# Start of my Metro Hybrid Project



## Coyote X (Feb 22, 2009)

Hi. I am a regular over at ecomodder but for this project I figure I better go to the forum that deals with what I am building. I tried asking this on another site but it seems pretty dead compared to this one so I will post it here as well.

I recently built a Metro XFi Convertible with a custom frame and pretty much totally custom built everything. It is getting great mileage as it is but I always want better. About the only thing that will give it to me is to add electric hybrid drive of some sort. So I have been reading and thinking about it and what I want out of it is pretty simple hopefully. I am keeping the gas engine and going to attach a sprocket to the drivers side CV axle shaft. I will mount the motor somewhere under the hood. If I can get it to drive for 5 minutes at up to 35mph I will consider it a success. I would like more than that if possible but that is my baseline. There is pretty much no limit to what can be modified on the car so even if I need to move the firewall to make room that is only a minor job as it is no longer structural.



So far my plans are an Etek PMAC motor and a Kelly Controllers KBL72301 It has a 300A Max, 150A continuous current rating and can handle 72V. I figure 6 AGM-31 batteries seems to be good batteries for the price. All of these items are still up for debate so I am not stuck with using anything right now and am willing to change it all.

So far the only thing I have done is to print out the motor mounting bracket to proper size and use that to measure and see where everything fits.

  

An Etek will fit in there with plenty of room with only moving a few things around and moving the radiator a few inches to the left. I think I can go up to maybe a 36 tooth sprocket on the axle without clearance problems. I could go bigger I would just have to cut and move a few frame parts if that turns out to be a problem. The axle at that point has a maximum of an inch movement so the chain would have no trouble operating with that range of movement.

Anyone got any advice or recommendations before I start throwing money at this project? I have a pretty good background in fabrication and electronic work so putting it all together is not hard. I am looking to get this done by June if possible and try and keep it under $5,000 if possible.


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## tj4fa (May 25, 2008)

Coyote X said:


> Anyone got any advice or recommendations before I start throwing money at this project? I have a pretty good background in fabrication and electronic work so putting it all together is not hard. I am looking to get this done by June if possible and try and keep it under $5,000 if possible.


Hi. Interesting project.

That Etek motor template. Is it the same one that you can buy for about $60- here (scroll down the page - dimensions are shown on the enlarged image there that maybe you can fabricate your own with if you don't want to buy one). 

http://www.teamdelta.com/products/prod5c.htm

Maybe instead of cramming it in under the hood you can run it off one of your other wheels (like that tiny orange one on the back of the car in your photo)


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## Coyote X (Feb 22, 2009)

The template was from robot marketplace. I could easily make a bracket but for the price of it and the time it would take for me to make one it is not worth the trouble to make my own. Using that bracket I could easily add a single U shaped tube running to the main frame rail to attach the motor and have an easily removable system in case I need to fix something later on. I could also make some rubber bushings to cut down vibration of needed.

I really thought about getting the back end of an all wheel drive metro from Europe and using that for the electric drive but it would make future repairs a lot harder. I would have to wait a week or two for any parts for the rear end of the car. Another option is to extend the shaft on the transmission 5th gear cover and putting a sprocket on that. Again the problem is future maintenance and having to deal with fabricated parts that need machining. The easiest thing I can think of is to just get a hub mounted to the axle so that the sprocket can be changed as they wear and if the CV joints ever fail I can just swap to new ends on that same axle shaft to keep it going. I am trying to keep the car 100,000 mile reliable so I can drive it for years without having to worry about high maintenance problems.

From what I have seen brushless motors hold up well to long term use without needing constant maintenance. The only thing that will need to be looked at regularly will be the chain drive system. I could always use an automatic chain oiler like I run on my bike to make it last about 25,000 miles between needing a new chain and sprocket set. That would get me over a year of life for a set. The CV sprocket would be a pain to replace so the less I have to get to it the better.

