# Electric john deere gator :)



## crackerjackz (Jun 26, 2009)

Ok so im kinda hard to follow lately as i have many things going on lol .... Electric bmw and now our john deere gator blew so i started converting it today ...
Bought 4 transcanada deep cycle 140ah batteries for my 27 hp dc mars motocross motor which i dont use or hardly ... My question is as goes

The gas engine and tranny had clutch systems on them much like a skidoo does ... I was told this is only to compensate gas engines having no torque at low roms ... The engine use to be a 15 hp engine and im swapping in a 27 hp electric motor could i do away with the clutches and go direct drive to the tranny with simply a slotted belt to help in not hurting the tranny as would a chain drive ??


----------



## crackerjackz (Jun 26, 2009)

?? :s dunno what to do im hoping to get this thing working out of the garage tommorow night  ...


----------



## major (Apr 4, 2008)

crackerjackz said:


> ?? :s dunno what to do im hoping to get this thing working out of the garage tommorow night  ...


You know your motor isn't 27hp. You fried the brush rigging on your MC. This thing is much bigger. You need to get a significant ratio between the motor and wheel. Gear it for a reasonable top speed as low as you can tolerate. Use a single ratio; no shifting. And no clutches. Then keep an eye on comm arcing and motor heat. An ammeter would be handy. Look at driveline/brake drag, tire pressure, anything to keep the amps low. Good luck.


----------



## crackerjackz (Jun 26, 2009)

Motor is 27 hp mars electric dc motor ... Rated at 125 amps continuous and 200 amps 10 sec burst ... Yes i overloaded it with my motorcross but im guessing a top speed of 110 kmh and batterie sag was the cause ... If the gator drives 30 kmh ill be very contempt as it is only used to haul hay to feed the horses  ...


----------



## major (Apr 4, 2008)

crackerjackz said:


> Motor is 27 hp mars electric dc motor ... Rated at 125 amps continuous and 200 amps 10 sec burst ......


You can believe in fairy tales, but 27hp at 48V will require over 600A. I doubt you have the controller and batteries to do it. And if you did, that motor wouldn't last long enough at that current to qualify as a 27hp motor in my opinion.


----------



## crackerjackz (Jun 26, 2009)

Just calculated ... Agreed that 27 hp is 400 amps at 50 volts ..... :s either false advertisement or i didnt see right lol damn sure hope it will be good with the gator :s


----------



## major (Apr 4, 2008)

crackerjackz said:


> Just calculated ... Agreed that 27 hp is 400 amps at 50 volts ..... :s either false advertisement or i didnt see right lol damn sure hope it will be good with the gator :s


Always bugs me. Do they power rate gas engines by the amount of fuel you put into them? Why then do you use input power to the electric motor and call it 27hp? To me motor power for rating purpose is what comes off the shaft.

So start with 27hp shaft power. That's 20kW. Now consider it is 75% efficient. That means roughly it needs 27kW input power, electrical. If, if, if you had 48 Volts at the motor terminals, 563 Amperes would be required. But, at that level of current, the battery sags and you're likely closer to 40V. Now you need 675A to get 27000W into the motor to get 27hp out of the motor. And that motor won't tolerate that high current well at all; certainly not long enough to be considered a rated load. 

That's why it's not a 27hp motor on a 48V system


----------



## crackerjackz (Jun 26, 2009)

Got the motor installed today and all the electrical 12 volt system finished and tested ... Monday only thing left to do is install the batteries and put the pulleys on we decided to put two 4.5 inch 3 aa strap pulleys and reajust the size till something works like we want ... We have plenty of pulley sizes to try ... Once we get what we want we will buy a wide strap with teeth and its corresponding pulleys to avoid spinning and other issues  

Hopefully monday everything should be finished electrically  ill still need to tires to install and reinforce my roll cage and change the old plexiglasses


----------



## crackerjackz (Jun 26, 2009)

http://youtu.be/a8oJX8PnxDg

First spinup with a belts no tensioner .... 

Gator finished this morning at 1 am lol i ended up doubling the motor pulley and going with b size straps with a tensioner  all works well did 10 km with it from the gatage to my house this morning with it  ... Ill have to plug it into my laptop see the parameters and wait for my ampmeter to arrive before doing any moods ... Ill take mord videos today


----------



## crackerjackz (Jun 26, 2009)




----------



## crackerjackz (Jun 26, 2009)

The gator hard at work on a -36 with windchill day .... 

Ill take pics of the final motor setup when i go out this afternoon to try to program the controller a little better as i know im not at full throttle because of missing pedal mouvement with the pot box ...


----------

