# Zero Turn Radius Electric Riding Lawn Mower



## Woodsmith (Jun 5, 2008)

I guess it would be no more complicated then an electric wheel chair. A scrap donor chair may even provide you with a low power starting off point to learn from. 
The cutter deck motor would only need an on off switch/contactor with a sepex or shunt motor.


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## major (Apr 4, 2008)

Woodsmith said:


> I guess it would be no more complicated then an electric wheel chair. A scrap donor chair may even provide you with a low power starting off point to learn from.
> The cutter deck motor would only need an on off switch/contactor with a sepex or shunt motor.


Hey Woody,

How about that sub forum for unusual vehicles, like karts, tractors, mowers, flying saucers, etc. Any progress?

Hey TheRed,

I usually don't like hub motors, but they may actually fit this application, go figure. Unless you live in a real hilly area or have towing requirements, the mower propulsion is relatively low power compared to the blade drive. So independent wheel motors might work, a couple kW apiece. You'll likely have problems finding ones which fit as most are designed for scooters.

But for the blade drive, you'll need a good size motor. That 16hp gas burner was sending most of its power to the blade. You might get by with a 6.6 inch diameter electric motor, but a 7.2 wouldn't hurt.

Kool project.

major


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## TheRedBaron (Jan 31, 2011)

Okay that makes sense! However, my greatest concern would be the independent wheel control. I would like to only have to buy one controller for both hub motors. However, I would have to have different power levels at times to each motor. Are there controllers that can accomplish this?

Oh and I am looking at using a brushless DC hub motors for the wheels. 
An example of such a motor: http://www.hnmotors.de/product_info.php?language=en&products_id=42

Edit: From what I understand, you are not supposed tow with a zero turn radius lawn mower, however...I would like to plan on towing around at least 150-200lbs.


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## Woodsmith (Jun 5, 2008)

major said:


> Hey Woody,
> 
> How about that sub forum for unusual vehicles, like karts, tractors, mowers, flying saucers, etc. Any progress?
> 
> major


We'd need to be looking at maybe a couple hundred threads in it to justify it and someone will have to find all the existing threads to populate it.

Us ordinary admin can't set it up but if we can show good justification then the forum owner can set it up to be populated.


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## Ziggythewiz (May 16, 2010)

I've been wanting to do this for some time. 

I've seen a number of builds that use electric wheelchairs as a starting point, as most of the controls are already there. The cutting blade really doesn't need to be that powerful, I have an electric mower (22") and it pulls around 10 amps (120V AC) so a big blade should only need around 50 amps. I can't imagine using an EV size motor for just the blade, but if you go with an 11" you should be ready for the zombie apocalypse.

Here's a few examples I've come across, I think these all have gas blades, but that'd be the easiest part of the project.

http://members.iinet.net.au/~tnpshow/RCLM/intro.htm

http://rediculouslygoodlooking.com/

http://www.instructables.com/id/Arduino-RC-Lawnmower/


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## TheRedBaron (Jan 31, 2011)

major said:


> Hey Woody,
> 
> How about that sub forum for unusual vehicles, like karts, tractors, mowers, flying saucers, etc. Any progress?
> 
> major


First, an electric flying saucer would rock, but I'm unsure of the power requirements of such a thing. You perhaps would be better off w/ a fusion power plant instead of batteries but who knows?

Anyways, back to a less interesting project (we had wanted to do an electric ultralight but $$ is an issue there, I guess that is like a flying saucer).

The motor I have posted above I want to use as propulsion not for the blades; though hub motors may work for them too, hooked up to a simple switch. With a zero turn lawn mower, each handle would be hooked up to a hub motor and would allow independent operation.

Ziggythewiz, I don't know what your power rating on your blade mower was but I was looking at 1kw motors for the blades.

Also, anyone work with lithium batteries on an application like this or are the lead acids still the primary option here?