That yellow rim was a spare tire I used while building the car. It has been done for 6 months now and is currently being driven.








My last tank was around 60mpg so for winter driving that isn't that bad. I built the car to be totally flexible in modifying it so hopefully this will be a smooth project without major problems.


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## tj4fa (May 25, 2008)

Coyote X said:


> Another option is to extend the shaft on the transmission 5th gear cover and putting a sprocket on that.


Putting the sprocket on the 5th gear shaft may not work as the ratio may way too high for the electric motor anyway. Having it on the CV axle would make the motor available to use with all gear ratios if I'm thinking right.



Coyote X said:


> The easiest thing I can think of is to just get a hub mounted to the axle so that the sprocket can be changed as they wear and if the CV joints ever fail I can just swap to new ends on that same axle shaft to keep it going.


Sorta like this guy's?


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## Jimdear2 (Oct 12, 2008)

Coyote X

Here is another possibility for you to investigate.

You say there is a AWD version of this vehicle. You might look into getting an AWD power take off unit (usually fits in place of a stub axle) and drive that with the motor. If my memory is correct, I think that you would find that there is a approximatly 3 or 4 to 1 ratio built into that unit. In effect giving you a gear ratio that would help keep your sprocket sprocket sizes reasonable. Reduce the load on the chain or belt. Allow you to move the motor into the tunnel or using a standard drive shaft all the way to the rear, into the area used by a rear differential on an AWD car. 

The additional gear reduction in the power take off unit might allow you to go to a cog belt drive (much quiter and no lube required) and for sure would eliminate any need for a slack tensioner needed with axle movement.

Just a thought,


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## Coyote X (Feb 22, 2009)

The European AWD version has a totally different suspension setup so I would have to replace the entire thing. Bad thing about that is the brake pads and rotors are not available in the US so putting new brakes on the back would require ordering parts from Europe and waiting. I am not totally against that but it would be hard to find parts for it in the future I am sure as Metros get older and parts start getting harder to find.

I like that one picture though it is pretty much what I planned on doing. Except the sprocket will be on the other side of the inner CV joint. I have 175/70-14 tires on it so I was figuring I needed around a 4:1 reduction if the car won't ever go over 70mph that should keep the rpms down under what the kelley controller can handle. It says 60,000/# of poles(8 on that motor)=7,500 rpm. If the electric motor is turned off I don't see why it couldn't spin a bit faster than that if for some odd reason I needed to go over 70. I doubt that will ever happen though because the way the aerodynamics of the car make it feel over 70 it is hard to hold on the road.

But as far as the motor and controller I think the ones I have listed seem like they will work well together since the kelley controller website even sells them together. I have been looking around at my options for batteries and there is a lot of stuff out there but I am really not sure how much capacity I actually need and how well the regen would work with something other than lead batteries. I guess I will put the batteries off for a while and worry about making a reliable drive setup first. That seems to be the biggest challenge to this project.

Once I get the motor hooked up I can deal with the rest of it. I will go ahead and order the motor tonight so I can start working on how to get it and the axle together and working. I think I will have any problems mounting the motor and drive system and just letting the motor spin free while I drive until the rest of the parts get ordered and installed. And if it turns out I can't fit it like I was wanting I will still probably use that motor and just have to get it connected to the ground some other way.


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## Coyote X (Feb 22, 2009)

