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SwiftE

139K views 698 replies 48 participants last post by  tomofreno 
#1 · (Edited)
I'm getting fairly well along on conversion of a 2001 Suzuki Swift so thought I would start working on a conversion thread. First a summary of the goals:
1) 50 mile (83 km) range at 55 mph (92 km/h) and 70% DoD
2) Around $20k total conversion cost including donor
3) AC motor for electric braking
4) Zero to 60 mph (100 km/h) in < 12 seconds plus shifting time
5) Less than 1C current draw at 60 mph
6) Less than 3C current draw during max acceleration
7) Complete conversion in about 3 months

Goal (1) pretty much meant lithium cells or a "lead sled" pickup. I decided on lithium hoping they really do last 3000 cycles at 70% DoD, so cost/mile is not much different than sealed lead acid cells (didn't want to deal with floodies). Lithium and goal (2) meant a light vehicle to lessen the required battery capacity to meet goal (1). Goals 2, 3, and 4 are difficult to meet together but I think the motor/controller I selected will do it. The light vehicle permits meeting goals (5) and (6) without too large Ah cells, so there is some chance of fitting them in the small vehicle. Goal (7) meant no custom vehicle, buy a donor and convert it.

So I ended up with:
"Donor":2001 Suzuki Swift, 1895 lb (861 kg) curb weight, 2624 lb (1193 kg) GVW, 1.3 liter ICE 79 H.P. peak at 6000 rpm, peak torque 70 lb-ft at 3000 rpm. Interior and exterior in very good condition.

Motor/controller: HPGC AC50/Curtis 1238-7501, 90 lb-ft max torque out to 3000 rpm, 51 peak H.P. at 3200 rpm with 96V pack sagging to 85V, 15 H.P. continuous. I was told 17 H.P. continous by email from HPGC, so 15 is likely conservative.

Batteries: 36 SkyEnergy 180Ah cells purchased from evcomponents. The Curtis is nominally 96V max, but shutdown is at 130V. Fully charged cell voltage is 3.6V per SE spec, or 129.6V, but I plan to charge them to around 3.45V to leave some room for regen.

Charger: Manzanita PFC30, about 35A max at 240V.

DC/DC converter: No name from Cloud Electric, 30A

Estimated performance: These numbers are from a spreadsheet I created which is available at electricnevada.org under "evcalculator". Note the spreadsheet uses 96V dynomometer data for this motor. I modified it to estimate performance with the higher pack voltage, 115V nominal.

Range at 55 mph: 50 miles (83 km)
Zero to 60 mph in about 13 seconds plus shifting time, so maybe 16-17 seconds?
150A current draw at 60 mph (0.83C)
550A max current draw during acceleration (3.06C)
Max torque 90 lb-ft out to about 3500 rpm
Peak 60 H.P. approximately

Some photos:

Main battery box installed and painted (16 gauge steel), wheel well behind it:
Water Auto part Engine Vehicle


Decking installed around main box. Box lid open with carpet pulled up:
Vehicle Car Jacuzzi Family car Trunk


Insulation and most of the cells installed in the main box along with two 400A fuses which divide the 36 cells into 3 groups. That is a battery heater where a group of 3 cells is missing. Cells are clamped in groups of 3, 5, and 6:
Games


Lid closed and carpet (Home Depot 16$ for 6'x8') down. The line in the carpet is a photo artifact. The rear battery box sticking up out of the wheel well holds 8 cells (since been painted gray to match interior):
Vehicle Car Van Minivan Nissan primastar


Front battery box (under hood) with 4 of 8 cells in place and battery heater visible on RHS. AC50 behind and below it, box for charging plug on the front of it:
Electronics Technology Machine Auto part Electrical wiring


Motor controller mounted on motor end mount bracket (1/4" steel) with 150 cfm axial fan (update: changed to 250 cfm), and aluminum shelf where the charger, electronics box, and DC/DC converter will mount:
Vehicle Car Engine Auto part


Close up of motor on bracket showing about 5/16" space between controller and bracket for air flow from axial fan which blows through a 4.5" hole in the bracket:
Auto part Bumper Machine Engine


All cells are now installed and I am finishing up wiring up the electronics box - main contactor, shunt, relays, potbox. Next up will be to pull the steering wheel and dash to install the heater core and TBS and Curtis gauges, then hook up the Voltblochers.
 

