joe.monahan
1 mW
Barn find. Hoping to convert to electric but learning as I go. Anyone with any input and Ill update as I go, even if it is a disaster.
Honda ATV 4-wheel drive conversion
- Thread starter joe.monahan
- Start date
If you define the job (speed, acceleration), it has to do for you, and the conditions (terrain, wind, surface, weight) it has to do it under, and how long / far it has to do the job (range) then you can use simulators / calculators like the ebikes.ca motor and trip simulators to guesstimate how much power it will take to do it, and how much capacity to get the range you need.
There are also some other offroad EV projects around, and some quads of various types, that may help, too.
There are also some other offroad EV projects around, and some quads of various types, that may help, too.
joe.monahan
1 mW
I would love to do it all - build the batteries, etc but I think I have enough on my plate just to figure out how to get the existing engine out! The bike calculators are limited a bit because they dont account for the weight, 4 big tires on the ground and the wind catching profile. But unsurprisingly they point to a big motor and a big battery. I wondered if I could use the EGO batteries (or their knock-offs) in a chain to power a 3K motor. They are 56V and range from 2 to 5 Ah. If I could get 6 of them together - like they do for their riding lawnmowers - and a controller that provided maybe 80V and 30Ahs, if that would be enough for what I need.
If they're 5Ah, and 56v (is that full charge, or average voltage?), then six of them in parallel would give you 30Ah, but you'd still only have 56v.
There's no way to get 80v out of them, without disassembling them and building a new pack with a different series cell configuration.
I dont' know what currents they're capable of, but it's probably more than 2C, so you could probably supply at least 60A with a 6p pack setup of those 56v units. That gives more than 3kw capability at 56v.
Whether or not 3kw will do what you want, you'd have to either test, or simulate, or calculate.
The ebikes.ca motor simulator has custom fields for almost everything, so for instance if you know the rolling resistance of your tires, you can add them up to simulate that in two wheels, you can guess or test the Cd/etc for wind resistance, and you can enter the total weight you expect, etc. (you can also setup custom motors and controllers, as well as gearing for non-hubmotors)
There's no way to get 80v out of them, without disassembling them and building a new pack with a different series cell configuration.
I dont' know what currents they're capable of, but it's probably more than 2C, so you could probably supply at least 60A with a 6p pack setup of those 56v units. That gives more than 3kw capability at 56v.
Whether or not 3kw will do what you want, you'd have to either test, or simulate, or calculate.
The ebikes.ca motor simulator has custom fields for almost everything, so for instance if you know the rolling resistance of your tires, you can add them up to simulate that in two wheels, you can guess or test the Cd/etc for wind resistance, and you can enter the total weight you expect, etc. (you can also setup custom motors and controllers, as well as gearing for non-hubmotors)
From-A-To-B
100 W
The two Ego batteries I’ve opened up had Samsung 25R cells inside — so plenty capable cells.
But it would strike me that learning how to build a battery from used EV modules or paying someone for their help in this regard may actually be the easier route when compared to running an ATV off of a half a dozen lawn mower batteries.
joe.monahan
1 mW
Baby steps I suppose, but I was happy to just get all the engine parts out and the 2 differentials separated. Its going to be interesting to see if/how to get the motors connected to the drive shafts> The examples Ive seen tend to be chain drive, which I think would be easier.
I wondered if it would be possible to use two motors and two batteries, or one battery connected to two motors, one for the front wheels and one for the rear wheels?
joe.monahan
1 mW
If they're 5Ah, and 56v (is that full charge, or average voltage?), then six of them in parallel would give you 30Ah, but you'd still only have 56v.
There's no way to get 80v out of them, without disassembling them and building a new pack with a different series cell configuration.
I dont' know what currents they're capable of, but it's probably more than 2C, so you could probably supply at least 60A with a 6p pack setup of those 56v units. That gives more than 3kw capability at 56v.
Whether or not 3kw will do what you want, you'd have to either test, or simulate, or calculate.
The ebikes.ca motor simulator has custom fields for almost everything, so for instance if you know the rolling resistance of your tires, you can add them up to simulate that in two wheels, you can guess or test the Cd/etc for wind resistance, and you can enter the total weight you expect, etc. (you can also setup custom motors and controllers, as well as gearing for non-hubmotors)
Thank you for that. I noticed there are battery connectors on bikes.ca site that allow two 36V batteries to be connected in a series to produce 72Vs. Maybe an EGO battery adapter could be built or modified to connect 2 or 3 in series and the rest in parallel?
I dont understand current at all, so more googling for me today
joe.monahan
1 mW
Thanks. By used EV modules you mean from a wrecked LEAF or similar? Can they be taken apart and reconfigured you mean?
Or keep an eye on sites like batteryhookup to see if they sell off already broken down cells for reuse.
