EcoRider - riding mower electric conversion
 

Well, the time has come for my first EV project! I really wanted to convert the Toyota Paseo I picked up a while ago, but it would have cost too much for me at the moment. So, my next thought was that I really could use a riding mower. I have push mowed my lawn, and it takes a long time. So, I talked things over with Ben Nelson and MetroMPG, the two EV guys I know and decided to go with an electric riding mower.

This weekend I picked up a Simplicity 728 (no idea what year) from a very kind gentleman. I found and got the mower for free using FreeCycle.org. It currently has a mildly used 8hp Briggs engine in it. The deal with the donator was that I take the engine out and return it to him since it hasn't seen much use. I was all too happy to oblige! So, now I have a new project for this winter. Hopefully updates will come fast. :)

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Sweet Will be watching how you progress!!!

Heh... cool :)

Considering you'll be replacing an 8hp motor instead of a 100hp motor, i expect this would be pretty smooth. Have you set out any "project requirements" (it has to cut my whole lawn without crapping out) or "project specifications" (it must travel xMPH with rotor spinning at yRPM for z Minutes)?

I really don't have any requirements yet besides collecting more parts. I belive the specs I'm planning for will allow for me to cut my lawn without recharging. Other than that, I'm not worried about speed or anything else.

Well, I took the mower out for a spin last night. I really needed to cut the grass and chew up the leaves. So, the mower got its last run on gasoline. It worked quite well for what I seemed to think of as a small mower (only 8 hp).

I'm now starting to track down the necessary other items for the conversion. Ben Nelson said he would donate a few things so I'm really psyched about that! There will be many pictures to come. :)

You can do a lot of things with just 8 hp. I hope the conversion goes well and am looking forward to see lots od pics!

Hey!

I just remembered there's a left-over controller from the forklift: it's a GE EV-1 (not the car) SCR controller. I understand they're less efficient than PWM, and potentially harder on the batteries, which is why we didn't use it in the car.

But others do - you can probably find a dozen cars & trucks on the EV Album using the same one. If I were you, I'd also seriously consider a simple, 100% efficient, 2-speed 24/48v contactor controller. (Or 3 speed with a fat resistor step: 24v+resistor/24v/48v. You don't really need infinite speed control on a lawn tractor.

But you can have the EV-1 for shipping cost, if you want it.

I think I have enough left over cables to build several mock Electraks.

Tim, if you can make it out on Sunday, I can introduce you to my motor collection.

Motor, cables, controller, and batteries are going to be the main things. I have a few contactors kicking around too.


Wait a minute, is this two electric Metro projects giving birth to a little electric riding lawn mower? How cute!


I mean. Eww.

Haha! I LOLed. Thanks.

I also have the forklift's orange strobe light, and... backup beeper. Not sure how useful you'd find those things, but add 'em to the pile if you want.

I'd offer the left over Baker contactors too, but I want to hang onto them for the ForkenSwift's controller bypass/60v turbo idea.

Hee heee.

I also have the strobe light and backup beeper.

That's it we are taking over Tim's project and pimping it out!

Next up: spinner hub caps!

"you might be an ecomodder if......."

Ben- that was hilarious!

Daox- will you be posting build info in this thread or also on ecorenovator?

I'll be posting major updates on both sites.

BTW, did you guys notice that its already aeromodded? Take a look at the rear wheel covers. ;) She's built for speeeeed! (or not)

first thing that comes to mind to me in the design is that v-belts rob energy, do as much as you can with direct drive, we have a spare blade motor for our electrac tractor, it's about the size of a tape reel motor from the old reel to reel tapes on computers from the 60's-70's, an E-tec motor might also work well for the blade drive, the wheel drive motor is going to need to be larger then you might think, as you are going to haul around alot of weight, so a 2-3hp motor might be needed.

Old Simplicity yard tractors ROCK!
(I inherited my grandmothers, I think it is about the same age I am.)

Those rear moon caps are nice!

I have three "spare" motors around right now. I think one would work great for the drive, and another might be good for the blades, or it might be a little too big.

I believe the Electrak has a motor for each individual blade. In this case, a single motor runnning a belt for all three blades, and another motor for just running the wheels might be best.

Cool project, Daox.

Not surprisingly, I like the colour of your tractor.

There are a few conversions on the elec trac owners club forum. maybe I will see you there. Elec-Trak.com

Good luck with it.