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## JRP3 (Mar 7, 2008)

I don't know the actual efficiency losses of the hydrostatic setup but it certainly would be a lot easier and cheaper to use it than multiple motors and controllers. Efficiency losses could possibly be made up by just using an extra battery. Lithium would be neat but probably not cost effective.
Regarding creating another forum for unusual vehicles, I don't think there is enough demand, even though I own one myself. The occasional oddball can hang out here in All Conversions and not feel like an outcast


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## TheRedBaron (Jan 31, 2011)

JRP3 said:


> I don't know the actual efficiency losses of the hydrostatic setup but it certainly would be a lot easier and cheaper to use it than multiple motors and controllers. Efficiency losses could possibly be made up by just using an extra battery. Lithium would be neat but probably not cost effective.


Tried following your link but it appears to be broken . Anyway, the stuff I found on hydrostatics seemed to indicate to me that their inefficiency was sufficiently high (especially something in the lawn mowing range) to really start hampering an electric motor-hydrostatic transmission coupling.

I am also interested in the maintenance issue. With brushless electric motors, there would be few issues in that department. The system would also be more straightforward (battery->controller->motor->wheels) instead of (battery->controller->motor->transmission->wheels). 

Plus transmissions take up space-> space I could use to add more batteries to the mower perhaps?


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## PhantomPholly (Aug 20, 2008)

One good approach to any problem is to put each piece of the puzzle into perspective.

In the first post, the concern raised about using the hydrostatic drive is that it is inefficient.

Let's assume that it is only 50% efficient (Eee gads!). What percentage of your total power consumption does that represent?

Well, if out of 16hp 90% was going to the blades (likely true, if not more - 1.6 hp is an awful lot just to move you around at 4mph!), then 50% of 10% = 5% total power wastage.

Weigh that against the challenges of developing independent reversible controllers for independent wheel motors (now 3 motors).

For the extra weight and complexity of the extra motors and controllers, I think I'd just put on an extra battery.

If it ain't broke, don't fix it!


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## Jimdear2 (Oct 12, 2008)

Red Baron,

In light of the information on powerloss that PhantomPholly just posted and thinking of all of the problems you will see with a designed from scratch system. 

Take a look at this item in Surplus Center. 

https://www.surpluscenter.com/item.asp?item=13-1473&catname=powerTrans

All you need to add are wheels, frame, bateries, controller and a motor. Something that will turn those two pulleys at a constant speed up to 3000 rpm. I would run an independent deck motor, in fact I would have two packs 1 for the deck and 1 for the tractor. 

I built an electric conversion Cub Cadet and am in process of converting one of those tow behind mower decks to electric. 

I really did look at building a zero steer but I just couldn't find a tractor with a blown motor that I could afford back then.

Jim


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## JRP3 (Mar 7, 2008)

TheRedBaron said:


> Tried following your link but it appears to be broken .


Wasn't actually my link, just some automated feature of the forum that creates links for certain terms. Annoying.


> I am also interested in the maintenance issue. With brushless electric motors, there would be few issues in that department. The system would also be more straightforward (battery->controller->motor->wheels) instead of (battery->controller->motor->transmission->wheels).


Actually you'll need two controllers since you'll be sending different signals to each motor when turning if you don't use a transmission. Maintenance on brushed motors would not be a real issue in normal service.


> Plus transmissions take up space-> space I could use to add more batteries to the mower perhaps?


True. You really need to figure out how much run time you need and how much battery it's going to take.


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## jeremyjs (Sep 22, 2010)

If it were me I'd just get a bigger permanent magnet dc or shunt motor and use a contactor to turn it on. I doubt you'd loose much power through the hydrostatic drive simply because you need very little of the power to drive the wheels; unless you're plowing snow with it or something. 

If you go the direct drive route you need a minimum of 2 reverseable drive motors and a controller, throttle, gear reduction drive, etc on each and 1 large blade motor. The cost of that is going to add up fast and then you still have to deal with getting everything calibrated to work well and buy your batteries. If you simply go with 1 larger motor of a type that needs no controller you can put your extra money in the batteries and end up spending a lot less.


