# Zero Turn Mower Conversion



## JohnCM (Nov 2, 2018)

I intend to convert my Wright 48" ZTR. My idea is to just replace the Kawasaki 21HP ICE and retain the Hydro Gear hydraulic pumps and wheel motors and the belt driven blades. The mower currently weighs 480 kg. 

This is my first conversion project and I have a lot to learn. Any advice will be really appreciated. My initial questions are:

1. Is a brush type DC motor most appropriate given that the hydraulics provides the braking and reverse functions? 

2. Would the Motenergy ME1004 have the appropriate power for the job?

3. Is the fact that the ME1004 is open framed and air cooled likely to be an issue given the dusty environment.

4. Is mounting the hydraulic oil cooler 100mm above the ME1004 likely to cause a problem? (It is currently mounted at this distance from the ICE and the no load speed of the ME1004 and the ICE are similar.)

Thanks


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## major (Apr 4, 2008)

Hi John,

I seriously doubt that motor, a brushed PM (Permanent Magnet) motor, will deliver the needed performance without overheating and premature failure. Maybe if you have thin grass and a small level yard. But I use a 48" ZTM on 2 acres, flat, but thick and often wet grass. I doubt that motor would do half before it smoked.

Suggestion: Get a wound field DC motor with controller, or an AC induction motor and controller. A forklift salvage would be a good place to start.

I've seen a few good conversions. One was used semi commercially and used a WarP9.

Regards,

major


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## JohnCM (Nov 2, 2018)

Hi major

Thanks for the advice. I had a feeling the ME1004 might not be appropriate. I will follow up on your suggestions.

Regards
John


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## JohnCM (Nov 2, 2018)

I'm considering the Motenergy ME1304 and the 10kW Golden motor. 

I wonder if either of these motors would be appropriate and provide performance similar to the 21HP ICE? 

Also, I wonder how much 48V battery storage I will require for one hour's mowing?

Thanks
John


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## brian_ (Feb 7, 2017)

JohnCM said:


> Also, I wonder how much 48V battery storage I will require for one hour's mowing?


Depends... how hard is that 21 HP engine working? If it is flat-out all the time (I'm sure it's not) that's about 15 kW, so 15 kWh for an hour of running time. That's a lot of battery for even a large mower, so I really hope the average power requirement is much less than the engine's peak output.

You could take a really rough guess at the energy requirement based on fuel consumption of the mower in its original form, if you happen to know how much fuel it typically uses and are willing to take a guess at engine efficiency (or Brake-Specific Fuel Consumption). What do you burn in an hour of mowing?


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## major (Apr 4, 2008)

JohnCM said:


> I'm considering the Motenergy ME1304 and the 10kW Golden motor.
> 
> I wonder if either of these motors would be appropriate and provide performance similar to the 21HP ICE?
> 
> ...


Hi John,

I've never heard anything good about that Golden motor. But have seen several problem reports. I'd avoid it. The ME1304 being liquid cooled with temp sensor, paired with a good controller, would be a viable option, IMO. Even possibly overkill, and certainly $. 

A lot depends on your conversion system approach. If you use the existing hydrostatic drive(s), do you really need motor speed control? Would a compound wound pump motor from a forklift work running constant RPM?

Battery? 48V Lithium. I'd guess maybe about 70-100Ah.

Regards, 

major


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## JohnCM (Nov 2, 2018)

Response to Brian

Thanks for your response Brian, it is very helpful. 

The ICE works hard when mowing and I guess uses around 6 litres or 4440 grams per hour while mowing (assuming the fuel SG is 0.74). If the ICE efficiency is 322 g / kWh (from the link you provided), that’s 13.8 kWh or an average of 88% full power? I hope this is incorrect, as I think it means a 48V, 100Ah LFP battery would only last 20 minutes? 

As a check, I calculate that the Mean Green ZTR http://www.meangreenproducts.com/cxr5260/ uses around 3.4 kW hour mowing. This mower is lighter than mine and is all electric - no hydraulics or belts. I don’t know if that explains the apparent 75% less energy used compared with what I calculated for my ICE mower above? I guess it uses regenerative braking and this might explain some of the difference?

I purchased a Ryobi RM480e https://www.ryobitools.com/outdoor/products/details/rm480e-electric-riding-lawn-mower to mow the house yard while I decided what to do about the ICE ZTR. It’s half the weight and much slower than the ZTR, however, I’m staggered at how little energy it uses. The State of Charge meter on the Ryobi seems inaccurate and it seems to have regenerative braking , however, it seems to only use around 1.5 kW while mowing? 

Response to Major

Hi Major, 

Thanks for the advice re the ME1304 and the Golden motor. I have been looking for a compound wound pump motor from a forklift but have not found one yet. 