Yeah I was already there and have posted.

Thankfully, at the EV association meet I went to yesterday I was able to talk to an elec-trak owner and got some really good info.

It finally got tropically warm (35 degrees) this weekend, and with my insulation project behind me I took some time to do some work on the EcoRider. The first step? Rip out the engine! The previous owner is still patiently waiting for me to return it thankfully.

I also got a chance to talk with an elec-trak owner at an EV meet. He said the Elec-traks can do about 2 acres of mowing before they need to be recharged. So, with my less than an acre to mow, I'm not going to worry at all about not having enough battery capacity.

Now pics!


Pulled the top cover off.
http://ecorenovator.org/pictures/ecorider007.JPG


Front cover off.
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Yay, the happy moment of draining the last bit of gas this mower will ever see.
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Engine GONE!
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I see that all the work on Tom's Neon have motivated you to work on your own EV! :thumbup:

I noticed that it's an 8-horse Briggs you are pulling out of there. The Etek motor is rated at 8hp and it also a Briggs&Stratton.

Also, you have a CM400 and you haven't converted it to electric!!?!? Come on, you know you want to!!!

PS - I also have a Simplicity tractor - check out my snowblower attachment next time you are over. It might fit the EcoRider.

Cool project. Keep us posted on it.

PS I really like my 24 volt electric push mower. Never runs out of gas, doesn't stink, no problems starting it, don't need ear protection to run it either, turns on and off with the push of a button. Never realized how annoying gas ones were till I got this one (its cordless btw)

Yeah, I got home from the EV build day and decided it was just way too nice out to stay inside. So, I went out and started working on my grandmother's Ford Taurus that needs new hard brake lines. I got as far as I could on that without having to make a parts run and it was still too nice to go inside. I eyed up the EcoRider, grabbed my ratchet, and started going to town.

Speaking of the Etek, I was talking to Tom about what motor to use (mentioning that you offered yours) and the possibility of not using a controller on it and how that all works. He said it would be fine as long as I didn't overvolt the motor too much. So, I'm curious as to what kind of voltage the extra motors you have laying around are? What are their rated specs? He said something with 2-4 hp would be fine.

Great Idea! I have been looking for motors to build an electric mower also. There are a lot of motor to check out, some have high voltage 90 to 200. What kind of rpm are you looking for.

Thanks Itse..

I promised Daox that I would bring my best forklift motors with next time I see him.

Hopefully, we can get some suggestions from the other EV club guys on which one might work the best.

From what I've read, which isn't a TON, the target RPM should be anywhere from 1700 to 3400 rpm. However, in my case I can simply use a different size pulley if the motor is too slow which will likely be the case (vs it being too fast).

Old walkie/rider trucks were built using contactors only.Old Barret, Big Joe ect. have 12v to 36v motors, the contactors, possible sufficiant wiring and the control devices necessary for a lawn tractor. They will use more power at low speeds than electronically controlled units, though. The curtis contolled trucks have been around since the mid to late 80s so a cheap set up should be available also. The problem with a lawn tractor is battery storage and the sheer weight of it all on soft ground and slippery grass. Extra wide turf tires might be wise to reduce depressions in the soil and traction issues with upgrade mowing. The center of gravity will need to be low enough to avert tipping on hilly terrain. With a large flat lawn, a power trailer would solve all the issues including range.

Well, I just hit the jackpot last night. Tom G, the owner of the 300V Neon in progress that we've been working on just donated a ton of parts for the project. Almost everything I'll need.

I've also decided to move this project over to EcoRenovator's Forum. All further updates will be over there.

I got another good update. I took apart the motor last night and think I've figured out where everything is going to go.

EcoRider - riding mower electric conversion - EcoRenovator

Another update. I got the motor face drilled and tapped and found some pullies for the motor.

EcoRider - riding mower electric conversion - EcoRenovator

On Craiglist Jacksonville, fl I picked up a 24v Electric Mower that the guy said was under powered and didn't charge right, took it home and it charged right up. I mowed and loved it. Great deal for $100. Tomorrow I am going to check out a Golf Cart also $100, it is missing a switch but does have the electric mower. I also hope to build and Electric Rider.

Big update here. I just got back from the first ride on the ecorider! It was a blast.

Check it out here:

EcoRider - riding mower electric conversion - Page 5 - EcoRenovator

More updates. I'm rebuilding the deck to hopefully lower the amperage draw it takes to spin the blades up.