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## gor (Nov 25, 2009)

inefficiency?

efficiency of eaton hydraulic and AC55 ev motors:
















i agree with Phantom and JR: all should be put in perspective: 
efficiency of hydraulic drivetrain itself can be high (50hp hydraulic motor you can hold in your hand) - all the matter of fortune spend on design and components: 
homeowner ztr cost $2-3k, industrial -$12-15,000; 
ztr pump -$600; skid-steer pump-$6000 
yes, 28hp lawnmower - engine, 4 wheels, seat, 2 pumps, wheelmotors and blades cost same as small car... : )))) and it eats fuel a day more than car in a week... (~10 gal)... OEMs going bigger and bigger, more heavier duty
highly efficient or not - obviously something should be done ...


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## Ziggythewiz (May 16, 2010)

I've also considered mounting a blade under my bug, but someone made the gate a foot too small to get to the back yard...


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## TheRedBaron (Jan 31, 2011)

Thanks everyone for the information! The mower I have found to convert is a Dixon ZTR 4423. 

42'' deck with 3 blades
no hydraulics
fiberglass body 
Briggs & Stratton 16hp Engine 
Chain drive 

So hub motors for the wheels are probably out. Probably end up doing the single motor design. However, I am still thinking of doing 3 independent motors for the blades. Not only does that eliminate belt wear and tear, the overall efficiency of the system should go up as well. Also the system wouldn't need a really complicated controller.

On top of all that, it would make cleaning/removing the deck/changing the blades much simpler. The motors could be mounted to the deck. Add universal connectors to the wiring and that only leaves the mechanical structure to worry about.

Thoughts?

Side Note: anyone know what the torque of a lawnmower blade should be around? The rpm's should be around 3000 but the torque would vary depending on the motor used.

Side Note II: Though with the hub motors, while design maybe more challenging, since the power needed to the wheels is fairly small, the motors and controllers for that kind of set up would be much smaller hence less expensive.


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## TheRedBaron (Jan 31, 2011)

Also, let me apologize to anyone who spent a lot of time looking into the issue of the hydrostatic drive efficiency. I was initially under the impression that the mower I was converting was a hydrostatic drive. 

However, since I plan on performing more of these conversions, I probably will work on a mower with a hydrostatic drive so the information is still very much appreciated!

Plus other people get to use it as well!


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## ruckus (Apr 15, 2009)

Regardless of mower type, single moter is a good way to go for several reasons:

1. SIMPLE. 1 motor, 1 controller, 1 set of wires.
2. Hydrostat provides some back-pressure to help prevent runaway of series wound motors. With belt mower, this is more of a concern. Obviously, shunt wound is the ultimate solution here.
3. cost. one big motor is cheaper than multiple small/medium motors. Plus the cost of wiring and connectors etc etc..

I am glad you are doing this project. I have been DYING to do a mower conversion as our place eats gas mowers for lunch and the noise and pollution is horrible.

Can you post pics?

Please, please PLEASE can the powers that be create a mower/tractor/farm machinery conversion category in the forum??? 

Tractors have special issues that do not apply to cars such as the engine block acting as the frame.


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## major (Apr 4, 2008)

TheRedBaron said:


> However, I am still thinking of doing 3 independent motors for the blades.


Here's a deck I did a while back


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## ruckus (Apr 15, 2009)

awww. Talk about JEALOUS. 

There seem to have been no Electraks sold in MT.  (at least I have never seen one)

Will you give us some specs? Series or shunt wound? Controller or hard-wired? If series, do you have to limit speed or do the blades provide enough limiting force? 

Thanks


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## PhantomPholly (Aug 20, 2008)

Nice lawn Major!


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## major (Apr 4, 2008)

ruckus said:


> Will you give us some specs? Series or shunt wound? Controller or hard-wired? If series, do you have to limit speed or do the blades provide enough limiting force?


It is from this thread http://www.diyelectriccar.com/forum...ions-deck-motor-riding-lawn-moweri-45125.html 

Glad you like it  And in case it is not in the referenced thread, the motor is compound wound and controlled by a single contactor.

