Max II electric conversion

[eresle]

Has anyone tried or considered doing an electric conversion to a Max? It seems that it would be a perfect fit, remove engine, belts and T20, install a suitable motor on both jackshafts and fit the controllers and batteries. If AC motors were used you would get forwards and reverse easily. Have a separate speed control for each motor/each side.
It would be like having a split shift but without all the extra levers. No hassles with the T20 bands ever wearing, no hassles with the drive belts or clutches slipping, no engine servicing....
No noise..... that would be nice in the forest

I keep thinking about it but the range is the only possible downside. I can get 8-10 hours or more with a full gas tank. Just not sure how you would calculate the required battery capacity to get the same.

I think 3-5kw motors would be reasonable. The Vanguard is 18 or 23 HP, split that between two motors and use the half the HP rule of thumb for going from ICE to electric.

Is it just me or has anyone else ever thought about this?

Interested to hear your thoughts, get a discussion going.

[racerone3]

same concept, but in an attex http://www.6x6world.com/forums/gener...heeler-11.html

[Don]

Circuit a 1970

http://www.6x6world.com/images/broch...-wheeler-1.jpg

[Nick O.]

http://www.6x6world.com/forums/max-atvs/39213-all-electric-max-iv.html#post221274

[eresle]

Well, the Attex thread was interesting. Looks like a 22hp motor although he does state that it was probably overkill. 5KW AC motors with controllers are available for about 500$ each now if you browse that well known Chinese market place.
5KW is approx. 7hp, so a motor each side gives 14hp in total which puts you at over the 1 to 2 rule of thumb for electric to ICE.
But I am not sure that my maths really adds up. Can you just add the power available each side together like that? I am thinking of my Max II, I know there are times when I have one side locked and the powered side getting full throttle. So, presumably that powered side is getting all the available hp from the Vanguard engine. But then again, if you have split the T20 controls then you can go forward one side and reverse the other so each side is only getting half the available oomph I guess.

Am I thinking this through correctly?

[allwheeldrive]

I've dabbled with EV conversions many times before. But usually always fine one reason not to do it.
The two motor principle in theory sounds great but the motors must have electronic breaking built in or it won't work. Since skid steers steer by skidding (locking one side up with a break) just applying power to one side will produce a very gradual slight turn.

Make sure your motors are of correct RPM. A torque converter can do as low as 3:1 I think and you'll be removing that. So You at the very least can't go over the original small engine 3,400RPM or you'll be lacking any kind of torque. I'd be interested in a link to such 5,000 watt AC motors to see their stats. Most projects in this range DC motors of limited wattage is all that is affordable from what I've seen.

Lastly there is what I call the off road range paradox which keeps me from doing this. Electric cars actually consume very little power while maintaining high way speeds. The Tesla and leaf reportedly use less than 18hp because of such low rolling resistance and good aerodynamics. You can expect to use nearly your maximum HP nearly all the time off road even in a light machine due to how much ground resistance there is (See how many people it takes to push a car in neutral on a flat paved road, now try the same with a car on a dirt hill with a 5% grade..now try up a sand dune!) . So say 14hp. If your top speed is 20mph (realistically 10 mph under max load with 14hp on hills dirt mud) You can expect 1.28x more run time than say a Leaf. 150 miles at 65mph that's 2.3 hours. BUT that's with a FULL Nissan leaf battery back!! A leaf has a 192 cell battery pack made of $100 (on used market) 0.5kw cells It is impossible to afford or fit $19,200 worth of Lithium batteries in a Max II Realistically You can fit around 1/4 of these at $4,800. This would give you a 422 pound battery pack with 24,000 watt hours. Consuming 14hp 10,500 watts you'd get 2.2 hours or 22 miles of range off road. Now this is with the biggest pack I image you could fit and it now be a 1 seatter and really quiet over weight overall. 1/4 this battery back would be a more realistic 105 pounds and only $1,200. This is the size pack I imaged doable for such a project BUT now where talking only 33min of run time... and 5miles of range...
Spending $500x2 motors + $1,200 for cells + $400+ for charger balancer + misc hardware your looking at around $3,000 for a final price that is reasonable, but again
5mile range off road and 33min of fun.
This is why I've never done it myself. Its the kind of thing that make for a cool youtube video or something to show off putting around a flat grassy lawn. But beyond that not sure it be worthwhile personally if your intent is to make it function like a real all day off road machine.
Lead batteries are pretty much obsolete the prices of used Lithium cells especially leaf ones are so cheap it hardly makes sense to look at lead, even more so when lead can only realistically deliver half their rated amp hours without battery damage and weigh THREE times more! lol

[john swenson]

so how did the electric attex work ? was it a bust with it's limitations , etc. ? seems like a electric motor would still need to be used with the skid steer in order to have the right power for mud and turning tight . johnboy va.

[allwheeldrive]

It worked fine for his application. Didn't quite float stable with the added battery weight. He just used it for short runs around his property. In fact that's the reason I'm tempted all the time to do it. I've wanted to convert my Quadractor to electric. Never worry about carb tuning, fuel going bad all the little things that add up. 99% of every ride I've ever taken it on was less than 5 miles, that's a lot of back and forth around the yard haha. Sometimes taking a machine out for a spin for 15min once a week is all a machine is needed for. If that sounds fine electric is fine.
Ultimately He drove it up a steep hill and the added weight of the batteries tipped it over on him sending him to the hospital. Not sure if he ever drove it after that.

[john swenson]

interesting . you know back in the day there were a couple of manufacturers that made electric garden tractors for mowing . they were plenty strong and would go for 2-3 hrs. on a charge . he used one for a trackless train ride that pulled 3 cars that held up to 12 kids and adults. they were'nt fast but maybe could have been geared for a bit more speed . in fact the fellow that bought my ride manufacturing business had a co. design and build him electric units for the train we built . it pulls quite a bit of weight also. just a few thoughts on the matter ..... j.b.

[john swenson]

check out the videos of the '' daymak '' awd electric atv.. and the '' stealth '' electric atv. j.b.

[allwheeldrive]

Electric bikes are an entirely differen't animal.
Their power to weight ratio with batteries and reduced rolling resistance makes them a prime candidate for off road use. I suppose it makes sense a machine with 8x less chains, 6x less driven wheels, 5x less weight is going to be MUCH more efficient moving around off road and up hills. Something I really need to build.
I did make an off road electric scooter long ago. Had over 30 miles of range and could push you up any dirt hill. Top speed was only 17mph but it was quiet fun. Never ran the batteries down in one go would have taken hours. But that's what happens when you need less than 700 watts to move you around.

[Gene Boyd]

I believe Mudd-Ox in Shipshewana built one.

[john swenson]

a guy could buy 2 of those '' yvon martel '' electric sleds out of canada and put them together with a framework and a max tub and seats . it would be an amazing electric tracked machine but a pretty costly project i would think . johnboy va.