Dreaming about an Insight-EV

[IamIan]

Originally Posted by Ecky

Hugely useful post, thank you IamIan.

I also need to factor in weather / temperature. If I'm going to be using an EV when it's 20-30 degrees below zero, I'm definitely going to be using a heater, and range will already be reduced by virtue of lower temperatures.

Is there any reason I shouldn't have the battery modules split, to help distribute weight? A double 24kwh Leaf pack could provide what I need, but I don't think I'd want all of that weight in the back.

Welcome ... happy to help.

Cabin Heating does use additional energy .. but compared to traction energy usage it is a small % .. you can make it an even smaller % influence by using targeting heating ... For example .. heated seats .. or heated heat pad ... more directly applies the heat energy to the target it is needed .. you .. Trying to heat yourself by 1st heating the cabin air is a far more energy intensive method of getting you warmed up .. ie it takes more wh/joules to accomplish the same effect on you.

Usually one of the biggest hit to BEV's in cold weather is the traction batteries themselves being cold .. For example .. The A123 cell in my PHEV battery pack at -20C the colder batteries have reduced their 'usable' capacity to about ~60% of what they have available at +20C .. from around ~2.9kwh down to about ~1.7kwh .. and if that weren't bad enough .. the colder weather also increases the cell's internal resistance .. a +20C battery pack might have down around ~200mOhms ... but it will be up to about ~600mOhms by -20C ... soo less usable kwh of energy .. and less usable kw of power .. That still work for my application ... but it is an effect that is still important to keep in mind when designing a BEV conversion ... to make sure it meets your needs.

That is the reason why Some OEM BEVs .. like Tesla's actually deliberately spend energy .. while charging and even not while charging to warm up the battery pack itself ... of course the specifics will vary from specific battery type to specific battery type .. but ... you can test these things... by doing test discharges while the battery is in your home freezer.

You can also ...like heat plugs and such used to get ICE temps up .. you can do similar things in the winter to get the Battery temps up .. not crazy hot .. but just prevent them from getting soo cold it has a serious effect on the vehicle's utility / usefulness.

Cold air is denser and will increase your wind resistance .. but it is a smaller impact than the 'cold traction battery' effect ... for example:

Looking at the Previous 'normalish' around ~60F air temp numbers.
The Gen1 Insight Need to supply to wheels:
~8.80kw to sustain 60MPH @90%Eff = ~9.77
~5.95kw to sustain 50MPH @90%Eff = ~6.61
~3.87kw to sustain 40MPH @90%Eff = ~4.3
~2.42kw to sustain 30MPH @90%Eff = ~2.69

If all else equal .. but air goes down to say 0C , the above changes to about:
~9.54kw @60MPH @90%Eff = ~10.6 -- Roughly ~8% more
~6.37kw @50MPH @90%Eff = ~7.1 -- ~7% More
~4.09kw @40MPH @90%Eff = ~4.5 -- ~5% More
~2.51kw @30MPH @90%Eff = ~2.8 -- ~4% More

Yeah ... it's a hit .. maybe as much as ~10% or so ... but the cold battery is the much much bigger potential hit ... cold air and cabin heat combined together would still fit int eh ~25% buffer from before ... but not usable kwh capacity loss from a cold traction battery.

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The good thing about distributing the weight is for handling and such .. trying to get it the final back to near OEM-ish 4 wheel front back , side side distribution is ideal .. depending on final physical sizes weights and such .. you might have to make a few compromises .. but near back to OEM 4 wheel distribution would be ideal.

The other aspect of weight distribution is to try and keep your center of gravity / center of mass .. as low as you can .. good thing about going with the gas tank idea you had .. Higher Center of mass = bad

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If you can keep the Traction Batteries themselves from getting that bitter cold ... the previous ~25% buffer will handle the minor bits of colder / denser air ... etc.

If you can't keep them from going down to those bitter cold -20C temperatures .. you will either need to vastly increase the ~25% buffer ... or , do opportunistic charging .. or it might not meet your cold weather needs.

The batteries do have a fair bit of thermal mass .. which will help some ... but only goes so far.

Of course you could do the brute force approach ... if you double your capacity .. up to about ~60kwh when warm ... even in -20C you should still have plenty more than about ~35kwh usable .. but .. that would probably be too much weight with Leaf Cells ... Maybe if you did something like a Tesla pack which would be about ~500Lbs of batteries+ the extras for wiring , pack structure , etc .. Before adding that much more batteries .. My 1st direction instead might be some of those efforts to keep them from getting bitter cold ... just like we make efforts to get and keep the ICE warm in cold winter too .. a little cold has little effect ... it's generally only down in the real bitter cold that there are large / significant performance effects ... ie when the traction battery itself (not air temps) is down bellow 0C.