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#3 ·
It was my understanding that Lithium batts weren't as affected by cold as LA; do you think the battery heaters will make much difference?
Yes. According to the SkyEnergy spec charging is above 0 C or 32 F. Dave at evcomponents told me it is difficult to charge the cells at low temperatures, and they only take about a 60% charge at around 30 F. Night temperatures where I live are many times in the twenties (F) and sometimes around 5 F. The heaters are powered by 120VAC. The plan on cold nights is to plug them in prior to charging with the thermostat set to around 60 F and turn on the charger when the sensor gets to about 45 F - hopefully in an hour or so. They will be off the rest of the time. The temperature sensor is bolted to the battery clamp on one of the set of four cells in the front box. Each heater, which heats about 4 cells is only 35W, so will provide only gentle warming. I'm hoping that the insulation, small amount of heat generated by the cells during vehicle operation, and daytime temperatures typically above 35 F will keep them above 50 F or higher the rest of the day. One problem will be equalizing temperature of the front box with they other two since it is exposed to more air flow when the car is moving. I'll see how this setup works, and modify if necessary. I can add insulation to the outside of the front box. During summer I'll remove the front box top for cooling, and I have a 145 cfm bilge blower to put a bit of air through the other two boxes. Have to see if it requires more. Have to start somewhere and gather data.
 
#8 ·
Yes, PB6. HPGC said they use the PBF6, F for foot pedal. I've seem some postings of complaints, particularly non-linearity, but they seem to work well with Curtis controllers as they are designed for them. There are a lot of them out there, so you might expect some bad ones to show up. Hope mine is not one of them.
Tom
 
#9 ·
Hey Dan,

I think the main difference will be in acceleration at highway speeds, due to lighter weight (lithium cells) and higher current controller, 550A versus 400A. If you put a Curtis 500A controller in yours performance would be quite close I think, but a bit different due to the weight difference. I wouldn't expect to notice much if any difference driving on secondary roads and in town - unless you want to lay rubber. There is also of course the range difference due to pack energy/weight. Cell life is the big one to me as I am hoping for cost/mile similar to sealed lead acid cells. That is why I designed for max 70% DoD and 1C or less current at 60 mph.

Tom
 
#10 ·
looks like good engineering and a great build. bravo. I hope a BMS will be involved to protect your battery investment.

If you get the rolling resistance and aerodynamics dialed in on that sucker you will probably be looking at somewhere around 180 to 200 wh/mile at 55mph easy. This will mean with 15KwH usable battery capacity you will probably be looking at more like 70 miles of range.

I usually say good luck here, but you don't need any. You engineered it.
 
#12 ·
I hope a BMS will be involved to protect your battery investment.
I am using the Voltblocher shunt regulators with HCV and LCV signals made by Brian Blocher and purchased through evcomponents. I plan to use the HCV signal with a circuit being made by evcomponents to throttle back the PFC30 to about 1A output (been waiting for this for a couple months now though, with no response to my last email sent a couple weeks ago :confused:). I also am epoxying a thermal fuse (open at 200 F) to the backside of each shunt regulator board, and daisy chaining these with 12V to the "coil" side of a solid state relay to shut down the PFC30 if a board exceeds 200 F. If I can't get a circuit from evcomponents, I'll have to determine the input signal to the PFC30 Regbus that is used to throttle back the output based on thermal input and make my own. Anyone familiar with this?

