an extended range electric version of the all-new XJ. The completely reworked XJ is due to arrive in July and hit dealers in December with a look heavily influenced by the smaller XF. A year later, the Indian-owned British luxury automaker will reportedly launch a plug-in version with 30 miles of electric only range that should help the big car get 47 mpg (US) and a CO2 emissions rating of less than 120 g/km.

Jaguar will be able to introduce this new model now that it has approved for a new EU loan for developing greener cars. Jaguar already has an advantage over some of its competitors because the full-size XJ is comparatively light thanks to its aluminum construction. Lotus Engineering and Caparo are helping Jaguar with development of the ER-EV powertrain.

Additionally, Jaguar and Land Rover are rumored to be developing micro-hybrids, full parallel hybrids, smaller diesel engines, and boosted gas engines along with even more weight reductions for the full lineup.
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#20 ·
Got the brushes out, sanded them down an tried them on the motor. Arcing is a little less, but still present, so it wasn't just a little dirt in the motor that caused the problem.
While i was sanding them down i noticed that there are tiny cracks in the brushes too and the brushes are a little colored near the contact area what it my opinion means that they got really hot (perhaps near melting point, what would also explain the traces on the comm).
Maybe it's the combination of high current and old age (i guess they are about 30 years old) that caused them to fail.
I have some big enough brushes lying around, i'll modify them to fit the brush holder of the motor. These have a different composition than the original ones, they seem harder (more dense material) and are not pure carbon (have more like a dark silver color instead of black), maybe these ones better handle high currents, i'll find out soon.
If anyone has some experience with brush problems, feel free to comment.
I'm also e-baying to get a controller, thinking of buying an alltrax AXE4834 programmable controller so i can adjust it to my needs, in this case limiting the current so i don't burn brushes all the time.
 

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#21 ·
Hi, my first post :)

I have a similar project on the go. I have a 24v pump motor from a forklift, and an even cheaper quad (swing axle suspension rear AND front, and it came with a 49cc engine that just about got me up to 15-20mph.)The problem is I'm having a little trouble with the motor, as the end bearing is mounted in the pump. But when it's done I'm going to fit a sound system and flood lights and it becomes... PARTYQUAD!

Good work there though! RE the brushes, if you have a friend with a lathe you can cut a tiny layer off the commutator (colour it in with a sharpie and cut it until all the black is gone), and replace the brushes and springs. Then run it at 12v so they bed in, and it should be much smoother.
 
#23 ·
For the moment i'm using a ratio of 14/37, selected this ratio because i got the front chainwheel cheap from the local bike shop and it fits the axle of the pumpmotor rather well without modifying it.
You're right that a smaller ratio would lower the ampdraw at start, certainly the duration of it, also it would add acceleration what would be nice but lower the top speed.
The wheels of the quad measure about 40cm in diameter, so 1.256m/rev. When the motor runs at 2000rpm i should get about 750rpm on the wheels with current gear ratio that should result in a top speed of approx 56km/h (35mph), assuming that the motor gets up to 2000rpm so not calculating drag, which is lower than what i aimed for but for the moment i could live with that.
With the wheels off ground i measure a huge ampdraw at startup (my meter goes OL) but it decreases after a few seconds to stabilise at about 50 amps, with no load it stabilised at 15 amps, motor is rated at 185 amps. With the wheels on the ground and me on it it will draw a much higher current but i haven't measured it.
The owner of the forklift i got the motor from told me today that the motor smelt burnt before so it is possible that the brushes were on their last legs already, not impossible, i think they are as old as the forklift, that's 30 years. Me hitting them with a ton of amps clearly finished them off.
So it looks like i have to replace the brushes, i'm modyfing some i had (2 finished, 2 to go) and let them seat running the motor on 12v with no load so they make good contact with the comm, normally when they are properly seated arcing should be gone. For the moment i'm not going to work on the commutator,cleaned it with a rag, but i'm no specialist so it is certainly something i will keep in mind in case the arcing continues.
I think that it would also be sensible to use a controller next time, so i can control the current at start up, now the motor draws all the amps he can get from the batteries and i don't think its good for either of them.

