No clutch , so no grass cutting or snow blowing in this setup. We'll see with the tiller but have my doubts on 200A continuous...
444 EV Conversion
A little background;
After moving from the city to a small acreage, we started looking for a small garden tractor. In 2019 a Case 448 with mower, tiller and snow thrower attachments came up for sale. Without knowing anything about these tractors we purchased and basically that was it, I was hooked.
Since then, we picked up two more Case tractors both 444 models. The 448 is still our main tractor, the Onan 18hp runs so smooth and other than regular maintenance it’s been problem free, fantastic machine. As for the 444 tractors, both were older units (pre 1976) in working order but not quite in the same running condition as the 448 but still great machines.
At this point I decided to combine my passion for these tractors with my interest in electric vehicles…It seemed a natural fit with the hydraulic drive of the Case design and simply replacing the internal combustion engine with an electric motor. However, there were a few other considerations not initially apparent…Anyway this is how it went down (and apology for lack of pics and detail throughout the process):
The Case 448 (pride and joy):
![Tire Wheel Automotive tire Vehicle Motor vehicle]()
The Case 444 (to be converted to EV, the other for parts as required):
![Wheel Tire Plant Automotive tire Vehicle]()
Step 1 – Tear down and clean:
![Chainsaw Wood Road surface Asphalt Tree]()
![Road surface Asphalt Wood Automotive tire Public space]()
Step 2 – Painting of individual parts. For this I used (thank you so much from others in this forum) Dupli-Color Chevrolet Orange-Red DE1607. For the complimentary color I went with black rather than the “desert sunset” mostly due to availability (I get this isn’t everyone’s cup of tea). However, the fact I’m kinda butchering the original design by removing the combustion engine anyway, what’s one more change…
![Shelf Wood Tire Shelving Motor vehicle]()
Step 3 – Rebuild:
Note at this point I decided to replace the rear tires with: BKT model: TR144 and the front tires with Carlisle Super Lug model: 5100969:
![Tire Plant Wheel Automotive tire Vehicle]()
![Plant Wheel Tire Vehicle Tractor]()
![Plant Tire Wheel Tractor Vehicle]()
Step 4 – Now for the electric motor:
This system is designed around 48V only because I already had some batteries around from another project. Designed using a LiFePo4 battery bank for longevity reasons (they just handle way more charge cycles than other battery materials). The bank is 48VDC, 51Ah (but expandable). The motor is 10kW which should equate to the original 14hp Kohler combustion engine:
![Automotive tire Motor vehicle Electrical wiring Engineering Automotive design]()
Next step coming soon…I'm just finishing up the motor mount to couple with the pump, battery box, and working on the electric harness at the moment.
<UPDATE>
Got a first coat of paint on the hood, decals on the way:
![Wood Water bottle Gas Rectangle Composite material]()
Winter has really set in around here and without an adequate heated space to work on the tractor I’m looking into the battery box / on board charging portion.
So for the battery storage I figured take advantage of the fact that it’s going to be heavy (regardless how many batteries I end up with). My goal here is to be able to attach the battery box to the rear sleeve hitch when using the front blade in winter and attach to the front end of the tractor when using the tiller in summer. As a starting point I found a commercial box designed for dual 8D batteries. Not the type I’m using but the dimensions seemed to work out nice (bonus that it has slots to run the cables):
![Rectangle Automotive exterior Wood Bumper Gas]()
Next I’ll look at making a heavy duty housing for this box that mates with both ends of the tractor.
My tractor wiring harness will have connectors at both the front and the back so the battery box can be easily connected in both configurations. Earlier I mentioned the system was designed using 48V only because I already had couple of these batteries. These lithium iron phosphate batteries have built in electronics where I’m not comfortable connecting them in series to increase the voltage, not to mention it would add complexity to the charging process. I don’t have an issue with connecting in parallel to increase Amp hours. Having said that, given the choice I’d have gone with a 72V, or ideally 96V setup. The issue with lower voltage is the massive current draw (couple hundred amps), I’m using 1/0 AWG between the battery box and the motor controller with some very large connectors. I guess the flip side is cost, it seems to me the higher the system voltage you pay more for components…
When it comes to charging this beast, I didn’t want to be pulling out the individual batteries to charge. I also didn’t want the hassle of connecting a charger all the time. The plan is to have an on-board charger. I haven’t selected the charger yet and will have to wait until I determine the Ah rating of the battery bank. I did however install the power entry so a regular extension cord will power the charger:
![Automotive tire Motor vehicle Bumper Automotive design Red]()
Note both the battery box and power entry I found at NOCO
<UPDATE>
Wanted to add an electric fan, picked up a 6.6"x 6" (2" depth), 48VDC, 17W with decent CFM. I mounted it with vibration dampers and hoping it doesn't make too much noise...Planning to control it on / off based on hydraulic fluid temperature.