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One other note about 'all that weight in the back' ... Still true all the stuff above but .. just keep in mind ... MikeD did drive around for some time with all the OEM weight stuff in the back ... +a several hindered pounds of lead acid battery in the spare tire well on top of that ... + the weight of the 5th wheel ... and it's hydraulics .. and electronics .. etc ... soo it isn't like the frame won't take it ... it's more like the suspension system would need beefed up to handle that much more ... and the car will handle very differently if you had that much weight there.

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Of course the increased Li resistance in cold weather is actually a good thing .. in a way ... the act of using what usable kwh of energy it will give ... that will itself help some to heat up the battery .. generally speaking most members of the Li-family are very energy efficient ... up around ~95% or so (depending on conditions) ... but even that 5% of say ~20kw of power to move the car ... is still all by itself an automatic about ~1kw of heating exactly where you want it on cold traction main battery pack ... inside the battery pack itself .. if the charger also did a little pack heating of it's own while it was plugged in .. the batteries might not themselves ever really get down to those bitter -20C temps.

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Just food for thought ... about ~25% increase in the spring rate of the springs ... ~1900Lbs +~25% = ~2,375Lbs ... that's a fairly easy part.

[rmay635703]

Originally Posted by Ecky

As-is, I've towed 1000-1500lbs behind it (~100lbs tongue) with 2-300lbs of cargo in the hatch, myself, my wife, our sheltie and her mother's border collie in it. The car was sitting pretty.

If you haven't already get Scott's upgraded rear insight springs.

Also as I'm sure you know you could always just get linsight and a clutch and make a phev insight using mostly stock + lithium

[Ecky]

I've been loosely following the threads, but I'm skeptical there's going to be a practical way to disengage the electric motor from the engine.

[IamIan]

Originally Posted by Ecky

I've been loosely following the threads, but I'm skeptical there's going to be a practical way to disengage the electric motor from the engine.

'practical' is the yet to be seen subjective piece to the puzzle.

The current approach being looking at .. will be easier / cheaper on those who would wish to install .. however it has many issues to resolve with trying to package all the stuff inside the tiny space inside the IMA motor shaft core handling the torques , and ~6,000 RPMs .. ect.

Worst case .. if it doesn't pan out .. even if everyone else on the project looses interest .. I will eventually (years) just myself do a Inner/Outer Shaft to a Inner/Outer Double Clutch .. it won't have to fit inside the IMA Motor Shaft core .. Just replace OEM single Shaft that goes from ICE through IMA motor with Inner/Outer Shaft , and replace existing single clutch with Inner/Outer Double Clutch ... I know that will work just fine .. but it would be a bigger project on those wishing to do such an install/mod .. thus the current efforts instead.

That Inner/Outter shaft and double clutch method is already out there from OEMs and such ... and increasingly more of them also ... With luck , I'll find one that doesn't need much modification .. thus avoid getting a custom part machined.

- - - - - -

It was also interesting to see how the 3rd generation Civic 17kw IMA Motor (2012 model tested) is soo very close to a drop in replacement for the 2000 Insight 10kw IMA motor .. mounting bolts all the way around exterior fit exactly .. only 3 things make not a direct drop in replacement:

#1> Biggest ... The center shaft connection is off shifted slightly about ~2mm.

#2> coil/position sensor stick out a bit (~1/4") too much on the back (ICE side)

#3> It uses more coils and position sensors .. but confident that part at least would be easily resolvable in the software of Linsight .. which has motor control anyway.

Mudder & Peter both have already separately from each other verified the MDM and all the electronics all ave plenty of extra margin to be fine with 17kw IMA motor instead of the OEM 10kw .. .the current opinion/guess is that the ~10kw was a result of limitation of the OEM NiMH batteries .. not so much a limit on the electronics or IMA Motor.

If Peter's experiments that showed OEM 10KW motor and electronics can handle over 15kw .. if that same kind of surplus also applies the 17kw IMA motor design .. that same +50% would bring that 17kw up to about ~25kw.

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Of course the whole ICE/IMA disconnect thing is to avoid the ICE losses in EV-Insight Mode ... But .. Anyone with just MIMA or IMA-C&C can push their Gen1 Insight into EV mode once they drive it to fast enough RPMs to enter fuel cut .. or if they don't want to wait for fuel cut .. than they can use FAS to be in fuel cut at any RPM .. Although without Peter's more power modes you'd be limited to the OEM ~10kw .. and without the ICE/IMA disconnect you have all the pumping losses of turning the ICE while in that EV-Mode.