I’m hoping my reply to Brian above includes some errors on my part? If I will only get 20 minutes mowing from a 100Ah LFP battery, I may have to keep the ICE? I’ll hate it even more after using the little Ryobi RM480e. Unfortunately, the Ryobi won’t handle the 7 acres of rough pastures I mow occasionally.

John


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## brian_ (Feb 7, 2017)

JohnCM said:


> The ICE works hard when mowing and I guess uses around 6 litres or 4440 grams per hour while mowing (assuming the fuel SG is 0.74). If the ICE efficiency is 322 g / kWh (from the link you provided), that’s 13.8 kWh or an average of 88% full power? I hope this is incorrect, as I think it means a 48V, 100Ah LFP battery would only last 20 minutes?
> ...
> I’m hoping my reply to Brian above includes some errors on my part?


I think that the method for the power estimate from fuel consumption is sound, but the BSFC may be optimistic for an engine running at part-load and relatively high speed. If the actual consumption of fuel per energy output is higher, that would correspond to the shaft power use of the machine being lower than this calculated result. The difference could be substantial.

Even then, the engine-driven machine is using a lot of power to run.



JohnCM said:


> As a check, I calculate that the Mean Green ZTR http://www.meangreenproducts.com/cxr5260/ uses around 3.4 kW hour mowing. This mower is lighter than mine and is all electric - no hydraulics or belts. I don’t know if that explains the apparent 75% less energy used compared with what I calculated for my ICE mower above? I guess it uses regenerative braking and this might explain some of the difference?


The hydrostatic system will definitely sap a meaningful amount of power; there's a reason that there's a cooling fan on a hydrostatic transaxle. There's a lot a fluid drag and friction happening just to allow the power source (intended to be an engine) to keep turning at high speed all of the time even when there is little useful work being done. V-belts are not great for efficiency, either.

Since any modern production equipment would use motors and controllers capable of regeneration, they should all regeneratively brake... if nothing else, it avoids the need for a separate service brake. With the low speed involved and most of the power going into the mower (rather than propulsion), I doubt that much energy is recovered by regenerative braking.



JohnCM said:


> I purchased a Ryobi RM480e https://www.ryobitools.com/outdoor/products/details/rm480e-electric-riding-lawn-mower to mow the house yard while I decided what to do about the ICE ZTR. It’s half the weight and much slower than the ZTR, however, I’m staggered at how little energy it uses. The State of Charge meter on the Ryobi seems inaccurate and it seems to have regenerative braking , however, it seems to only use around 1.5 kW while mowing?


The Ryobi probably uses the same techniques as other battery-powered mowers to minimize the power requirement - on the small push mowers this typically includes tilting the mower blade so only the advancing edge drags in grass, different blade shape, etc. This machine also has essentially no transmission loss. This is probably the same model that I stumbled across in Home Depot one day; the thing that I found most remarkable about it (other than that it was available at all) was that it used lead-acid batteries... presumably due to cost.


If, for instance, 

the engine-based power estimate based on ideal BSFC is double what it would be with a real BSFC, or 
the actual power requirement to run through the hydraulic systems is double what a more optimal direct electric drive would take,
then either way the average power requirement from the motor would be about 7 kW (or 7 kWh to work for an hour). Maybe that's a workable estimate for planning?



JohnCM said:


> If I will only get 20 minutes mowing from a 100Ah LFP battery, I may have to keep the ICE?


You could do the conversion, but also have a generator set which is carried for the occasional longer moving task to make a hybrid. I think I would rather just break up the job into sessions with recharging (and of course doing other work not needing the mower) in between... or find a way to carry more battery.


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## JohnCM (Nov 2, 2018)

Hi Brian

Thanks for your detailed response. I will assume a 7kW power requirement for planning purposes. I prefer to mow in short sessions, so if I can get 45 minutes on a charge, that will be fine.

I was also surprised the Ryobi RM480 used lead acid batteries. I ordered mine in November 2018 shortly before they arrived in Australia. I was advised the battery would be 100Ah. However, only the 75Ah version was imported. I initially cancelled my order thinking 75Ah would not be enough. However, the Ryobi representative convinced me it would be OK. He was right. I'm amazed by the efficiency of this mower. 

John


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## prof.fate (Jan 22, 2019)

On bigger tractors (4000lb ones) that are hydro vs geared the difference in hp used is 2-3hp.

I have 2 zero turns - a 14hp and a 26hp - 42" and 46" cut, both toro, both 2 blade decks.

Top speed is very similar, the 14 is maybe 15% slower - haven't raced them to be sure LOL. Fuel usage is about 1 gph in the 26 and 3/4 perhaps less in the 14hp.

The 4300lb kioti 35hp diesel tractor I have (for brush hogging pastures) uses about 1.2 gph under heavy load (72" mower) and before that I had a 1500lb kubota 17hp (14hp pto..so only 3hp to move it via whatever they use to rate this stuff). and it used just under 1 gph (4' mower).