EcoRider - riding mower electric conversion - Page 7 - EcoRenovator

Test number two went went off last night. I lowered the voltage and only used two batteries instead of three. Oddly enough, my amperage was lower than with three batteries (which is opposite of what it should have been). My guess is that the lower motor rpm really helped out. At 36 volts (3 batteries) the motor spins 1.5 times as fast as 24 volts (2 batteries) since rpm is proportional to voltage. At 24 volts, my motor rpm is much more in line with what was intended for the mower. The result was driving around still took 20-25A, but the mowing deck only took another 25A! This is HALF the amperage of the last test. It seems that the deck rebuild and proper pulley sizing really works out well. I am very excited about this!

The next step is to procure some actual deep cycle batteries. My power died off insanely fast because I just used two semi-dead staring batteries. One trip around the house and they were already puking on me. The local battery store has some group 24 deep cycles for $70 which seems pretty reasonable. I'll have to look into what else they have too. I might want to go with something larger. I'd ideally like a 1 hr run time. At 50A, I would get about 40 minutes of run time since you don't want to cycle batteries beyond 50% to retain good life. The alternative is to go back to 36 volts, but resize my pulleys. This theoretically would drop my amperage down to ~33A. This would (again theoretically) give me right around an hour of run time and maybe a bit more because of the peukert effect. So, 36 volts is looking like the way to go.

golf cart batteries
 

Group 24, aka golf cart batteries, should be perfect for this application. I'm not totally convinced that $70 is a fantastic price. Call a golf cart place just for comparison.

Good progress.

Please carry on.

troy

Well, I re-ran my numbers and it looks like I need at least a 190Ah battery if I am going to be able to mow for an hour straight without recharging. I got some tips from the local EV guys that helped out here. My estimates were quite optimistic. So, I think I will be looking at going to use 8Vs or 6Vs so I can get some more Ahs.

Have fun making your lawn mower electric powered. Sounds pretty ambitious. I guess if a golf cart can do, why not a lawn mower?

Its up and running with batteries from Ben Nelson. I got a video over on ecorenovator.

EcoRider - riding lawn mower electric conversion - Page 10 - EcoRenovator

I got my batteries back from you and heard a rumor you got some new ones!

Where's the update!? You gotta let us know!

I did get new ones! They just came in on Friday and I just picked them up yesterday morning actually. I'll post updates when I have actually done some work.

I ended up going with an AGM 150Ah group 31 battery. They were surprisingly well priced at $93. I bought them from a fork lift repair shop up in Cedarburg which is just a few miles north of me.

They should give me enough run time to do at least half the lawn at once with charge to spare. I decided against going all out and trying for the 1hr run time simply because I never once cut the entire lawn at one time this year. The field is always dry and I end up mowing it once ever three or so times I mow around the house.

Looks like its time for the monthly update of this thread. :) For those who would like to catch up quickly, I have actually written a blog series that sums it up fairly quickly.

EcoRider blog series

More in depth info is available in the build thread on ecorenovator. Or, you can ask questions here.

I also recently made an evalbum page for the mower too.



Okay, on to the updates! :)

At the end of last month I picked up the batteries that I'll be using on the mower. They are group 31, 150Ah flooded batteries. I picked them up from a local fork lift repair place. They did blow the budget for the project kinda as they are new. But, with the life I expect out of them, I'm not going to worry about it. I couldn't find any good sources for used batteries at the time.

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Last weekend I started the battery racks. I went with two in the back for traction, but one in the front to keep some reasonable distribution of weight (no wheelies!). The rear rack is all done, but the front one still needs to be made. I like how the rear rack will give me very easy access to the batteries for checking the water level. The one up front won't be quite as easy to check since it'll be under the hood.

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I'm really looking to get this thing running soon as I need to cut the grass before the snow starts to stick. My in laws recently took back the push mower we had borrowed from them so I have no way of mowing right now.

However, I'm also a bit excited to see the snow fly so I can get a chance to try out this attachment I got a few weeks back. :)

http://ecorenovator.org/pictures/ecorider056.JPG

Tim,

I think I may actually have THE EXACT SAME snowblower attachment.
We should do an EV SnowBlower work-day sometime.

It might be possible to pull the drive pulley off the blower and mount a direct-drive motor directly in it's place. We would have to see how many amps that pulls for if it is practical or not!