Got the motor in and it will fit easy. The next problem is gearing. The biggest #50 sprocket that will clear is a 36 tooth. The smallest I can get for the motor is a 10 tooth. That gives me a 3.6:1 ratio and this is will be my rpm vs speed.


```
rpm   264   529   1057   1586   2115   2643   3172   3701       
mph   5   10   20   30   40   50   60   70
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So from some specs I have seen online that mars brushless has a maximum rpm of 4000. I want the car to be able to do 70mph so that gearing will be ok and keep the motor from overspinning. Ideally I need a 3.9:1 ratio and that would give me 4000 at 70. I would have to put a mid shaft and another set of gears to get that though. I really don't think the small rpm difference is worth doubling up the sprockets and chains.

Anyone see any obvious problems with that rpm range for the motor to turn? I am still not sure of the voltage or amps for the controller so if that matters it can always be changed to something else.


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## CBOY (Feb 13, 2009)

CoyoteX,

Could you go into a little more detail on how the electric motor will function in tandem with your gas engine. Will both operate at the same time or does the electric operate at lower speeds and the ICE at higher speeds? I'd just like to better understand what advantages you hope to see with this combination.


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## Coyote X (Feb 22, 2009)

I am thinking that for the regen I will put a potentiometer on the brake pedal that gets pushed before the unmodified hydraulic system. I have an old gamecube controller with an analog trigger that I could take out the trigger potentiometer and mount to the back of the pedal with a hole drilled through so I push the trigger before pushing the actual brake pedal down. That way I have regen without having to think about it and it should just work. 

For the throttle I could easily hook into the stock TPI sensor to get a 0-5V signal but I am thinking that I might want to do something else. Maybe put a switch on the dash to use either the stock gas pedal or a trigger located on the shifter to operate the throttle. That way if I am just driving electric only I can just use the gas pedal. If I wanted to use both or electric drive with the gas engine idling that would also be a possibility, like if it was really cold and I needed heat. I figure that would be the least likely way I would drive it though since if the gas motor is running I might as well drive using it. I might want to use the electric motor to help accelerate sometime though so that would be nice having extra power to put to the ground.

The idea behind this setup is I am pretty much at the limit of what I can get out of the gas engine as far as mileage goes with my current driving style. I have gotten a best of 118mpg on a 160 mile trip. I average 60-75mpg a tank when everything is running right. The extra weight will drop that number slightly but the ability to do actual engine off driving should more than make up for the slight loss in mileage. Around here there is no real opportunity to do pulse and glide and other hypermiler tricks without seriously annoying everyone else on the road so I normally avoid doing anything other than standard driving and turning the engine off when possible. With a working electric drive I can use that for the first 4 miles of my daily commute when I have to drive through a 25mph town and when searching for a parking spot at work. There are lots of times that the car needs to be moving around slowly so if I can use the electric motor to do that then I will be happy with the setup. I would love to be able to double my mileage with it and that would probably be my ultimate goal once I am sure the whole thing is actually working out.

At least the drive part of this thing looks like it will work. The sprockets hopefully will be in this week to actually mount the motor up. I ended up finding a 9 tooth #50 sprocket so I can get the gear ratios I wanted 



Now it is just a matter of finding some batteries to use. I am thinking of just getting some cheap dual purpose deep cycle/starting batteries from walmart for now and later on getting some Lithium batteries. LiFePO4 batteries are getting cheaper so waiting for a while seems like a good idea. I am just not sure how much capacity I actually need. The walmart batteries will let me get a feel for how things are going without dumping a massive amount of money in something that might not be worth it.


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## tj4fa (May 25, 2008)

Coyote X said:


> I am thinking that for the regen I will put a potentiometer on the brake pedal that gets pushed before the unmodified hydraulic system.