Gas/diesel I understand well..elec..not so much..if it's 750w to a hp and you need say, 20 hp for a zero turn, that's 15,000w, 1.5kw?

I don't know the efficiency difference - I assume more friction loss in an ICE than elec motor, and the ICE has a 9-12amp alternator on it for more drag (hp used on that?)

And if you need torque you need to rev up the ICE where a motor has it from rev 1 if what I've read is true. Not sure how to factor that into needed hp.

More HP on a mower gets deeper/thicker grass and cuts it faster. BAsed on push mowers i've used over the years 7 to 9hp should be enought for 40-44" cut, 11hp should do 46" easily.

If it takes 3 to move it, say 4 with battery weight (include hyd drap) then 14-18hp motor should be sufficient, right?

Is there any 'loss' (other than to your wallet) of having a bigger motor? 

I knwo with an ICE it's usually more efficient to work a smaller engine harder than to have a big one that loafs thru life.



brian_ said:


> I think that the method for the power estimate from fuel consumption is sound, but the BSFC may be optimistic for an engine running at part-load and relatively high speed. If the actual consumption of fuel per energy output is higher, that would correspond to the shaft power use of the machine being lower than this calculated result. The difference could be substantial.
> 
> Even then, the engine-driven machine is using a lot of power to run.
> 
> ...


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## brian_ (Feb 7, 2017)

prof.fate said:


> Gas/diesel I understand well..elec..not so much..if it's 750w to a hp and you need say, 20 hp for a zero turn, that's 15,000w, 1.5kw?


You just slipped a position for the decimal point: 20 hp times 750 watts per horsepower is 15,000 watts, but that's 15 kW (not 1.5 kW).



prof.fate said:


> I don't know the efficiency difference - I assume more friction loss in an ICE than elec motor...


Yes, with an internal combustion engine there's a lot more internal friction, and there is also heat loss to the coolant (which is inefficiency because it is a heat engine), but that's all accounted for in the overall engine efficiency.

There's no logical comparison of the efficiency of an engine with the efficiency of an electric motor, since they are doing very different things.



prof.fate said:


> I knwo with an ICE it's usually more efficient to work a smaller engine harder than to have a big one that loafs thru life.


There's a most-efficient power level for any given engine. Higher power and lower power are both less efficient; to look at it another way, for a given power level you lose efficiency by using an engine which is too big or too small. A too-big engine has too much internal friction and too much heat loss due to the swept area of the cylinder walls; too-small engine has too much internal friction due to excessive speed required and airflow restriction.

When I checked specs for Honda engines long ago, I noticed that they were rated by how much power they could produce at 3,600 rpm, but Honda recommended running them at 3,000 rpm for both efficiency and durability. In other words, if you wanted 5 hp, you were better off using a larger engine rated at 7 hp than a smaller one rated at 5 hp.

This applies to electric motors, too. The optimal conditions for efficiency will usually be less than full load, at some moderate speed... not the speed and load combination which results in maximum power output.


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## prof.fate (Jan 22, 2019)

brian_ said:


> There's no logical comparison of the efficiency of an engine with the efficiency of an electric motor, since they are doing very different things.


Please explain...both are turning a shaft to do work...

I went down this road to a degree with the HVAC on my home. Went from an old gas fired water heater (no steam so not a boiler). 60% efficient they guessed (too old to be rated). So 40% of my heating dollar went up the chimney.

MY math, most disagreed with , said elec boiler was better - 100% efficient. SO I went that route - combined gas/ele was $530 went to about $350 with the new system. (elec was 80/mo w/ gas furnace)

I've since moved to a 98% gas forced air with heat pump, a second heat pump in an addiction (can't get duct work there) and a second building with elec forced air - elec bill is up (duh) and gas is WAY down - I'd say $250-300/mo avg, plus I have a/c now and am running THREE furnaces. And I'm more comfortable with the forced air over hot water.





brian_ said:


> This applies to electric motors, too. The optimal conditions for efficiency will usually be less than full load, at some moderate speed... not the speed and load combination which results in maximum power output.


There is also a likely a savings on the equipment - anything run at the limit will not last as long as something run at 80% of it's limit.


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## brian_ (Feb 7, 2017)

prof.fate said:


> Please explain...both are turning a shaft to do work...