I don't often use that MIMA-FAS-EV-Mode .. but when I do .. I try to be in higher gears to keep the ICE RPMs low .. and thus keep the parasitic ICE losses low as well.

Attached Graph of Power Consumption tests I did of those ICE parasitic losses ... Power is as seen coming out from the IMA battery .. and just for ease of reference also attached the ICE RPM at speed for different gears graph as well.

Soo .. For example down at about ~2,000 ICE RPMs the ICE/IMA disconnect would save the EV-Mode roughly ~3,500 Watts to not have to drive the ICE's Friction and air pumping .. ~2,000 RPMs in 5th gear is about ~90kmph (about ~55mph) ... As we saw previously .. The Insight itself with extra battery weight needed about :
The Gen1 Insight Need to supply to wheels:
~8.80kw to sustain 60MPH @90%Eff = ~9.77
~5.95kw to sustain 50MPH @90%Eff = ~6.61
~3.87kw to sustain 40MPH @90%Eff = ~4.3
~2.42kw to sustain 30MPH @90%Eff = ~2.69

~6.61 + ~3.5 = ~10.11

With only OEM ~10kw .. that would mean ICE pumping losses limit MIMA-FAS-EV-Mode to a max of about ~50MPH on flat level ground ... A bit faster without the extra battery weight .. but not much ... The ICE losses are larger at higher speeds than the additional weight increases rolling resistance.

[Ecky]

The 2012 HCH motor is... offset 2mm? Is it unbalanced, or.. ? I guess I'd have to see it.

I've personally done some "EV" driving with just an injector kill switch. It throws a CEL, and you have to open the throttle plate fully to get full assist so the pumping losses are huge. I found I wasn't really able to maintain any speed at all in 5th gear.

Anyway, with all the trouble to decouple the low-powered (and I believe, not terribly efficient by modern standards?) IMA from the ICE, would it not be easier to just add a second electric motor, and perhaps attach it to the CV axles or something? You'd keep auto-stop intact, and could have as much or as little power as you'd like. You could even use both motors at once when accelerating if you so desired.

^ I was thinking about this some weeks ago, and at that point, I decided, why even keep the gas engine? If you're going to add a new battery and electric motor, you can save yourself ~350lbs by removing the ICE and throwing some extra battery in there.

[jamesqf]

Originally Posted by Ecky

The car was sitting pretty low, but handling was still very good and braking was fine even going down some pretty steep mountains. I'm thinking pulling 350lbs of ICE and IMA related stuff out and replacing them with 6-700lbs of EV gear won't be a problem.

That's very different from my experience. Downhill is OK - I have MIMA, so regen takes care of most - but going around curves there's a distinct drop in handling with more than me. And uphill requires dropping into 2nd for anything more than about 5% grade.

Originally Posted by IamIan

Trying to heat yourself by 1st heating the cabin air is a far more energy intensive method of getting you warmed up...

But at least for me, it's not warming me that's the problem, since I always dress so as to be comfortable outside the car. It's keeping frost & condensation off the windows so I can see where I'm going.

[rmay635703]

Originally Posted by Ecky

The 2012 HCH motor is... offset 2mm? Is it unbalanced, or.. ? I guess I'd have to see it

Anyway, with all the trouble to decouple the low-powered (and I believe, not terribly efficient by modern standards?) IMA from the ICE, would it not be easier to just add a second electric motor.

The ima motor is perfectly efficient but the algorithm and mosfets driving it aren't the most efficient.

Linsight improves driver efficiency, if you can find a modern pin compatible mosfet the Ima will be no less efficient than new.

As for a second motor it's very tough, insight just doesn't have clearance for anything

[IamIan]

Originally Posted by Ecky

The 2012 HCH motor is... offset 2mm? Is it unbalanced, or.. ? I guess I'd have to see it.

No .. It's perfectly balanced ... just center of 17kw 2012 IMA motor doesn't lined up with the center of the ICE output .. even though the case mounting bolts line up fine.

Picture MikeD put together on his page:

Originally Posted by Ecky

I've personally done some "EV" driving with just an injector kill switch. It throws a CEL, and you have to open the throttle plate fully to get full assist so the pumping losses are huge. I found I wasn't really able to maintain any speed at all in 5th gear.