For regen using your direct drive method off the spinning CV axle, you should get regen to recharge your battery pack anytime the vehicle is moving except when your using the electric motor to drive the HEV. 
(Note: You may have to put some sort of voltage regulation on the regen so you don't throw too much power back into the battery pack when driving with the ICE at high speeds. You don't want to cook your batteries).

In other words, I wouldn't worry about putting a potentiometer or switch on the brake pedal.

Since the energized motor will create more drag on your engine as opposed to free-wheeling (and take your MPG down some) maybe you should put a manual switch in the motor circuit to selectively regen whenever you want to throw charge back into your battery pack. 



Coyote X said:


> For the throttle I could easily hook into the stock TPI sensor to get a 0-5V signal but I am thinking that I might want to do something else.


Hmmm... I think the Kelly controller uses a voltage input for a potentiometer signal (I may be wrong) so you could probably do that but this will get extremely tricky if you want to perform all the conditions you mention below:

Condition 1-Run ICE only 
Condition 2-Run off electric motor only
Condition 3-Running both ICE and electric motor (this is going to be the tough part and will take some additional thought...)

For Conditions 1 and 2, perhaps you can leave the stock TPI alone for running the ICE and install a (PB-6) potentiometer hooked up on the same accelerator cable to selectively operate the ICE or Electric Motor as shown below. For condition 3 you may have to come up with some other setup.

*ICE running - Motor Off*

.......*ICE*<--TPI----\---------Accel pedal released (ICE idling - M off)
..........................[ ]PB-6
M____Controller___l l_____________/ *.*____________5V - Switch open 


*.......ICE*<--TPI----/---------Accel pedal applied (ICE running - M off)
........................[ ]PB-6
M____Controller__l l_____________/ *.*____________5V - Switch open


*ICE off Motor Running *
NOTE: PB-6 potbox has miscroswitch that shuts off (and coasts) motor when accelerator pedal is released.

........ICE---TPI----\---------Accel pedal released (ICE off - M off - Coasting)
..........................[ ]PB-6
*M*____Controller___l l____________*.*__*.*____________5V - Switch closed 


........ICE---TPI----/---------Accel pedal applied (ICE off - M running)
........................[ ]PB-6
*M*____Controller__l l_____________*.*__*.*____________5V - Switch closed 




Coyote X said:


> Maybe put a switch on the dash to use either the stock gas pedal or a trigger located on the shifter to operate the throttle. That way if I am just driving electric only I can just use the gas pedal.
> 
> If I wanted to use both or electric drive with the gas engine idling that would also be a possibility, like if it was really cold and I needed heat. I figure that would be the least likely way I would drive it though since if the gas motor is running I might as well drive using it.
> 
> I might want to use the electric motor to help accelerate sometime though so that would be nice having extra power to put to the ground.


This is going to take some additional thinking on how all these conditions will work...



Coyote X said:


> The idea behind this setup is I am pretty much at the limit of what I can get out of the gas engine as far as mileage goes with my current driving style. I have gotten a best of 118mpg on a 160 mile trip. I average 60-75mpg a tank when everything is running right. The extra weight will drop that number slightly...


Along with the extra weight, your MPG number will likely drop some anytime the electric motor is spinning due to drag (especially energized).



Coyote X said:


> ...but the ability to do actual engine off driving should more than make up for the slight loss in mileage.


Won't know until you try the different combinations of driving. If you plug in to recharge rather than recharge on the go with regen, you might save on some of the MPG lost while spinning the energized motor, but you will pay at the plug-in electric end.

Another thing to consider is if the ICE engine is not running (idling) when using the electric motor to drive the HEV, is that other powered stuff won't work as normal.
-Vacuum assist power brakes won't be working the same if you have them (no engine vacuum when ICE is off).
-PSteering, if you have it, will be extremely tough unless you have a manual steering box.
-Other powered accessories that run off the ICE alternator will be only running off your accessory battery.



Coyote X said:


> Around here there is no real opportunity to do pulse and glide and other hypermiler tricks without seriously annoying everyone else on the road so I normally avoid doing anything other than standard driving and turning the engine off when possible.