I haven't done and ATV before, but I'm pretty sure you should be thinking about 1 large/capable motor for the rear differential, and leave the front wheels alone for just steering.
Unless your use case is going to involve a ton of off-roading where AWD is necessary? Then an argument can be made for sending power to the front wheels as well. You haven't mentioned what kind of action the finished ATV is expected to see.
Google Dunning-Kruger effect while you are at it.I dont understand current at all, so more googling for me today
How easy this is depends on the battery and BMS design in them.
If you connect batteries in series that have a BMS, then the BMS must be designed to handle the total pack voltage (not just that of the individual batteries), which is not common. If it isn't, then when it shuts off for any protection function, it now has the whole pack voltage across it, which can damage or destroy the FETs trying to keep the pack shut off--which either makes the pack nonfunctional by permanently disconnecting it from the outside world, or by causing the FETs to fail stuck on, and preventing it from being able to disconnect itself ever, regardless of what happens inside the pack.
You can install "bypass" diodes that essentially short around the pack if the BMS shuts off that should work around this issue; there are posts (more than a few by Fechter) about this in various "seriesing battery pack" threads.
joe.monahan
1 mW
I was contacted by a company in Viet Nam about these wheels as a possible solution. I wonder if they are an easier option than trying to connect the electric motor shaft to the existing drive shaft? I could maybe get rid of the differentials all together with these hub motors and have a simpler solution....
Looks like they design things, but I don't see anywhere to buy anything they have designed. I really like the spec for Moment of Inertia = BIG. 
Ask them to point you to the store you can buy them at, where you can see photos of them installed on various real vehicles driving around.
But you could certainly replace all the wheels with hubmotors, there are plenty of motors around with single-ended axles or other mounting solutions. QSmotors has several on their site (or see their sale thread in that part of the forum, and Goldenmotor also makes some, as do other companies (UUmotor? can't recall the names for sure).
Disadvantage is you can't change the gearingg, you're stuck with the speed/torque you start with, and if it's not enough you have to change the controller and battery for a higher voltage if you need more, and if the motor can't do it you ahve to change all the wheels. You also get much heavier wheels so your suspension doesn't work like it did before, is less responsive, etc.
A central motor (or set of them) means just changing the gearing between motor and wheels to change the speed or torque, or if it's not enouggh motor you change the motor, etc. Structure of vehcile doesn't changge, or suspensin behavior, etc.
Ask them to point you to the store you can buy them at, where you can see photos of them installed on various real vehicles driving around.
But you could certainly replace all the wheels with hubmotors, there are plenty of motors around with single-ended axles or other mounting solutions. QSmotors has several on their site (or see their sale thread in that part of the forum, and Goldenmotor also makes some, as do other companies (UUmotor? can't recall the names for sure).
Disadvantage is you can't change the gearingg, you're stuck with the speed/torque you start with, and if it's not enough you have to change the controller and battery for a higher voltage if you need more, and if the motor can't do it you ahve to change all the wheels. You also get much heavier wheels so your suspension doesn't work like it did before, is less responsive, etc.
A central motor (or set of them) means just changing the gearing between motor and wheels to change the speed or torque, or if it's not enouggh motor you change the motor, etc. Structure of vehcile doesn't changge, or suspensin behavior, etc.
joe.monahan
1 mW
Im afraid my lack of experience is showing. Looking at the inside of the front and rear wheels I cant tell where or how the hub motors would mount? I see what looks to be brakes on both sets of wheel. Would the motors just screw on to the lugs where the existing wheels are now, and all else remain the same? In other words, would the hub motors just replace the existing wheels?
I see some of the hub motors have "single axels" but I dont think that option would work here. I have emailed QS-Motors but have not heard back yet. I dont see any hub motors on Golden Motors but I emailed them anyway. Im checking UU mOtors now. But I think I need some install videos!
Thank you for your help with this!
Joe
Attachments
for this type of mounting usually they replace teh whole wheel mount / drum, and the wheel hubs then bolt to the motors just like they used to the original mounts. that way you don't ahve to pull hte motor off to change the tire, just the wheel like normal.
because every vehcile is different you mayhave to design and make adapter parts to connect the motor assembly to the steering and/or suspsension mounts. the motor makers generally can't supply those as there are too many possible designes.
you should rpobably check with qsmotors about a central motor drive that would mate with your transmissin/transaxle/wahtever it is.
depending on the input shaft design ou might have to make an adapter plate that includes bearings, or just a splined connector between motor shaft and input shaft.
if you look at some of the various car conversions on diyelectriccar forums especially from several years to a decade ago, there are a lot of them that use big old forklift motors with splined shafts that have to be adapted this way, so you can see how things might connect up. some of the ev conversion companies out there make kits for this for scertain types of motors and cars / etc that are commonly converted, that may also show you how they do it.