If you get the rolling resistance and aerodynamics dialed in...
I used the equation from Bob Brant's book that gives rolling resistance as a function of vehicle speed, but of course that is some rough average. It may overestimate it, as I seem to get conservative numbers for range compared to what Brian Blocher and Dave Kois have posted for their vehicles under "ev performance" on this forum. I also don't know the actual Peukert exponent for these cells, and just used 1.02 as an estimate. However, to match their numbers for range I have to set the Peukert exponent to 1.0, and unrealistically reduce the drag coefficient and vehicle weight for their vehicles. I don't understand this. Range numbers are very difficult to interpret as many times the average speed and DoD are not reported, and average grade and whether the path was a closed loop is rarely reported. The drag coeff for the Swift was given as 0.32 and I just roughly estimated cross sectional area from a few measurements.

Engineering is good, but good luck is better. :p

Tom
 
#15 ·
I plan to use the HCV signal with a circuit being made by evcomponents to throttle back the PFC30 to about 1A output (been waiting for this for a couple months now though, with no response to my last email sent a couple weeks ago :confused:).
Have you tried emailing James directly? He's usually good about responding.
If I can't get a circuit from evcomponents, I'll have to determine the input signal to the PFC30 Regbus that is used to throttle back the output based on thermal input and make my own. Anyone familiar with this?
Have you tried contacting Manzanita and seeing what is required?
 
#13 ·
I think they have a healthy margin on it, but consider that it is made of $tainless $teel, and the number of cycles the spring and pot must undergo. I figured the time and materials I spent trying to make something reliable (don't want it to fail as I pull out into traffic) would have a much higher cost. I question whether there are a "lot" of problems as a proportion of the total population of these controllers in use. There are likely tens of thousands of Curtis potboxes out there on industrial vehicles and golf cars around the world. A few people complaining about bad potboxes on a formum like this can give the impression of "a lot of problems", when in reality it might be 0.01% of the population of controllers. It is of course a concern. I think the complaint about non-linearity is irrelevant if you are using a Curtis controller designed to use that signal.

Tom
 
#14 ·
I don't know, people have been complaining about the noisy pots in the PB6 for years on the EVDL as well as here. A noisy pot probably doesn't cause much problem in low speed forklifts. The stamped stainless steel sheet metal parts can't cost more than a few dollars, and the spring need be no more durable than any automotive throttle spring. Since they are probably made in China I'd be surprised if they cost more than $20 in volume. Even if they functioned perfectly I still feel they are way overpriced and can't bring myself to purchase one, but that's my personal hangup :(
 
#16 ·
Have you tried emailing James directly? He's usually good about responding.
Turns out Dave didn't receive, or didn't see my email. He said he will check on progress on the circuit and also have someone there send me info on pin outs for the regbus (some techs there also work at Manzanita).
Have you tried contacting Manzanita and seeing what is required?
Yes. Rich told me to short pins 1 & 3 to shut down the charger - I think. Been a while. I was just fishing for info from someone with experience. I expect I'll get the info I need from evcomponents. If not I'll contact Rich again.

Tom
 
#17 ·
A noisy pot probably doesn't cause much problem in low speed forklifts.
I would think it could be a real problem if you are inching up to a pallet or near a coworker, but dunno. I see a lower priced potbox is a bit of a quest on your part (posts on the soliton thread) :) We all have our pet issues, this was just a something I didn't think was worth spending much time on. I likely will if the PB6 starts acting up. :p
 
#18 ·
I see a lower priced potbox is a bit of a quest on your part (posts on the soliton thread) :) We all have our pet issues...
Yeah you got me :eek: I've struggled with the potbox issue for a while, going back to my AMPhibian build. I ended up with this one and have had no issues with it, very fine control http://www.cloudelectric.com/product_p/th-bz31686.htm
I've even toyed with adapting one of them for my car build. I realize it's an important piece but it should also be a simple and relatively inexpensive piece, at least in my mind. I should let it go, I'm obsessed :eek:
 
#21 ·
Indeed, but this isn't my thread and I'm not building a Swift ;) My '88 Fiero doesn't have one.
Then take your talk off this thread!!:p Yes, I am totally kidding. No TPS in a Fiero? Bummer. Wasn't there a TPS at some point in ANY Fiero? I would think that it would make it easy on 2 fronts: no need to fuss with adapting your accelerator cable and you (theoretically) would already know where Fiero parts are available. Also, isn't there a mega cheap pot at Radio Shack?
 