And Pholly, I'll tell Tony you like his lawn. Mine never looked so good 

major


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## TheRedBaron (Jan 31, 2011)

major said:


> Here's a deck I did a while back


That is a pretty nice set-up. Interesting idea to mount the deck in the front. Have any performance issues due to that? Also, is that the motor situated under the seat? I would then guess that the batteries are under the hood.

@ruckus -> I will post pics as soon as I can


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## major (Apr 4, 2008)

TheRedBaron said:


> That is a pretty nice set-up. Interesting idea to mount the deck in the front. Have any performance issues due to that? Also, is that the motor situated under the seat? I would then guess that the batteries are under the hood.


I helped Tony build the deck to replace the original Electrak deck which was also front mounted. Tony likes it out there. He has a flat yard. Don't know how it would handle on hills.

He runs the tractor with a generator. Got tired of replacing batteries. He's run that thing for like 35 years. See that thread I referenced for details.

major


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## TheRedBaron (Jan 31, 2011)

After looking at a couple of threads it looks like using one motor for the blades is more efficient than using three separate ones for each individual blade. 

It also looks like having the belt system in place is still a good idea though that reduces efficiency so that the blade system can deal with individual blades slowing down. 

Any idea on the efficiency of a belt system or where I can look that up?

Also, what is a good place to look for motors? I am trying to find one in the 3.5 HP or 2.25kW range and haven't been happy with the selections.

Thanks!


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## Jimdear2 (Oct 12, 2008)

If you are going to use belt and need to search out a motor, look for one like a that won't run away if the belt breaks. Look for something like a Seperatly Excited (SepEx) or I think Perm. Magnet. There are some others as well. 

Ask the experts about what you might want.

Jim


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## major (Apr 4, 2008)

TheRedBaron said:


> Any idea on the efficiency of a belt system or where I can look that up?


Hi TheRed,




> Median efficiency of the surveyed industrial and agricultural
> belt types and constructions is 96 per cent. Within
> rated and application power levels, efficiency ranges from 90 to 99 per cent depending on belt type​


from: http://www.cptbelts.com/pdf/misc/energy_loss_and_belt_efficiency.pdf​ 
Regards,​ 
major​


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## TheRedBaron (Jan 31, 2011)

Hey Guys:

Here are some pics of the lawnmower. We have already removed the engine and if anyone is interested in a 16hp Vangard Briggs and Stratton (still runs) shoot me an email ([email protected]). (I don't know why you would be interested considering the forum we are on but....)

Anyway the transmission of the thing is all jacked up. The engine runs and the blades will turn on but the mower doesn't actually move. This inclines us to think we should just rip everything out and go with a motor for each wheel running off the chain final drive rather than try to fix up the transmission. I have also read a couple articles describing the issues these cone drives had so going with a technology proven to go bad doesn't give me a good feeling.

On the battery front, it looks like we will probably go with a thundersky or HiPower 100ah LiFeSO4 battery


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## PhantomPholly (Aug 20, 2008)

TheRedBaron said:


> Hey Guys:
> 
> Here are some pics of the lawnmower. We have already removed the engine and if anyone is interested in a 16hp Vangard Briggs and Stratton (still runs) shoot me an email ([email protected]). (I don't know why you would be interested considering the forum we are on but....)
> 
> ...


Oh my gosh, it's an old cone drive. What a blast from the past! I remember helping my boss put one of these on display 36 years ago when the technology was brand spanking new and I was working as a bicycle repairer at a lawnmower sales & fixit place....


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## TheRedBaron (Jan 31, 2011)

PhantomPholly said:


> Oh my gosh, it's an old cone drive. What a blast from the past! I remember helping my boss put one of these on display 36 years ago when the technology was brand spanking new and I was working as a bicycle repairer at a lawnmower sales & fixit place....


Wow! Dinosaurs ran on cone drives? Who knew?


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## TheRedBaron (Jan 31, 2011)

Update on the lawnmower's status. We currently have both of the wheel motors working! That just shows us testing one of them, but we did the other one as well.

Below is a picture of the current status of the mower. As you can see the new drive system of the mower is a lot different than the old cone drive. We are using a BLDC 500 Watt, 1000 rpm motor for each of the wheels. For the blade motor we will be running a 8 hp, 16 hp continuous brushed dc motor.