The pump on the pumpmotor i use was easy to remove, only had to loosen 4 bolts to get it off and used a small angle grinder to remove the support it was mounted on. If the endbearing is in the pump itself it's a little more challenging. You do have to see if the axle exiting is long enough to hold some kind of transmission. Also look if the motor has some kind of cooling fan in it.
Nice to see someone with a similar project :) If you make a building/conversion thread i'll certainly follow along.
 
#24 · (Edited)
The pump on the pumpmotor i use was easy to remove, only had to loosen 4 bolts to get it off and used a small angle grinder to remove the support it was mounted on. If the endbearing is in the pump itself it's a little more challenging. You do have to see if the axle exiting is long enough to hold some kind of transmission. Also look if the motor has some kind of cooling fan in it.
Nice to see someone with a similar project :) If you make a building/conversion thread i'll certainly follow along.
Unfortunately the shaft is only just long enough to protrude through the bearing, and that's with the output yoke I found inside the pump! I might extend the shaft, it's not too much trouble to mill up a new one, but then I have the problem of mounting the gear. There's no fan on it either. I could machine up a new endplate, but I have been advised to junk it and try again. It also needs new brushes and springs (AFAIK the motor was thrown out originally because of 1 broken brush spring!).

I know once I get the motor mounted, and the quad stretched it'll be plain sailing. I have a garage full of car batteries, and I'll use 4 in a 2s2p arrangement. I think I'll be OK using a relay to switch the motor...
 
#25 ·
Hi guys, a little update.
I abandonned the idea of using a large auxiliary battery, it's much easier to install a small dc/dc converter to keep the original starter battery fully charged, won't be using that much auxiliary power anyway.
I'm also trying to figure out which batteries i'll buy and how to mount them because there isn't much space. Initially i thought of using 250ah 12v gel batteries but they are way too big to fit, still something to think about ...
Somebody heard of this company http://www.evdrives.com/index.html ?
 

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#26 ·
Below is a picture of the dc/dc convertor to aux battery setup. Works really well, keeps the battery charged at 13,8v when the battery pack is connected.
Also installed an hour meter to keep track of running time.
I'm seriously thinking of installing a new motor with controller, what do you guys think of this http://www.evdrives.com/mars_motor_me0708_etek-r.html.
 

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#27 ·
In recent test i burned the brushes, now i fitted new brushes and tested it with the potmeter that came out of the forklift as a controller.
It's a simple system, a bit big to mount on a quad but i tried it nevertheless.
It has 3 positions, in first is puts a large resistor in series with the motor, in 2nd a smaller and in 3rd no resistor, so full battery power to the motor.
I know it is not very energy efficient but i just want to go easy on the new brushes, that's why as a test i wired this dinosaur. It's best described as an high amp potmeter, with copper brushes that move accross copper bars to change between the resistors.
In first position, quad doesn't move, second position it moves slowly (like i run the motor on a 12v battery) but in 3rd (so full power) it takes off real nice, even better than before but this is because there are new brushes in the motor, has nothing to do with the 'controller'.
So this ancient system works but the brushes in the potmeter spark really badly, so they won't last very long. Motor brushes hold up fine for the moment.
Conclusion : nice test but not usable in definitive setup.
 

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#28 ·
Managed to build a battery rack that holds 2 100ah 12v gel batteries. It's a very thight fit as you can see on the pictures. The quad is slowly becoming an EV.
I also modified the transmission, used a motorcycle transmission with 14/42 ratio, chain wheels and chain are a lot heavier than the original ones i used before. Acceleration is really great with this ratio, in the dirt rear wheels spin nicely on take off, real nice to fool around with :).
Still running on 24v for the moment, with the better transmission i think it's time to upgrade.
I ordered this motor http://www.evdrives.com/mars_motor_me0708_etek-r.html with matching controller to run the quad on 48V.
One of the next things to do is to get the tacho up and running, i don't know why yet but although i'm using the original wiring the thing doesn't work. It would be nice to know my speed and distance of travel ... if anybody has any idea's you can always let me know. I tried it with the motor lying next to it, all wires connected and motor grounded to the chassis with jumper cables but still nothing. It's a nice lcd tacho with build in battery monitor for the auxiliary battery.
Signal lights for headlight, direction lights etc work, but that's it, very strange.
 

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