An engine starts with fuel; an electric motor starts with electricity. Saying that these are the same and comparable in performance is a bit like saying that a bicycle rider and motorcycle rider should have the same performance, because they are both making a two-wheeled vehicle move down a road... no. In practice, an electric motor is often the very last part in a long chain of equipment, and further up the chain there is an engine (steam or gas turbine) doing the hard part of turning chemical energy in fuel into useful power (turning a shaft, which runs a generator).



prof.fate said:


> I went down this road to a degree with the HVAC on my home. Went from an old gas fired water heater (no steam so not a boiler). 60% efficient they guessed (too old to be rated). So 40% of my heating dollar went up the chimney.
> 
> MY math, most disagreed with , said elec boiler was better - 100% efficient. SO I went that route - combined gas/ele was $530 went to about $350 with the new system. (elec was 80/mo w/ gas furnace).


The gas-fired water heater was starting with gas; at 60% efficient it was obsolete, and a new one would be much better. The electric heater is trivially making high-grade electricity into low-grade heat... it can't be anything but 100% efficient, because there is nowhere for wasted energy to go other than into heat. When you compare the cost, you are comparing lots of economic factors having nothing to do with efficiency. If your electricity comes from a gas-fired power plant, you're burning much more gas by using your electric heater than if you used the gas directly in your heater... even your old junk heater would beat the most advanced power plant.



prof.fate said:


> I've since moved to a 98% gas forced air with heat pump, a second heat pump in an addiction (can't get duct work there) and a second building with elec forced air - elec bill is up (duh) and gas is WAY down - I'd say $250-300/mo avg, plus I have a/c now and am running THREE furnaces. And I'm more comfortable with the forced air over hot water.


The heat pumps are interesting, because they don't turn electricity into heat at all - they just move heat from the source (the outside air, presumably) into the building.


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## prof.fate (Jan 22, 2019)

so you're looking at the WHOLE SYSTEM regarding efficiency...the elec gen plant (assuming it's not a green source for my energy, or that I don't have solar panels on my roof).

That is probably the best way to look at things, BUT - it's not how the real world works.

In MY world, since the most limited resources I have are time and money, efficiency is in regards to heating my house is MONEY.

House is warm (or cool, depending on the season) and my utility bill is lower - that's more efficient USE OF MONEY, if nothing else. 

I've read that elec cars are coming - for economic reasons as much as anything else.
An ICE car has 2000 moving parts, an elec car 20 (so the guy giving the speech said). To fuel an ICE for a year can run $2000. Elec for the same distance of driving is $200-250 (so I've read).

Since you can now buy a brand new elec car for less than the avg new car 

we've reached the tipping point, as the futurist said in his presentation. So he's thinking it will take less than 10 years for the overwhelming majority of cars to be electric.

We converted from the horse to the car in less than 15 years - and had to build roads and a petrochemical industry to make that happen.

***** As for 'work' or doing the same thing - yes - a gas engine turns a shaft and an elec motor turns a shaft - and that rotation does the 'work' of moving a vehicle. If I'm looking to replace a 15hp gas engine I need an elec motor that will do the same work. How it starts or where it's fueled from has nothing to do with that selection.

If you're gonna calculate in the power plant's generation 'costs' (carbon emmissions, heat, etc) then you need to figure the cost of getting oil out fo the ground and turning it into refined gasoline at your local station, and all that goes into getting it there (trucks, roads, pipelines, refinery, shipping perhaps, etc).

That's all well and good - but few of us other than hardcore 'treehuggers' pay much attention to the big picture - it's like politics - it's all local. How does it affect ME, Personally? Till it does it's very abstract to most people.

There if food on the shelf at the grocery store today. It was there 50 years ago. The fact that farmers are now 2-3% of the population vs perhaps 40-45% back then is a big deal - to a farmer or those that sell to farmers. Has zero impact on my daily life how many farmers there are or where they grow the food or the fuel efficiency of the truck or the wage of the fruit picker or stock boy.

BIG picture wise, yes, there is a cumulative impact (climate change, poverty level, etc) but 99% of us give no thought to that.







brian_ said:


> An engine starts with fuel; an electric motor starts with electricity. Saying that these are the same and comparable in performance is a bit like saying that a bicycle rider and motorcycle rider should have the same performance, because they are both making a two-wheeled vehicle move down a road... no. In practice, an electric motor is often the very last part in a long chain of equipment, and further up the chain there is an engine (steam or gas turbine) doing the hard part of turning chemical energy in fuel into useful power (turning a shaft, which runs a generator).
> 
> 
> The gas-fired water heater was starting with gas; at 60% efficient it was obsolete, and a new one would be much better. The electric heater is trivially making high-grade electricity into low-grade heat... it can't be anything but 100% efficient, because there is nowhere for wasted energy to go other than into heat. When you compare the cost, you are comparing lots of economic factors having nothing to do with efficiency. If your electricity comes from a gas-fired power plant, you're burning much more gas by using your electric heater than if you used the gas directly in your heater... even your old junk heater would beat the most advanced power plant.
> ...