![Motor vehicle Red Gas Auto part Machine]()
After moving from the city to a small acreage, we started looking for a small garden tractor. In 2019 a Case 448 with mower, tiller and snow thrower attachments came up for sale. Without knowing anything about these tractors we purchased and basically that was it, I was hooked.
Since then, we picked up two more Case tractors both 444 models. The 448 is still our main tractor, the Onan 18hp runs so smooth and other than regular maintenance it’s been problem free, fantastic machine. As for the 444 tractors, both were older units (pre 1976) in working order but not quite in the same running condition as the 448 but still great machines.
At this point I decided to combine my passion for these tractors with my interest in electric vehicles…It seemed a natural fit with the hydraulic drive of the Case design and simply replacing the internal combustion engine with an electric motor. However, there were a few other considerations not initially apparent…Anyway this is how it went down (and apology for lack of pics and detail throughout the process):
The Case 448 (pride and joy):
The Case 444 (to be converted to EV, the other for parts as required):
Step 1 – Tear down and clean:
Step 2 – Painting of individual parts. For this I used (thank you so much from others in this forum) Dupli-Color Chevrolet Orange-Red DE1607. For the complimentary color I went with black rather than the “desert sunset” mostly due to availability (I get this isn’t everyone’s cup of tea). However, the fact I’m kinda butchering the original design by removing the combustion engine anyway, what’s one more change…
Step 3 – Rebuild:
Note at this point I decided to replace the rear tires with: BKT model: TR144 and the front tires with Carlisle Super Lug model: 5100969:
Step 4 – Now for the electric motor:
This system is designed around 48V only because I already had some batteries around from another project. Designed using a LiFePo4 battery bank for longevity reasons (they just handle way more charge cycles than other battery materials). The bank is 48VDC, 51Ah (but expandable). The motor is 10kW which should equate to the original 14hp Kohler combustion engine:
Next step coming soon…I'm just finishing up the motor mount to couple with the pump, battery box, and working on the electric harness at the moment.
<UPDATE>
Got a first coat of paint on the hood, decals on the way:
Winter has really set in around here and without an adequate heated space to work on the tractor I’m looking into the battery box / on board charging portion.
So for the battery storage I figured take advantage of the fact that it’s going to be heavy (regardless how many batteries I end up with). My goal here is to be able to attach the battery box to the rear sleeve hitch when using the front blade in winter and attach to the front end of the tractor when using the tiller in summer. As a starting point I found a commercial box designed for dual 8D batteries. Not the type I’m using but the dimensions seemed to work out nice (bonus that it has slots to run the cables):
Next I’ll look at making a heavy duty housing for this box that mates with both ends of the tractor.
My tractor wiring harness will have connectors at both the front and the back so the battery box can be easily connected in both configurations. Earlier I mentioned the system was designed using 48V only because I already had couple of these batteries. These lithium iron phosphate batteries have built in electronics where I’m not comfortable connecting them in series to increase the voltage, not to mention it would add complexity to the charging process. I don’t have an issue with connecting in parallel to increase Amp hours. Having said that, given the choice I’d have gone with a 72V, or ideally 96V setup. The issue with lower voltage is the massive current draw (couple hundred amps), I’m using 1/0 AWG between the battery box and the motor controller with some very large connectors. I guess the flip side is cost, it seems to me the higher the system voltage you pay more for components…
When it comes to charging this beast, I didn’t want to be pulling out the individual batteries to charge. I also didn’t want the hassle of connecting a charger all the time. The plan is to have an on-board charger. I haven’t selected the charger yet and will have to wait until I determine the Ah rating of the battery bank. I did however install the power entry so a regular extension cord will power the charger:
Note both the battery box and power entry I found at NOCO
<UPDATE>
Wanted to add an electric fan, picked up a 6.6"x 6" (2" depth), 48VDC, 17W with decent CFM. I mounted it with vibration dampers and hoping it doesn't make too much noise...Planning to control it on / off based on hydraulic fluid temperature.
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61 - 78 of 78 Posts
So i was in a hurry last time i posted, freed up a bit now.. As far as 200a @ 48v, it's fairly easy to get a ballpark idea of power requirements between hp and W, because 746w=1hp.