Coyote X said:


> With a working electric drive I can use that for the first 4 miles of my daily commute when I have to drive through a 25mph town and when searching for a parking spot at work.
> 
> There are lots of times that the car needs to be moving around slowly so if I can use the electric motor to do that then I will be happy with the setup.


Battery power only should work good here.



Coyote X said:


> I would love to be able to double my mileage with it and that would probably be my ultimate goal once I am sure the whole thing is actually working out.


Double?? I dunno...but at least sounds like fun trying. 




Coyote X said:


> At least the drive part of this thing looks like it will work. The sprockets hopefully will be in this week to actually mount the motor up. I ended up finding a 9 tooth #50 sprocket so I can get the gear ratios I wanted
> 
> 
> 
> Now it is just a matter of finding some batteries to use. I am thinking of just getting some cheap dual purpose deep cycle/starting batteries from walmart for now and later on getting some Lithium batteries. LiFePO4 batteries are getting cheaper so waiting for a while seems like a good idea. I am just not sure how much capacity I actually need. The walmart batteries will let me get a feel for how things are going without dumping a massive amount of money in something that might not be worth it.


If they are going inside the car, I would recommend AGM (Absorbtive Glass Mat) batteries over flooded Lead Acid batteries for now.


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## Coyote X (Feb 22, 2009)

tj4fa said:


> For regen using your direct drive method off the spinning CV axle, you should get regen to recharge your battery pack anytime the vehicle is moving except when driving the HEV with the electric motor.


I thought about that as a way to keep the batteries full but it seems to me that running them down and charging at home would be my best mileage. but really I won't know till it is built. I at least do have a pretty good mileage computer built for the car that will give me all the information I need on what is actually working. It might be a good idea though to experiment with having it do regen while driving the ICE so I will have to try that also once it is done.

As far as the throttle, what I was thinking was to use a 7805 regulator to get 5V and use the a pot on a trigger to give me 0-5V. Then run to a double throw switch to select either the tps 0-5V or the trigger's 0-5V and send that to the controller. I don't think it would work good running gas and electric off the same throttle at the same time. I have to let off the gas to shift gears and I might need different power levels from each motor depending on what I am trying to accomplish. But being able to use it either way seems to be the most flexible till I know what I am doing. I could be wrong since this is all new to me 

The batteries will probably be under the trunk floor. The car has a raised floor with a 5 inch high duct channeling air from the front grille to a rear grille for aerodynamics. It gives me lots of room to put batteries somewhere hidden. I might have to put 2 batteries in the trunk beside the regular engine battery that is already back there depending on how big they are though. The trunk is separate from the interior.


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## tj4fa (May 25, 2008)

Coyote X said:


> I
> As far as the throttle, what I was thinking was to use a 7805 regulator to get 5V and use the a pot on a trigger to give me 0-5V.
> 
> Then run to a double throw switch to select either the tps 0-5V or the trigger's 0-5V and send that to the controller. I
> ...


I guess I wasn't clear on using the pot box in my line diagrams.

The only thing the ICE TPS shares with the motor control is the use of the accelerator pedal and cable. The ICE gets its 5V for TPS use as normal and the Potbox/Motor/Controller gets its own 5V source (from a toggle switch) when that system is used.

That way all you have to do is use the gas pedal for driving in each (ICE only or Motor only) mode.


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## dreamer (Feb 28, 2009)

The PMAC motor puts out a max of only 25ft/lbs torque. And by attaching to the axle you are bypassing all the torque multiplication of the transmission. Doesn't a Geo manual trans give a net 16x multiplier to the wheels ? And the engine puts out 70ft/lbs at least ? So even if you are getting a 4x multiplier from your sprocket ratios, you are only going to get 100ft/lbs PMAC to the ground compared to over a 1,000ft/lbs with the engine. That PMAC just doesn't seem like enough torque for normal acceleration under electric-only mode. Most EV builders strive not to annoy other drivers with really sluggish acceleration away from stops.