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## brian_ (Feb 7, 2017)

prof.fate said:


> so you're looking at the WHOLE SYSTEM regarding efficiency...the elec gen plant (assuming it's not a green source for my energy, or that I don't have solar panels on my roof).


Buying a green energy source is an accounting trick: yes, you can pay some company to trade "credits", but the electricity that arrives on the utility's wires still comes from the same source as is does for the person next door who just buys regular electricity.

Even with solar panels on the roof, if you're attached to the grid then every incremental kilowatt-hour that you consume comes from whatever is providing peaking generation on the system... usually coal and natural gas plants in much of North America.



prof.fate said:


> That is probably the best way to look at things, BUT - it's not how the real world works.
> 
> In MY world, since the most limited resources I have are time and money, efficiency is in regards to heating my house is MONEY.
> 
> ...


I agree. 
What is cheapest for the end user often has little relationship to what is most efficient or has the least environmental impact. I just wish that more people would acknowledge their real motivation, rather than claiming some moral or environmental superiority.



prof.fate said:


> I've read that elec cars are coming - for economic reasons as much as anything else.
> An ICE car has 2000 moving parts, an elec car 20 (so the guy giving the speech said). To fuel an ICE for a year can run $2000. Elec for the same distance of driving is $200-250 (so I've read).


The popular parts count would compare only the engine and transmission to only the electric motor and transaxle. It typically ignores the supporting cooling systems for an EV, but to be generous lets say it includes them. Now, what about the wheels & tires, suspension, brakes, and steering? There are far more than 20 parts in those alone, they account for a substantial part of vehicle operating cost, and they are the same in cars with engines and with electric drives. In a modern car, there are hundreds of body parts, involving a mass of wiring and devices... again the same regardless of powertrain. While little of this applies to a lawn mower (and yet the cost of the battery and controller make the electric mower more expensive than gas), the reality of modern automobiles is that the engine does not overwhelmingly determine the cost of operation.



prof.fate said:


> Since you can now buy a brand new elec car for less than the avg new car


I keep hearing this, and it gets really tiresome. There is no electric car offered for sale which is cheaper than a comparable (other than powertrain) conventional car. With subsidies from taxpayers the price can be low enough to be economically desirable when combined with operating cost, but the EV is more expensive to buy.

Of course, if you compare a basic compact car for the EV (e.g. Nissan Leaf) to an average of engine-driven vehicles including sports cars, AWD vehicles, luxury cars, trucks, and everything else that is out there... then yes, a compact car is cheaper than the average car, even when the compact car has a battery instead of an engine. Even cheaper, when you go to that Nissan dealer to get the Leaf, buy the US$12K Versa instead, or the more basic CA$11K Micra available here, since surely every vehicle is interchangeable: econoboxes must be about to take over the world! 

In fact, the Leaf (one of the least expensive EVs available) costs more than all but one of Nissan's other cars, all but one of Nissans SUVs, all but one of Nissan's trucks, and even one of their sports cars. It's way above the average... and this is in a brand that doesn't include luxury cars.



prof.fate said:


> As for 'work' or doing the same thing - yes - a gas engine turns a shaft and an elec motor turns a shaft - and that rotation does the 'work' of moving a vehicle. If I'm looking to replace a 15hp gas engine I need an elec motor that will do the same work. How it starts or where it's fueled from has nothing to do with that selection.


True, it has little to do with the sizing choice, if that's all you're considering... so there is no basis for comparing efficiency. The energy source certainly does matter as far as the rest of the vehicle is concerned, as it does to system efficiency.


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## prof.fate (Jan 22, 2019)

brian_ said:


> The popular parts count would compare only the engine and transmission to only the electric motor and transaxle. It typically ignores the supporting cooling systems for an EV, but to be generous lets say it includes them. Now, what about the wheels & tires, suspension, brakes, and steering? There are far more than 20 parts in those alone, they account for a substantial part of vehicle operating cost, and they are the same in cars with engines and with electric drives. In a modern car, there are hundreds of body parts, involving a mass of wiring and devices... again the same regardless of powertrain. While little of this applies to a lawn mower (and yet the cost of the battery and controller make the electric mower more expensive than gas), the reality of modern automobiles is that the engine does not overwhelmingly determine the cost of operation.



Tell that to VW LOL.
warranty and emmissions compliance are a large part of a cost of a car - now dealing with the old battery recycling or what not may be a factor in elec cars (not sure..don't own one, friends that have only leased and I never asked about the end-result of the old battery once it dies or the car is totaled/junked).

Most cars today need to be emmission compliant to 100k miles. An EV will be that without any 'work' or parts needed.







> I keep hearing this, and it gets really tiresome. There is no electric car offered for sale which is cheaper than a comparable (other than powertrain) conventional car. With subsidies from taxpayers the price can be low enough to be economically desirable when combined with operating cost, but the EV is more expensive to buy.