So for example i have an old JD 112 garden tractor that had 12hp, and it's got a 30" tiller on the back of it. Right there you know it takes less than 12hp to run a 30" tiller under a wide range of conditions or they wouldn't sell it that way. It would depend on ground conditions, depth, and travel speed how much hp was actually required. But let's say it took 6hp to run the tiller. 6 x 746 = ~4500w. Now, 4500w divided by 48v would equal Amps required to do it (but let's use 50v because that's more realistic for a "48v" lifepo4 pack, and easier math). 4500w / 50v = 90amps. But, nothing is 100% efficient, so if we say that all the junk between the battery and the tiller adds maybe 20%, 90 X 1.2 = 108amps. So if you assume 6hp to run a 30" tiller, with a 48v nominal battery pack and 20% efficiency losses, you would need 108 amps to do that. Now, take your 51ah battery, and divide by amps to get hours. 51ah / 108a = .47h. So about half an hour of tilling like that to drain from full to empty.
That doesn't consider the power used to push the tractor, but considering the speeds involved you could be pedaling the tractor with your own legs and it wouldn't kill you. The power to propel the tractor at tilling speeds would probably add only 5% to that power consumption.
So that's an example of how to ballpark power, amps required, and how long it will last. Not exact, but good enough to plan a project around.
Now, issues.. i think the Case tillers are bigger. You have electric conversion losses AND hydraulic conversion losses. And probably biggest issue is just the size of the battery, not in terms of run time but in terms of something called C rate. Batteries have certain rates of charge and discharge they are comfortable with, and beyond that bad things start happening. On an old lead acid battery you get a lot of heat buildup, bubbling electrolyte creating flammable gases, etc. On a Lifepo4 you're mostly just shortening it's lifespan but not making it dangerous, so that's nice.. Lifepo4 im pretty sure have max recommended current of about .5c, which means you preferably shouldn't fully charge or discharge it any faster than 2 hours. So the above scenario would be highly abusive to the battery as it would be closer to 2c.
![Font Screenshot Number Circle Parallel]()
You can get the C rate from the amp hours. 51ah means 51amps flowing out of it represents 1c, because it would take 51amps for 1 hour to get 51ah, that's 1C. Trying to flow ~25amps out of it would be .5c (it should be happy). 25amps x 50v= 1250w / 746 = 1.6hp continuous. That battery is only happy providing ~1.6hp continuously, any faster and you're burning the candle from both ends and shortening its lifespan.
I understand it's a 'proof of concept' battery and more capacity will be installed later. This is just an example of how it's not just how long the battery can do something once, but whether it's healthy for the battery to be doing that repeatedly.
And with the old GE electraks my impression is that while they could perform for longish periods, they were killing the batteries by doing so. This is the same truth as the current lead acid 48v zero turn mowers which CAN mow 1 or 2 acres or whatever they claim, but you're beating the batteries to death and by next year it'll be a fraction of that because you're murdering the batteries. If you stay in their 'long term healthy' rate-of-discharge and depth-of-discharge limits, they can probably mow .5 acres or less and be able to expect to do that for several years, more like we would expect a set of properly maintained golf cart batteries or a car battery to last. But that number doesn't sell mowers OR batteries.
Saying it can mow 1 or 2 acres gets the mowers out the door, and what happens next year is that guy's problem. But we do sell replacement batteries so you can mow 2 acres again. 🤑
So for example i have an old JD 112 garden tractor that had 12hp, and it's got a 30" tiller on the back of it. Right there you know it takes less than 12hp to run a 30" tiller under a wide range of conditions or they wouldn't sell it that way. It would depend on ground conditions, depth, and travel speed how much hp was actually required. But let's say it took 6hp to run the tiller. 6 x 746 = ~4500w. Now, 4500w divided by 48v would equal Amps required to do it (but let's use 50v because that's more realistic for a "48v" lifepo4 pack, and easier math). 4500w / 50v = 90amps. But, nothing is 100% efficient, so if we say that all the junk between the battery and the tiller adds maybe 20%, 90 X 1.2 = 108amps. So if you assume 6hp to run a 30" tiller, with a 48v nominal battery pack and 20% efficiency losses, you would need 108 amps to do that. Now, take your 51ah battery, and divide by amps to get hours. 51ah / 108a = .47h. So about half an hour of tilling like that to drain from full to empty.
That doesn't consider the power used to push the tractor, but considering the speeds involved you could be pedaling the tractor with your own legs and it wouldn't kill you. The power to propel the tractor at tilling speeds would probably add only 5% to that power consumption.