Our current issue is figuring out how to set up the control sticks. The controllers for the drive motors accept 0-5 volts. However, trying to get that sort of behavior mounted to the sticks is an issue because we still want to be able to have the reverse capability of the zero turn. The controllers have a switch that must be enabled in order to reverse the motor.

In other words we want some sort of functionality that looks like this:
+5v (full forward) ---- 0 Volts (stationary) ----- +5v (full reverse)

We were planning on using some sort of potentiometer set up but nothing we can think of would allow us to map this sort of behavior. If anyone has any ideas, that would be awesome because we are a bit stuck on this issue!


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## GizmoEV (Nov 28, 2009)

TheRedBaron said:


> Our current issue is figuring out how to set up the control sticks. The controllers for the drive motors accept 0-5 volts. However, trying to get that sort of behavior mounted to the sticks is an issue because we still want to be able to have the reverse capability of the zero turn. The controllers have a switch that must be enabled in order to reverse the motor.
> 
> In other words we want some sort of functionality that looks like this:
> +5v (full forward) ---- 0 Volts (stationary) ----- +5v (full reverse)
> ...


Either a circuit board to interpret the signals or maybe a simpler thing might be two pot boxes. One for the forward direction and one for the reverse direction. Hook the arms to a spring so that when going forward the spring connecting to the reverse potbox stretches and vice versa. Hook up the micro switch in the potboxes to enable forward/reverse as required.


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## major (Apr 4, 2008)

TheRedBaron said:


> In other words we want some sort of functionality that looks like this:
> +5v (full forward) ---- 0 Volts (stationary) ----- +5v (full reverse)


Hi TheRed,

Check out wigwag controls. They are dual direction input command devices used on handicap carts. I repaired one (installed a small Curtis controller) for a friend. Might be available on the Curtis web site. 

Likely those won't connect directly to your motor controllers, but may give you some ideas. I have seen a couple of examples of homemade devices which function this way. IIRC, had 2 pots, microswitches and relays with a spring centering device.

major


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## JRP3 (Mar 7, 2008)

Here are some wig wag pots, they also have hall effect versions:
http://www.tecknowledgey.com/catalog/default.php?cPath=54_55&osCsid=f9dc9165cb26880b4ce3de251a48d6b0


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## Anaerin (Feb 4, 2009)

You might want to look at this, I think it's pretty close to what you're looking for, done with a regular pot:
http://www.diyelectriccar.com/forums/showthread.php?p=1674


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## mizlplix (May 1, 2011)

Greetings to all. this is my first post here on the site.

By a strange coincidence, I am a mower mechanic for the local school district. I keep up a fleet of 20 riding mowers of all sizes and types. But, 14 are the zero turn type. 10 are the Hustler 72" Super-Z and 4 are the 64" John Deere Z-Trak type.

Both types use individual fixed displacement hydraulic wheel motors, but one has a unified double pump and the other has two/single pumps.

Not to start any bad feelings, but either would be easy to do a single DC motor to drive the hydraulic pumps and mower deck, (which is direct-belt driven). 

The hydrostatic pumps are of the positive displacement, variable volume type with a swash plate to adjust the output. *There is no torque converters or slippage involved.* they would be a great match for DC power.

The electric motor would need to be RPM controlled automatically by the controller. The deck is always an electric clutch. the variable displacement pumps would take care of for/rev and speed settings. 

Turn on the key, and the DC motor starts at a set RPM. drive off trailer to mowing location. start the deck with a toggle switch. A sensor would be needed to throttle up and down with load to stop over speeding when suddenly unloaded.

Oh, well , just dreaming.

MIZ


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## GizmoEV (Nov 28, 2009)

MIZ,

A permanent magnet motor or a shunt wound motor would be perfect as they keep a fixed RPM. If they are forced to spin faster then they regen and if slowed they pull more current to maintain speed. I have heard that shunt wound motors are better for this purpose because they handle the heat better. Another alternative is a SepEx motor. The controller on my Gizmo has a speed control mode rather than a torque control mode so it should be able to do the same thing and not have issues of over speeding when suddenly unloaded.