ther'es a motorcycle conversion here on es somewhere from severla years ago where the guy actually sat down with a lot of patience and hand filed a splined shaft adapter, i think to mount a motor so it would run his shaft-drive motorcycle.
depending on the input shaft design ou might have to make an adapter plate that includes bearings, or just a splined connector between motor shaft and input shaft.
if you look at some of the various car conversions on diyelectriccar forums especially from several years to a decade ago, there are a lot of them that use big old forklift motors with splined shafts that have to be adapted this way, so you can see how things might connect up. some of the ev conversion companies out there make kits for this for scertain types of motors and cars / etc that are commonly converted, that may also show you how they do it.
ther'es a motorcycle conversion here on es somewhere from severla years ago where the guy actually sat down with a lot of patience and hand filed a splined shaft adapter, i think to mount a motor so it would run his shaft-drive motorcycle.
eee291
100 kW
I think it's wise to steer clear of hub motors, a conversion with hubs is at least twice as expensive. Not to mention all the additional fabrication to get the brakes working again.
joe.monahan
1 mW
I did just that. So good advice!
QS Motors suggested the mid-drive 3k or 4k motor and sent some customer photos of a welding job. I brought those to me local welder / fabricator and he said they could do it - and in a way that allowed the motor and battery to be disconnected and removed / replaced. Cost approx $1000.
I think I'll go that route. Probably with the 4k motor and matching controller.
Suggested battery is 72V 52Ah. Is there a reliable US based place to get the right batteries from? Shipping from China Id imagine is expensive?
Thanks again - much appreciated.
Joe
joe.monahan
1 mW
Thank-you. Im going with the mid-drive as suggested. Thats what I needed to know about hubs - they only seemed simple. Still trying to figure out where a good source for the battery might be. Any suggestions?
Joe
A-DamW
1 kW
Batteryhookup.com
They have good prices, good selection, and I have never seen batteries packed so well for shipping.
Note, I have an affiliate account with them, if you use the link above, you get a 5% discount off your order.
A-DamW
1 kW
A couple of these in series would get you 72v nominal 84v max, already in a case and wired.
Specs claim ~14amps per cell continuous X 11p = ~154amps.
If you needed more power you could get 4 modules and series/parallel them.
If you pushed them hard, 2 modules in series, 72v X 154a = 11,088watts. ~48lbs of batteries, 3.96kWh.
Conservatively, if you had 4 modules, ran them at 200amps max, 72v X 200a = 14,400watts ~96lbs of batteries, 7.92kWh.
110 2170 M50LT 3.6v 5000mah 36v 1.98kWh - $88/kWh
Note, I have an affiliate account with them, if you use the link above, you get a 5% discount off your order.
Specs claim ~14amps per cell continuous X 11p = ~154amps.
If you needed more power you could get 4 modules and series/parallel them.
If you pushed them hard, 2 modules in series, 72v X 154a = 11,088watts. ~48lbs of batteries, 3.96kWh.
Conservatively, if you had 4 modules, ran them at 200amps max, 72v X 200a = 14,400watts ~96lbs of batteries, 7.92kWh.
110 2170 M50LT 3.6v 5000mah 36v 1.98kWh - $88/kWh
Note, I have an affiliate account with them, if you use the link above, you get a 5% discount off your order.
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joe.monahan
1 mW
Thanks for that quick reply. Would these be wired so that I could plug them directly in to my controller? I would rather have a turn-key solution as even installing the battery will be a challenge for me
I feel like 30 miles range would probably be enough, although 40 is probably better.
This is what I see as an option for me:
The motor is for a pretty heavy Honda (formerly 4-WD) ATV. The motor / controller Im considering is
QS Motor:
4000W
72V
80NM torque Max 98NM
Current limit <200A
Controller:
SineWave FOC
Max. Bus Curent 180A
Max Phase Current 660A
Working voltage 48V
Compatible motor: 3000-5000W
I feel like 30 miles range would probably be enough, although 40 is probably better.
This is what I see as an option for me:
The motor is for a pretty heavy Honda (formerly 4-WD) ATV. The motor / controller Im considering is
QS Motor:
4000W
72V
80NM torque Max 98NM
Current limit <200A
Controller:
SineWave FOC
Max. Bus Curent 180A
Max Phase Current 660A
Working voltage 48V
Compatible motor: 3000-5000W
Last edited:
You will be sorely disappointed with your finished product. 100%. You are so deep into this without getting the basics right first.
Your ATV had something like a 30HP gas engine. Your proposed electric drivetrain is not even close.
joe.monahan
1 mW
Nothing that is affordable. If you had a 30HP gas engine and say 4 gallons of gasoline, then to match performance you need roughly a 22kW motor and a battery over 30kWh.
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