I've ridden in a bolt - other than the big tunnel it's to me a pretty typical car. MSRP is 34k, i'm told you can get one for under 30 - WITHOUT the gov't helping. A leaf, and I've ridden in one as well, is a tad smaller - btu that's relative - I've had several VW bugs/rabbits, a pinto - all much smaller than small cars today. My daily driver is a subaru outback - not a small car by the old standards but average by today's. A friend has one of the smaller GM suv's - not too bad inside, looks narrow from the exterior. They can run $40k loaded.

But if you spend $250/yr on gas, less eng maintnance, vs $2000/yr on gas after 10 years (i typically keep a car 10-11 years) I'll save 18,000 on fuel and a few hundred more on oil changes. Will I need to replace the battery pack? No idea. I have good luck with lion batts (in power tools, laptops, cameras) Just replaced one in a 7 year old laptop..last laptop had kbd/power switch issues before it's battery quit. I have good luck with lead/acid as well. (7 year old deep cycle in my camper, 5 yr old in my subaru..got 11 years out of one in a car once..still working when I replaced it.

ANYway, what IS the average car these days? An F150? I see a lot of little hyundai, kia, sentra's and civics tooling about, as well as SUVs and trucks.

I dislike spending more on gas (transportation) than necessary. Unfortunaely that often means buying an older less efficient vehicle vs a newer more fuel efficient one, when one factors in total cost.

My F350 was $4k with a gas enging, 9.5mpg. A diesel would do double that - BUT - cost $10k. I'd never save the difference in fuel costs. I need a truck so I have one - but I've put 4k miles on it in a year vs 20k on my subaru.

As for Leaf costing more than all other nissans...you need to sober up perhaps.

29.990 - https://www.nissanusa.com/vehicles/electric-cars/leaf.html

I worked at a nissan dealership a decade ago in service - trust me, they had MUCH more expensive cars THEN.

Now I haven't looked to see if that 30k leaf is some stripped loss leader car perhaps one nobody would really buy. But people buy base models all the time.

Of course, if you compare a basic compact car for the EV (e.g. Nissan Leaf) to an average of engine-driven vehicles including sports cars, AWD vehicles, luxury cars, trucks, and everything else that is out there... then yes, a compact car is cheaper than the average car, even when the compact car has a battery instead of an engine. Even cheaper, when you go to that Nissan dealer to get the Leaf, buy the US$12K Versa instead, or the more basic CA$11K Micra available here, since surely every vehicle is interchangeable: econoboxes must be about to take over the world! 

In fact, the Leaf (one of the least expensive EVs available) costs more than all but one of Nissan's other cars, all but one of Nissans SUVs, all but one of Nissan's trucks, and even one of their sports cars. It's way above the average... and this is in a brand that doesn't include luxury cars.


True, it has little to do with the sizing choice, if that's all you're considering... so there is no basis for comparing efficiency. The energy source certainly does matter as far as the rest of the vehicle is concerned, as it does to system efficiency.[/QUOTE]


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## brian_ (Feb 7, 2017)

*Trying to put the "electric cars are lower priced" thing to rest*



prof.fate said:


> As for Leaf costing more than all other nissans...


I didn't say that at all. Here's what I actually said:


brian_ said:


> In fact, the Leaf (one of the least expensive EVs available) costs more than all but one of Nissan's other cars, all but one of Nissans SUVs, all but one of Nissan's trucks, and even one of their sports cars. It's way above the average... and this is in a brand that doesn't include luxury cars.





prof.fate said:


> ...you need to sober up perhaps.
> 
> 29.990 - https://www.nissanusa.com/vehicles/electric-cars/leaf.html


I'm sober; I also have my eyes open. My comment was based on Nissan pricing in Canada, but the pattern is the same in the U.S.
*Nissan Canada*

Micra CA$10,488
Versa Note CA$14,698
Sentra CA$16,598
Altima CA$27,998
*Leaf CA$36,798*
Maxima CA$36,990
*Nissan USA*

Versa Sedan US$12,360
Versa Note US$15,650
Sentra US$17,790
Altima US$23,900
*Leaf US$29,990*
Maxima US$33,950
If you look at the facts, electric cars are not less expensive to buy than gas-engined cars in general or comparable gas-engined cars specifically. 



prof.fate said:


> I worked at a nissan dealership a decade ago in service - trust me, they had MUCH more expensive cars THEN.


I did not compare the Leaf in detail with Nissan's more expensive categories of crossovers and SUVs, trucks, or sports cars (or Infiniti-branded sports and luxury cars)... because the Leaf isn't any of those things.