#23 ·
Completed the electrical box a couple days ago. LHS is the high current components, just the main relay (contactor) and shunt. RHS has the potbox, relays for passenger heater, 12V (off when charging), controller, DC/DC converter (off when ignition is off), and fuses.

Electrical wiring Cable management Electronics Electronic engineering Electrical network


Today was the day I dreaded for weeks, removing the dash to replace the heater core. The $140 shop manual I bought from a dealer was very helpful in determining what wiring connections (12 or so) had to be broken, it said "Disconnect wires." :D But it was not too bad. I got the dash and core removed, and new electric core in a "custom" aluminum frame installed, and heater re-installed in the car. I made the frame from 1/16" sheet by bending it in a vise. This is the new heater in its frame, slid into one side of the heater:
Bumper Electronics
 
#25 ·
how bad a job (hours?) was it to pull the dash for access? I am looking at it, and thinking I want to put the heater element in the duct jest outside the fan rather than pull apart the dash.....
It took me about 7 hours to pull the steering column, dash, and heater, make the aluminum frame and bolt the heater onto it, stick some foam to the sides of the frame, insert it into the heater box/re-assemble the box, and bolt the heater box back into the car. That was yesterday. This morning I wiped the dust off the back of the dash with a damp cloth, bolted it back in, and connected the heater wires to the leads from the relay located up in the electrical box under the hood (about 2 hrs), but have to reconnect the other wires. Also have to re-install the steering column.

It would be a good idea to have a manual if you pull the dash. It didn't say what wires to disconnect, but it did show the location of the bolts that hold it on, explained to pull the entire steering column and leave the steering wheel in place, and other required steps such as to remove the speedometer cable. These instructions are under the section on removing the heater box.

I think Canev uses a sheet metal box mounted between the heater box and blower, similar to what you are thinking. That might be less work, if you can make an airtight box easy, and figure out a way to make an airtight connection between it and the ducting. You don't risk messing up wiring that way, but you loose air conductance - two heater cores in the path. I was way disappointed when I saw I had to remove the dash - but I took inspiration from Atkill's complete disassembly of his Aspire.:D

Tom
 
#27 ·
Wouldn't it have been easier to use a block heater and water pump with the existing overflow tank for heating the car?
I looked at those block heaters a bit and only saw ones that were about 800W. I'll need more than that to defrost the windshield and heat the car much at 15 - 20 F or so. Seems like a nice solution if they had more power, or if you live where it doesn't get that cold.

Tom
 
#28 ·
#29 ·
Re-installed the dash and steering column yesterday. Altogether it took maybe 12-13 hrs or so to remove, install new core, and re-install everything. The electric heater is good in that there are no moving parts, no possible water leaks, no antifreeze required, and nothing to mount under the hood which is a bit crowded in this small car. It's bad in that for this car it is quite a bit of work to install the core. I may well have gone the block heater route, but I planned to install the TBS and Curtis gauges where the ICE temperature and and fuel gauges are and figured that would be easier with the dash off. Turns out there isn't enough depth to mount them there.

I don't have a thermostat, just a multi-position on/off switch with a few speeds for the heater blower, and a lever/cable that opens/closes the air flow path from the blower to the core change from ambient air to heated air. I obviously don't want the heater to come on when the blower is turned on during summer. I also don't want the heater on very long with the blower off. I guess I will pull 12V from the blower switch and add a heater on/off switch in series to provide current to the coil of the heater relay.

Tom
 
#30 ·
wow, this confirms my plan NOT to pull the dash! I do need to finish up though as it is starting to get cold in the AMs.... For your gauging, take a look at the pillar mount I put in mine, it came out really nicely I think! It took some fooling around cutting and bending the 'universal' ABS piece to fit well. I did a fair amount of trimming, and a little bending with a heat gun.

http://www.envirokarma.org/ev/13.Instruments.shtml
 
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