98 civic EV Build

[joejoe317]

Hello everyone, I am a Electrical Engineering student and have been thinking about a EV build.

Being able to obtain 50+mpg in my car has been difficult with 0 modifications to the car, but the car is starting to have some issues.

I think the overheating problem is fixed, but now I have to replace my cat and intake manifold.. Not expensive compared to a EV conversion, but we'll see what I can do.

I have been researching about batteries. Going into this I felt I could not do this with lead and needed lifepo4 like everyone recommended.
......

then reality kicked in, and I saw the pricing of lifepo4 batteries......

Until I was able to research more and found the a123 20ah pouch batteries.

If I could get these for about 20bucks a bag I believe I will be able to pull of this build.

Here is what I need from the community if anyone is willing to help me out here. Finding parts and explaining / motors/ controllers/ bms/ what happens to your electronic and vaccuum componenets after ice is removed?

I am trying to consider anything I can think of....

MY first question is this..
If I get array of these pouches... say 30X5

then it should be rated at 30*3.2 in series= 96v
and 5 in parallel would result is 100ah.

My goal is 200ah, if I can get 1$ per ah or less I think I could upgrade to either more voltage, or more range (ah)

would 96v convert to a sufficient highway speed?

I wouldn't mind hypermilling like I usually do, if that makes a difference...

my usual commute is to and from school... here is a typical driving setting....

drive on flat ground to the freeway... apx 2miles away... drive apx 40miles to class (one way) on a flat freeway...

I would really like to maintain AT LEAST 60mph

this means (unless its bad for the batteries) driving to 65 then coasting to about 57 then back to 65... rinse and repeat.

Side question: with electric vehicles has anyone see cruise control, and if so have they seen hypermilling cruise control, or is it even possible?

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2nd questio
are different motors more "fuel efficient?" I know that the motor isnt like the motor in our cars, but it does require energy to drive it. I know typically energy transfer is way more efficient then fuel... I hear with fuel we burn away 75%

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What kind of range and mileage could I expect out of these following conditions..

sunny and clear (wind negligible)

rainy hard(10mph headwind)

again on this flat surfaced freeway... @ most maybe like 6 overpass ramps.. I usually get going to a decent speed then kind of coast up them while slowing down, then at the top of the hill I will speed up, then coast down the other side.


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From what I researched I can use my manual transmission in my civic... How does this work? Are all 5 gears used?

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We can discuss deals/and other parts further later.. I would like to get these questions clarified first before asking others unless you feel that I really need to know something.

Thanks again for this community......

Also, if I go ahead with this conversion I will make an underbelly for it....As far as a boat tail..... probably not.

[joejoe317]

ok so the guy with the batteries emailed me back.there were 2 battery types. One with tabs and one without...

this is what he had to say.

Glad to hear from you !
You are right, there are two types of these batteries.But They are all real A123 20AH cells.Difference is the tab.
The pic with holes is do for e- motor.The discharge current is not large.so the connection you see in the pictrue is ok!Also I can provide you the ones without any sand or holes.You do this yourself as your requirment.
For example,I want them for a large discharge, so I can drill two holes one each side of the batteres ,with two screw and wire.(Each side can drill 4 holes max).
The price as you want more than 100 pcs. I can give you the price at 22 usd with shipment for 150 or 200 pcs.For 250 and 300 pcs. I can give you 21 usd per cell with shipment.This price is for most Europ country and USA,Will you please tell me where should I ship them to ?I use Fedex or DHL to ship them ,more safety and more quickly.
When you paid,I will ship them to HK.this may cost 5-7days. there they will be shipped by DHL or Fedex.Also this time, I will give you the tracking number, Usually it cost 7-10 days to arrive at you!
About the BMS,Please tell me more about the pack,Such as discharge current.
These batteries are the cheapest to you as new ones I think.
I don't know is I have answered all of your questions, Any questions, Please contact me!
best wishes

[Ryland]

David Harrington's 1996 Honda Civic is one that is finished and on the road, 96v is giving them a top speed of 65mph, that would be a pedal to the floor top speed, I suspect that it doesn't take much to get up to 45mph, a little longer to get up to 55mph and that 65mph takes a long stretch of highway, so if you need to go 65mph I would go with a higher voltage, less voltage sag and if you don't need the top speed then you don't use it!
144v is common, so there are a lot of components that are designed for that voltage including chargers, controllers, contractors, dc to dc converters and so on.
With those pouch cells, they can not be loose, they need to be under pressure or the chemical reaction inside is not a fast or complete, so they don't perform as promised, if you look at sets of lithium batteries you will see them banded together or threaded rods holding them together, at our local electric auto club they were talking about putting lithium batteries in a press or vise to get the banding around them and not finding a max pressure rating but more so the max pressure is how strong your end plates on your banding is.