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## Duncan (Dec 8, 2008)

*Re: Trying to put the "electric cars are lower priced" thing to rest*

Hi guys
A big piece of the cost of an EV is the battery

I don't know how much an engine costs 
BUT 20 years ago we were getting $2k for a Cummins 6 liter turbo - complete engine with all of the turbo and fuel systems including starter, flywheel and alternator

A petrol engine at the time was probably less than $1000 - and if anything it will be cheaper now

In contrast a 30 kWh battery pack is probably over $9k

Tesla reports that they are down to $100/kWh - so one of their 75 kWh packs will be costing $7,500

A LOT more than the $1000 for an engine


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## prof.fate (Jan 22, 2019)

*Re: Trying to put the "electric cars are lower priced" thing to rest*

I'm thinking you're comparing apples to oranges. You're comparing an engine price from 20 years ago to a battery from today. 

A NEW engine is way more than $2k or 1k for a petrol engine. WAY more.
https://shop.advanceautoparts.com/c3/engines/16033 plus that won't include all the external parts (EFI, starter, alternator, belts, etc)

The battery pack price is what, new price?

If a KW is 12c, then 75kw is $9.
If that takes you what, 200 miles? (i'm asking..)
And gas here is 2.43/gallon today, a car gets say 25 mpg (easy math) it's 8 gallons so $19.44.

You save $5 every 100 miles..avg today they say is 15k miles/year, so you save $750/year on fuel.

NO point in comparing a battery pack to an ICE...if you compare the motor/controller/batt pack to ice/fuel system/emmissions then it might be a closer/fairer comparison.

Also, what we pay for parts is substantially higher than what a manufacturer pays when they build a vehicle






Duncan said:


> Hi guys
> A big piece of the cost of an EV is the battery
> 
> I don't know how much an engine costs
> ...


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## Emyr (Oct 27, 2016)

The historic prices need adjusting for inflation.

Bank of England has a Sterling(GBP) inflation calculator. Compount inflation over the period 1998->2018 totals about 72%, averaging about 2.5% per year. I expect other currencies and markets have had similar inflation over the last 20 years.


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## prof.fate (Jan 22, 2019)

*Re: Trying to put the "electric cars are lower priced" thing to rest*

Those prices seem low...friend bought an altima 11 years ago and it was $32,000 THEN...way above today's 23k...

So I'm not sure what you get for these prices...I know some elec cars now offer 2 size batteries which dramatically affects the price.

Since you spoke of efficiency - if it takes X energy to move 3000lbs of car from point A to point B - and I"m assuming some loss from elec plant over the wires thru the charger into the battery - why is elec cheaper than gasoline? 

Since it seems to be less costly, by a lot, to fuel an elec car vs ICE, that's my conclusion.




brian_ said:


> I didn't say that at all. Here's what I actually said:
> I'm sober; I also have my eyes open. My comment was based on Nissan pricing in Canada, but the pattern is the same in the U.S.
> *Nissan Canada*
> 
> ...


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## Duncan (Dec 8, 2008)

*Re: Trying to put the "electric cars are lower priced" thing to rest*

Prof you are WRONG WRONG WRONG

An IC engine today costs less than $1000

This is the magic of mass production


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## prof.fate (Jan 22, 2019)

*Re: Trying to put the "electric cars are lower priced" thing to rest*

Show me my friend.
I gave you a link - NOTHING that goes in an automobile, new, is $1000 or anywhere close to it.




Duncan said:


> Prof you are WRONG WRONG WRONG
> 
> An IC engine today costs less than $1000
> 
> This is the magic of mass production


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## Duncan (Dec 8, 2008)

*Re: Trying to put the "electric cars are lower priced" thing to rest*

Prof - I know that Chrysler were paying less than $2K for a Cummins engine
That was a very expensive option - the customers would pay $12K extra for that option but we could make a positive margin at that price

The V10 that we were replacing cost less than half as much

Since then the cost of making an engine has gone DOWN as the engineers continued to improve things

It's what we do - at my plant over a 7 year period we more than doubled output with almost no capital spend

If you want to buy one engine - think about $10K+ 
If you want 500/day - then $2K


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## prof.fate (Jan 22, 2019)

*Re: Trying to put the "electric cars are lower priced" thing to rest*

None of us are chrysler and none of us are buying 10,000 engines. So WE don't pay that price.

Just like buying an elec motor for a project - we are not paying what tesla/gm/audi and the like are paying.

Same for batteries as well.




Duncan said:


> Prof - I know that Chrysler were paying less than $2K for a Cummins engine
> That was a very expensive option - the customers would pay $12K extra for that option but we could make a positive margin at that price
> 
> The V10 that we were replacing cost less than half as much
> ...


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## Duncan (Dec 8, 2008)

*Re: Trying to put the "electric cars are lower priced" thing to rest*

The comparison was NOT NOT NOT DIY cars

The comparison was OEM's and what THEY pay for parts


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## prof.fate (Jan 22, 2019)

*Re: Trying to put the "electric cars are lower priced" thing to rest*

Not in the discussion I was in AFAIK.