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## TheRedBaron (Jan 31, 2011)

mizlplix said:


> Greetings to all. this is my first post here on the site.
> 
> By a strange coincidence, I am a mower mechanic for the local school district. I keep up a fleet of 20 riding mowers of all sizes and types. But, 14 are the zero turn type. 10 are the Hustler 72" Super-Z and 4 are the 64" John Deere Z-Trak type.
> 
> ...


That may be more practical idea than you think. Considering the price of gasoline and where that is headed, starting to convert some of those mowers (both zero turn and standard) to electric may not be that bad of an idea. Considering the amount of mowers you have to maintain, do you live in a more populated area? I ask because if there is a decent college nearby you might be able to get a class full of engineers interested in doing such conversions. Plus with college funding you might even be able to get the entire thing paid for.

I say this due to direct knowledge. I am a Senior in a Big 10 school in the electrical engineering department and we are currently converting this lawn mower to electric drive for the city's maintenance department. As a community outreach program, we have received quite a bit of school funding that has allowed us to pretty much pay for the entire project ourselves.

In any case, I wish we had gotten a hydraulic system instead of a cone drive. The drive system setup would have been a lot less difficult though the hydraulic system may not have been as efficient as the direct chain drive we are using now.

As of now, we may just mount multiple over sized pots to give us the functionality we need instead of some sort of wig-wag pot. We have also thought about using string pots to map the behavior as well. If I have time, Ill post a drawing of what we are thinking about doing.


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## mizlplix (May 1, 2011)

My biggest concern on a mower conversion would be batteries.......where to put them and getting enough to run about a realistic 3 hours per day. Lithium for certain....

A zero turn is a lean and bare animal. I will measure a Hustler Super 72 today to get a size for the front and rear packs.

They are running the 31 HP Kawasaki V-Twin motor at present. what would be a good electric replacement?


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## JRP3 (Mar 7, 2008)

That might be a good application for a swappable pack so you don't carry around excessive amount of batteries. How many gallons of gas does a mower use in three hours? That should give you an idea of the kwhs you need in a pack.


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## Peter S (Mar 5, 2009)

I use 20 pc TS90ah in my mower and 1-1.5 hour is no problem

The mower: http://www.automek.com/evrider.php?page=1v


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## TheRedBaron (Jan 31, 2011)

JRP3 said:


> That might be a good application for a swappable pack so you don't carry around excessive amount of batteries. How many gallons of gas does a mower use in three hours? That should give you an idea of the kwhs you need in a pack.


We actually did think about doing a hot-swappable pack. Lithium batteries where out of our price range and lead acids for us to get the projected run time were too heavy/big for the lawn mower. However, we were able to find a compromise in the middle that should allow us to run for about 1-1.5 hours.

When we calculated the battery pack size for the mower, we hit a fairly high number even for only the two hours we budgeted to run it. Our calculations showed for a two hour run time on a 30 degree slope going 5 mph we would need a battery pack size of roughly 8.5 kwhrs. This of course was for only a like 44 inch deck, not one of the massive 72" ones. The plus side of course is having a bigger mower means that it can support more battery weight. 



Peter S said:


> I use 20 pc TS90ah in my mower and 1-1.5 hour is no problem
> 
> The mower: http://www.automek.com/evrider.php?page=1v


Nice! Those batteries must have cost something crazy though. At least the quote we got on them would have been more than the entire rest of the project. Also: BMS...ERRRRG!


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## JRP3 (Mar 7, 2008)

TheRedBaron said:


> Also: BMS...ERRRRG!


Or not.....


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## TheRedBaron (Jan 31, 2011)

Here is a copy of the calculations that we used to determine the amount of kwhrs we would need. Most of the numbers could easily be swapped for a different mower. However, you would still have to find how much power the blades alone would require to drive.



JRP3 said:


> Or not.....


True! It is nice to have a system that prevents your lithiums from exploding!