Transmission, most people put it in 2nd or 3rd gear and "forget about it" but being able to shift gears is nice for highway speeds and for climbing hills, you might for example find that 2nd gear in town works and 4th gear in the freeway works well.

[joejoe317]

Thank you for the link...

from what I read on his (as far as batteries) is that he is using 96v and 170ah

his specs
Top Speed 65 MPH (104 KPH)
Driven 35-45 MPH mostly, I have maintained
55 MPH with AMPs and throttle to spare.
Acceleration Decent
Range 32 Miles (51 Kilometers)
Range is 32 miles at 40-45 MPH hilly
terrain to 80% DoD.
Watt Hours/Mile 270 Wh/Mile
I average 270 Wh/Mi while driving like a
maniac and have gotten 210 Wh/Mi while
conservatively cruising.

his range with hills is about 32miles @ 40-45 miles/hr and his top speed is around 60.

With these numbers I dont think my goal is feasible. Triple the range and 20mph faster...

Even with lithiums weight advantages and him having lead .... I still don't see the car going that far.

Basically I would like to go 100miles going 55-70.... I dont really want to drive 70, on the freeway I will probably drive 55-65.

Another big question I asked myself is what can make me go further and faster without increasing weight with more batteries (a few more might be okay)

Well.... on the freeway air resistance is the killer.

If people are seeing a 3% increase on belly pans of the 25% out of 100% of the fuel they use... That is pretty big numbers...

So I guess what I want to know now is...

on a flat freeway, what battery pack size would one need to achieve 100mile range from lifepo4 batteries?

I do have a 40mile commute to class one way, so If I can only go 32miles I am pretty f.... well lets say I will be stranded.

[Ryland]

If you really need a 100 mile per day range then you would be best off either buying a 50-70mpg vehicle or moving.
Those A123 system pouch batteries are a good deal and I know someone here who is talking about getting some too, they should also last you the rest of your life, but you would need $8,000 worth of them to give you your 100 mile goal and assuming you don't drive at all on the weekend, you're not going to brake even for 5 years and if I remember right those batteries are only supposed to degrade 30% after 2000 or more cycles, so that's ten years and you still have a 70 mile range, and of course -0- oil changes, radiators blowing out, no new exhaust systems, spark plugs or tune ups over that time either.

[joejoe317]

Those are some awesome benefits lol.... With the 8k dollar battery pack what are the specs your were thinking of... volts and ah?

[joejoe317]

btw on the trips to and from school I avg 45-55mpg... I would say high 40's just to be safe.

[Ryland]

Originally Posted by joejoe317

Those are some awesome benefits lol.... With the 8k dollar battery pack what are the specs your were thinking of... volts and ah?

If you bought 396 pouches and wired them up 149v and 180ah that would give you around a 26800 watt hour battery pack and if that other guy with a civic was getting 270 watt hours per mile with hard driving in a car with a lead acid pack that would be 99 miles with a lithium pack that size if you took it to 100% DOD, not a great idea, but it would give you an easy 70 mile if not 80 mile range and I would hope that for $8,000 worth of batteries that they would give you a small price break too.

[joejoe317]

Originally Posted by Ryland

If you bought 396 pouches and wired them up 149v and 180ah that would give you around a 26800 watt hour battery pack and if that other guy with a civic was getting 270 watt hours per mile with hard driving in a car with a lead acid pack that would be 99 miles with a lithium pack that size if you took it to 100% DOD, not a great idea, but it would give you an easy 70 mile if not 80 mile range and I would hope that for $8,000 worth of batteries that they would give you a small price break too.

Can I correlate my wh/mile to mpg?

For example on highway I can get 60mpg hyper milling ... Maybe 35-40mpg in town.

Can I then say my wh/mile will probably be more (less efficient) in town vs the freeway ?

He did say he can get 210/wh driving nicely. I can't guarantee I can beat that, but I'm pretty sure I can hypermile past that..

Can u hypermile in an ev (I only usually go as far as just putting the clutch in and coasting in neutral.

Side note: while driving I thought of regenerative shocks. Is there such a thing?

Does anyone here live in Oregon?

[joejoe317]

Sorry for the questions in random order.

Do u think a 120v 200ah would do the trick. I'm not sure how velocity scales with voltage especially with air resistance increasing with highway speeds