Since none of us are manufacturers..does it matter? No.

As for what they sell them for, as much as the market will bear - with the overhead (engineering, design, styling, factory space and machinery, gov't regs and testing, warranty, etc) the only differences in say, an economy car and an F150 is some extra steel.
Yet sales price there is a huge difference.

You see it more say, 10 years ago in a taurus and a windstar minivan - the van was $5k more.

Or today in a subaru outback vs forester - again, $5k or more difference and there really is no difference in content and almost none in size. 

It's all marketing.

What DO batteries cost? I bought a replacement for my laptop - $15 off amazon vs $140 for a 'real hp battery'. So is HP marking them up THAT much?

I also see it in R/C plane batteries - I can buy chinese 'brand' (if you can ll them that) batteries for 1/4 or less the 'american brand' battery.

And if you ship it it's $12.95..yet they can send them from china for $1.20!



Duncan said:


> The comparison was NOT NOT NOT DIY cars
> 
> The comparison was OEM's and what THEY pay for parts


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## dain254 (Oct 8, 2015)

Having only read the last few posts of this argument... some of the numbers that are out there on the internet are anywhere from $100-200/kwh that the auto manufacturers (GM, Ford, Nissan) are paying their sub suppliers (example Panasonic, LG Chem. Tesla it is hard to say what they are actually spending but I would speculate it's a little over $100. Salvage yards a person can find batteries for as cheap at $80/kwh - so long as a person is willing to start with used cells the consumer really isn't being gouged price wise. 

I can't agree with any of the automobile comparisons - the difference in fit/finish, practicality, features (and extra aluminum), ride quality, comfort... I could go on and on between a Ford fiesta and Ford F150 is staggering. I'm happy to spend 3X as much for a vehicle that meets my needs and does so with the immense comfort and pleasantness my F150 Platinum delivers. 

Back to zero turn mowers: There is a company called MeanGreenMowers, their website is meangreenproducts.com. I've been all over that website trying to work out what they determine to be an appropriate size battery for what the potential buyer wants to do. These are 52/60" decks I believe for the smaller ride on. Their "all day pack" is 3 of their LEM, which is labeled a 48140, so I'm thinking it may be a 48V140ah pack, meaning 6.7kwh? If that is the case they are able to mow on much less energy than is being discussed. There is a small image on one of the pages too that has a battery pack cartoon labeled 7kwh. So again... if done correctly an electric zero turn might be quite a bit more efficient than we all think!


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## DMA (Jan 7, 2013)

Indeed, back to the mower topic.

Regarding the ME1004, John, I'm currently using it in my Cub Cadet LT1042 conversion. Here's a photo of it, without the deck installed, just after I got it running:









The pack is made up of 16 100Ah LiFePo4 cells (Winston).

The transmission is belt driven hydrostatic. 

One piece of advice I'd give, if going with this / an air cooled brushed motor: Cooling is key.

Here's a graph of the temperatures after a bit of (heavy) mowing:








Without active (forced air / retrofit liquid cooling), it will get quite hot and you'll lose efficiency and runtime.


To give you an idea of what difference it makes, here's a graph of my compact electric tractor project  (which I must update the build thread on!!), after adding a forced air blower and fan, doing fairly heavy (rotary hoeing) work:









The pauses in loads are when it was turning on the headlands. The tractor is using 200Ah cells, so the pack has a much easier job supplying power. It's also using an ME1003 - the main difference to the ME1004 is a slightly lower RPM/volt. Here's a photo showing the attachment for work it was doing in that graph:









That work is really pushing the motor to its limits. I'm in the process of adding a liquid cooling jacket:
















Regarding the MeanGrean and Ryobi electric mowers, I'm curious to see what their runtime would be under a decent load (longer grass, wet as well). I suspect the numbers are for 'ideal' conditions. Then again, if they can eliminate a lot of the drivetrain losses (belts, hydrostatic), it's possible they need a lot less prime mover power to begin with.


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## [email protected] (Aug 1, 2019)

Thanks for pulling the thread back on topic and showing us a working proof of concept!

I'm also looking at a conversion because I have an old woods 60" ZT mower with a dead ICE. I see that as an opportunity for some fun.

Sounds like most folks have gone about doing the conversion by dropping a very large electric motor in place of the ICE and just accepting the drive train loss. I may end up doing that too, just to make this happen, but I'd like to at least explore the idea of putting 5 motors on this mower- one for each wheel, and one for each of the three blades. A compromise might be three for the blades and one to run the hydro steering.

I've looked at the Mean Green and Ryobi sites to get an idea of how big their blade motors are. I can't find that info. Does anyone own one so they can just go look at the motors and tell me how big they are?


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