So that's an example of how to ballpark power, amps required, and how long it will last. Not exact, but good enough to plan a project around.
Now, issues.. i think the Case tillers are bigger. You have electric conversion losses AND hydraulic conversion losses. And probably biggest issue is just the size of the battery, not in terms of run time but in terms of something called C rate. Batteries have certain rates of charge and discharge they are comfortable with, and beyond that bad things start happening. On an old lead acid battery you get a lot of heat buildup, bubbling electrolyte creating flammable gases, etc. On a Lifepo4 you're mostly just shortening it's lifespan but not making it dangerous, so that's nice.. Lifepo4 im pretty sure have max recommended current of about .5c, which means you preferably shouldn't fully charge or discharge it any faster than 2 hours. So the above scenario would be highly abusive to the battery as it would be closer to 2c.
You can get the C rate from the amp hours. 51ah means 51amps flowing out of it represents 1c, because it would take 51amps for 1 hour to get 51ah, that's 1C. Trying to flow ~25amps out of it would be .5c (it should be happy). 25amps x 50v= 1250w / 746 = 1.6hp continuous. That battery is only happy providing ~1.6hp continuously, any faster and you're burning the candle from both ends and shortening its lifespan.
I understand it's a 'proof of concept' battery and more capacity will be installed later. This is just an example of how it's not just how long the battery can do something once, but whether it's healthy for the battery to be doing that repeatedly.
And with the old GE electraks my impression is that while they could perform for longish periods, they were killing the batteries by doing so. This is the same truth as the current lead acid 48v zero turn mowers which CAN mow 1 or 2 acres or whatever they claim, but you're beating the batteries to death and by next year it'll be a fraction of that because you're murdering the batteries. If you stay in their 'long term healthy' rate-of-discharge and depth-of-discharge limits, they can probably mow .5 acres or less and be able to expect to do that for several years, more like we would expect a set of properly maintained golf cart batteries or a car battery to last. But that number doesn't sell mowers OR batteries.
Saying it can mow 1 or 2 acres gets the mowers out the door, and what happens next year is that guy's problem. But we do sell replacement batteries so you can mow 2 acres again. 🤑
For the motor mounting this bracket is 10ga galvanized steel and bolts to the existing Case engine mounts. Seems to fit quite nice:
![Gas Composite material Machine Engineering Auto part]()
![Gas Machine Engineering Motor vehicle Metal]()
The panel containing the motor controller mounts on the side, this is the one I made earlier with the piano hinge that can be folded down for access to the wiring:
![Shelf Wood Engineering Gas Machine]()
The panel containing the motor controller mounts on the side, this is the one I made earlier with the piano hinge that can be folded down for access to the wiring:
That looks fantastic. Can't wait to see the next update.
I'm currently in a training seminar for how to assemble a Switch Labs EV kit car.
I'm currently in a training seminar for how to assemble a Switch Labs EV kit car.
Still waiting on the hydraulic pump mounting plate but thought I’d share a couple more pictures. My plan of the piano hinge motor controller panel didn’t work out (oh, how I tried),
this panel is now fixed:
![Gas Engineering Machine Composite material Motor vehicle]()
![Motor vehicle Gas Engineering Machine Auto part]()
I also decided to make all the major connection points in the former home of the gas tank as inevitably I'll need to make wiring changes and this seemed to be the most accessible location:
![Tire Wheel Vehicle Automotive tire Hood]()
this panel is now fixed:
I also decided to make all the major connection points in the former home of the gas tank as inevitably I'll need to make wiring changes and this seemed to be the most accessible location:
So the pump / motor adapter turned out to be quite the project…
I started by getting a 3/4 “aluminum disc made up:
![Wood Art Composite material Circle Oval]()
Drilled and counterbored some drive-in studs on the pump side:
![Rim Composite material Bicycle part Auto part Circle]()
![Wood Composite material Auto part Rim Circle]()
With the motor side, I drilled and counterbored 6x M8 screw caps:
![Wood Gas String instrument Audio equipment Musical instrument]()
Picked up some black lug nuts to finish it off:
![Automotive design Gas Motor vehicle Engineering Machine]()
I started by getting a 3/4 “aluminum disc made up:
Drilled and counterbored some drive-in studs on the pump side:
With the motor side, I drilled and counterbored 6x M8 screw caps:
Picked up some black lug nuts to finish it off:
61 - 78 of 78 Posts