How about this ? Build a spacer between the mating of the trans and engine -- maybe two inches -- to allow space for a sprocket-coupling effectively lengthening the transmission shaft. Attach your PMAC motor using identical sprocket, since your PMAC will max output 5,000RPM at 72V and a 1:1 ratio would seem appropriate. The spacer could be made by stacking four 1/2" alluminum plates -- the outer two fulling rings and the inner two as a C resulting in a gap large enough for a toothed belt to run between the external PMAC and the sprocket attached to the transmission drive shaft coupler. 

To my mind, the only logical place to hybridize a car is to add your electric drive in between the clutch and the transmission. Of course, if we had inexpensive high-torque wheel motors, it would be simple, but we don't. Being limited to something like the ETEK PMAC, I think you really need the full capability of the transmission.


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## Coyote X (Feb 22, 2009)

If I can get 5000 rpm out of the motor I could gear it down a bit. The information I have seen on that motor says not to spin it over 4000 rpm. That is why I was using 4:1 to drive it so it doesn't over spin the motor when I am using the gas motor. I have room to put an idler shaft so I could gear it up or down further if needed. If there was a small 2 speed transmission I could put on there it would be great I guess.

I figure it would be kind of slow accelerating but I won't know for sure what it can do till I try driving it. I guess at worst I will have to put a sprag clutch on it and gear it down to like 8:1 so it gives me good 0-30mph acceleration. I would not be able to back up with it like that or use regen. But if it is slower than acceptable I will do it. The Metro Trans has a 3.25:1 1st gear and a 3.85:1 final drive. at 49ft/[email protected] That gives me 613ft/lbs going to the wheels at full power. I am hoping the acceleration is not that horrible with the electric. I will find out in a week or so hopefully if all my parts come in and I start mounting them up. If it doesn't work at all driving the axle directly I will next try driving the transmission and see how that goes.


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## dreamer (Feb 28, 2009)

"The Metro Trans has a 3.25:1 1st gear and a 3.85:1 final drive. at 49ft/[email protected] That gives me 613ft/lbs going to the wheels at full power."

I thought the gearing was taller than that, (like 4.39 final drive ?) but oh well. And 49ft/lbs seems really low. Even the 1.0L 3 cyl should have 58 ft/lbs, and the 1.3L 4 cyl should be 75 ft/lbs. I said 5,000 RPM because the specs for the PMAC said 70RPM per volt, and you were talking 72v, so 72*70=5,040.

Regardless, the PMAC is going to be comparatively weak with only a 4:1 torque multiplier. 

After I posted last night, it occurred to me that shifting the engine two inches is not a trivial thing to do. Exhaust, motor mounts, fuel lines, clutch lever and throw-out bearing, etc. I still think it would give the best result from the PMAC, but would entail a lot more work than just the spacer and sprocket/coupling extension I was envisioning.

A Sprague clutch with a much higher ratio might be a simpler setup, as you say.

I know you wanted to be able to run electric-only, but I've always wondered what the effect would be to just drive the engine crankshaft directly with the electric motor. Would this improve gas mileage by reducing the torque that the engine needed to produce in all conditions ? Would flat ground feel like coasting downhill to the engine ?


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## Coyote X (Feb 22, 2009)

The car being worked on is an XFi Metro so it has less power and taller gearing from the factory to get better mileage. It typically got 10mpg better than a base Metro. It was also lighter but since my car is no longer on the same chassis the weight thing doesn't match up to my car anymore.

I am hoping the car is not really terrible accelerating. It might be pretty lousy but I figure it won't take a lot of effort to put it together as I planned it so if it sucks I won't be out a huge amount of work getting it together. If I have to redo it somehow then the motor and controller can be used for the new ideas so I won't have a huge expense redoing it either hopefully.

I could attach to the shaft on the other end of the transmission and not mess with the clutch or move the engine over. Just get a longer shaft machined that sticks out of the 5th gear side cover. I could attach whatever sprocket/belt on there then and it would let me shift gears however I needed to. That would still require a custom machined input shaft for the transmission so if it ever breaks I would have to have custom parts made up again. The main reason I wanted to attach it like I did was to keep things simple and easy to fix. The car typically gets 15,000 miles a year and will probably still be on the road 10 years from now. So I am trying to keep it easy to maintain and find parts for.