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## JRP3 (Mar 7, 2008)

I've never seen a large format LiFePO4 cell exploding without a BMS. I'm running my CALB 100's with no BMS.


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## TheRedBaron (Jan 31, 2011)

How do you then prevent under/over charging on the lithiums or a voltage imbalance on one cell compared to another? From my understanding of the situation, have over/under charged lithiums in series with each other can cause battery lifetime issues along with the potential to really screw up a battery(explosion may be a bit of a harsh term).

However, as a college student, I would say my hands on experience here is lacking. This is just what I have learned in the classroom and in research/talking with those who have dealt with lithium technology before.

So please, expand on this subject if you would! (why the electrical engineering department here does not have course on batteries is beyond me)


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## JRP3 (Mar 7, 2008)

First step is to get a closely matched set of cells. Then balance them, either top or bottom balance the pack, benefits to each method, the more closely matched your cells are the less it matters which you use. Finally, don't charge or discharge them to the max, which you should avoid with or without a BMS to maximize life. If you want a simple monitor you split monitor both halves of the pack, any differences between halves denotes a problem.


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## GizmoEV (Nov 28, 2009)

My experience so far matches what JRP3 says. I quit top balancing my pack 9 months ago and only charge to 3.485vpc and haven't see the supposed drift people say will happen. Remember this is specifically with LiFePO4 cells, not other types. I haven't tested those. I found less than less than 1% of capacity is above 3.45V when the ending charge current is low.


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## bennettdan (Sep 20, 2007)

If you are still looking for a solution to your 5v-0v-5v potentiometer issue look for some concentric shaft potentiometers here is a couple of links one to digikey and the other is a datasheet from farnell they make linear taper pots for guitar amps. You didnt say what resistance range you needed but farnell makes most standard ranges. If you use a concentric shaft pot you can wire one pot channel to vary resistance one way and the second channel the other direction and then use a SPDT relay connected to your reverse switch to change which pot channel has the input voltage. If you have any questions i can draw up a wiring diagram just let me know.
http://www.newark.com/jsp/search/browse.jsp?N=1001531+5094071&No=0&getResults=true&appliedparametrics=true&locale=en_US&divisionLocale=en_US&catalogId=&prevNValues=1001531&filtersHidden=false&appliedHidden=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D1001531%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_US%26divisionLocale%3Den_US%26catalogId%3D%26prevNValues%3D1001531

http://www.farnell.com/datasheets/576650.pdf


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## TheRedBaron (Jan 31, 2011)

bennettdan said:


> If you are still looking for a solution to your 5v-0v-5v potentiometer issue look for some concentric shaft potentiometers here is a couple of links one to digikey and the other is a datasheet from farnell they make linear taper pots for guitar amps. You didnt say what resistance range you needed but farnell makes most standard ranges. If you use a concentric shaft pot you can wire one pot channel to vary resistance one way and the second channel the other direction and then use a SPDT relay connected to your reverse switch to change which pot channel has the input voltage. If you have any questions i can draw up a wiring diagram just let me know.
> http://www.newark.com/jsp/search/browse.jsp?N=1001531+5094071&No=0&getResults=true&appliedparametrics=true&locale=en_US&divisionLocale=en_US&catalogId=&prevNValues=1001531&filtersHidden=false&appliedHidden=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D1001531%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_US%26divisionLocale%3Den_US%26catalogId%3D%26prevNValues%3D1001531
> 
> http://www.farnell.com/datasheets/576650.pdf


Thanks for the links, we have hit a dead end with the string potentiometers. We were looking at a couple small ones (1.5" draw, 5kohm) and they had a price tag of $325 - $365. Which is so far out of our budget it isn't funny. So I'll look into what you suggested and perhaps some of the linear actuating ones.


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## bennettdan (Sep 20, 2007)

The farnells pots in the newark.c om link are the third one down they are around 9 dollars. What i had in mind would be to use a joystick stye actuator with a push button to actuate a relay that would send the reverse signal to your controller and also change which pot channel that was sending the 5v speed signal to your controllers. I think i know the controllers you are using I have some that operate like that and they came off of some surplus scotters.


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