If you don't use the FAS injector kill switch ... just use MIMA or IMA-C&C to drive the ICE to fast enough RPMs that it goes into fuel cut on it's own .. you don't get any cell or error codes .. at least I never have .. it has only been the injector kill switch (for lower RPM use) that I ever got cell/error codes triggered.

Yes ... It isn't much power at all .. especially with the ICE parasitic losses .. I've only done it in low power states at lower RPMs .. parking lots , stop and go-ish traffic .. or low enough power that 5th LB is under 60% ICE Load.

On a flat (or very close to it) I can maintain a bit over 45 MPH in 5th for as long as my battery has power to give .. small hills are an entirely different story ... Maybe I'll do some runs to put firmer real world numbers on the face of it .. but my current setup still has all those ICE parasitic losses .. and I'm not running any of Peter's more power mods ... just a tiny bit of more power from the A123 pack being a nominal 156v instead of 144 .. ~8% more v and thus also ~8% more A .. or about ~16% more power .. and less internal resistance (thus less voltage sag) ... depending on pack temperature about ~40% less IMA pack internal resistance.

Originally Posted by Ecky

Anyway, with all the trouble to decouple the low-powered (and I believe, not terribly efficient by modern standards?) IMA from the ICE, would it not be easier to just add a second electric motor, and perhaps attach it to the CV axles or something? You'd keep auto-stop intact, and could have as much or as little power as you'd like. You could even use both motors at once when accelerating if you so desired.

^ I was thinking about this some weeks ago, and at that point, I decided, why even keep the gas engine? If you're going to add a new battery and electric motor, you can save yourself ~350lbs by removing the ICE and throwing some extra battery in there.

I guess .. it's just a mater of personal preference and how much one wants to do .. what final result one is looking for.

BEV conversion is 100% perfectly doable.

[IamIan]

Originally Posted by IamIan

On a flat (or very close to it) I can maintain a bit over 45 MPH in 5th for as long as my battery has power to give .. small hills are an entirely different story ... Maybe I'll do some runs to put firmer real world numbers on the face of it .. but my current setup still has all those ICE parasitic losses .. and I'm not running any of Peter's more power mods ... just a tiny bit of more power from the A123 pack being a nominal 156v instead of 144 .. ~8% more v and thus also ~8% more A .. or about ~16% more power .. and less internal resistance (thus less voltage sag) ... depending on pack temperature about ~40% less IMA pack internal resistance.

So ... I Couldn't sleep .. so .. went out and did real world proof run in EV-Mode.

Outside Air Temp ~45F
5th Gear
~4 Miles
~50MPH
Loaded IMA Battery held
146-145v 64-65A ~9.4kw for pretty much the whole time.

IMA Battery Temp Started ~66 went to ~77F .. not bad .. considering over 3C rate , and only cabin air fan for cooling .. and even @ ~95% energy efficient would still mean about ~470Watt heater running inside the battery the whole time @ that ~9.4kw output rate.

Consumed about ~30% of my A123 Pack's usable SoE/SoC Window , or about ~730Wh out of ~2.5kwh .. soo with ICE air pumping parasitic losses on a pretty much flat stretch of road got ~5.4 Miles per kwh .. If I had to .. Max I could do with parasitic ICE with the SoC/SoE window I use on my A123 pack would go about 10~12 Miles EV on flat road like that .. I suspect if continued to be pushed that hard continuously 9-10kw eventually (only a matter of time) the IMA MDM electronics , or the IMA motor .. one or the other might over heat .. more down around 4-5 kw continuous is probably better if one plans to do long runs with the OEM Gen1 IMA Motor.

Attached is the elevation graph ... technically I went up a slight incline .. ~5m over ~4 Miles .. but still pretty flat over all.

I upload the crappy cell phone video to my google drive .. phone doesn't do well in low lighting .. and it didn't rotate the video for some reason this time like it normally does .. but if you want to watch it you're welcome to.
Link

Keeping in mind probably a little over 1/3 of the battery power / energy used to achieve the above .. was wasted as ICE friction and air pumping.

Also keep in mind .. I don't usually use my system like that .. it's just not a very efficient use of the IMA Battery energy .. I usually use it to keep in LB more often and such like that ... only in rare low speed low power conditions do I ever use that EV-Mode .. I never go that hard of an EV-Mode for that long either ... But it does have that much power if needed for short periods.

Soo that's the example .. Which pretty much lines up fairly closely with the previous estimated calculations of of wind / rolling resistance / etc @ ~50MPH .. on flat level ground .. ~10.11 kw was the estimate ~60F .. Got ~9.4kw at 45F .. and with head light load the whole time .. soo a little better ~10% .. but fairly close to calculated estimate.