I tried calculating the acceleration the car will have and the best I can calculate is it will be able to accelerate at 21 seconds 0-30mph if everything is perfect. So 30 seconds to 30 is not great but that seems to be about typical for low speed putting around town. If I can get that then I will be happy with it for now. If not then I will be trying some other ideas to get it able to do what is needed.


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## barntechsolar (Mar 5, 2009)

when I purchased my Etek motor, it seems that max weight of vehicle for that motor is about 800 lbs an max current for one minute is 330 amp. you do have lots to think about. I converted a full size street motorcycle to series hybrid electric. by using a small engine and alternator I kept the battery pack to 4 agm 12 volt U1. also, the controller is an old Curtis 1204 48 volt 225 amp model. my motorcycle can be seen here, www.evalbum.com/2196 should you spin that motor past 6000rpm, it will fly apart.


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## dtbaker (Jan 5, 2008)

I'm going to throw a curve at you and suggest that you do not try for continuous drive power from batteries.... The weight will offset most of the regen gain. I would suggest instead that you concentrate on capture and use of JUST the braking energy using an ultra-capacitor.

With a capacitor you can dump ALL the braking energy in as fast as you want; which you cannot do with any battery. I did some prelim calcs, and it looks like a big ultra will just handle one 'braking session'. http://www.maxwell.com/ultracapacitors/products/modules/bmod0063-125v.asp

Second.... I rode in an EV that had chain drive; it was noisy as heck and I was more than a little concerned as there was no scatter sheild. With a relatively small misalignment the chain could come off with some pretty serious consequence at speed... If I were going to do this I would consider AC hub motors on the rear wheels that could act as 'brakes' and motors.


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## Electric_Rav (Aug 11, 2008)

This thread is quite old but I'm curious as to if the "Metro Hybrid Project" was ever realized in the manor the author was hoping. 

I have similar aspirations for my Toyota RAV4

Instead of doing a full conversion of my RAV4 I'm toying with the idea of putting two Mars 1003 motors in the rear directly coupled to the axles at 7 to 1 ratio at 72 volts. Mainly to help the ICE accelerate and or maintain modest speeds of 40mph without the ICE running. If this actually worked, I would of course add a vacuum pump for the brakes and probably convert to a manual steering box.

I also understand the risks of regen braking from the rear wheels alone.

My budget is tight so a full conversion is not going to happen. I drive around 80 miles a day and if I can bump my MPG from 25 to 40, I think I would be happy. I have the opportunity to charge at work. Sometimes I have to bring the kids to school and then work from home and that is 6 miles round trip at 25mph. I sure would like to do that on all electric so 6 12v agms should do the trick I think. I also run other very short errends of 6 miles or less during the week. It seems like such a waste to start the ICE since by the time I get where I'm going it is hardly warm.

My concerns are:

Will 2 Mars motors maintain a 2200 pound vehicle's speed of 40mph on flat ground with only 1 gear ratio?

Again with the one ratio would 2 of those motors remotely get the vehicle moving up to 35mph on electric alone? 

At 75 mph would the motors fly apart? I guess it depends on the RPM and from I gather, they should not spin faster than 4000 rpm. If 4000 is the max then I'm afraid at 5 or 10mph they would be spinning pretty slow so acceleration may be pretty poor. That's what I'm thinking anyway. I've seen 72 volt bike conversions on youtube and they seem to get 600 to 800 pounds of bike and rider going pretty fast and quickly I might add so if I could get half that I would be happy.

I'm trying to keep this simple so no clutching systems or CVT pulleys. 

Any advice is truly appreciated. If this idea is not feasible, I might as well sell the little truck and get a hybrid like a honda civic and be done with it. I test drove a 2008 the other day and went 18 miles of mixed highway and city driving and got an average of 52mpg but the thing was priced at 13K. Or I can just not do anything and just keep driving a 25mpg vehicle.


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