EV Digest 5329
Topics covered in this issue include:
1) RE: Battery Pack Heating - Optima Hawker links
by Cor van de Water <[EMAIL PROTECTED]>
2) Re: 96v charge only goes to 121.5 & 5 amps. Wrong resistor?
by "Chuck Hursch" <[EMAIL PROTECTED]>
3) Re: Motor options
by "Chuck Hursch" <[EMAIL PROTECTED]>
4) Re: Motor options
by "Chuck Hursch" <[EMAIL PROTECTED]>
5) RE: Which battery terminals would be at least satisfactory in my specific
application?
by "Roger Stockton" <[EMAIL PROTECTED]>
6) Re: Finally back on the road. AC Li-ion upgrade (Long)
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
7) RE: DC-DC converter: How to select?
by "Roger Stockton" <[EMAIL PROTECTED]>
8) RE: Motor options
by Cor van de Water <[EMAIL PROTECTED]>
9) A cleaner EV genset.
by [EMAIL PROTECTED]
10) single string, was: Battery Pack Heating
by Cor van de Water <[EMAIL PROTECTED]>
11) Re: 80 miles in a Porsche 911?
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
12) Re: Pusher trailers, (was Re: Porsche 911 Was: How many amps
driving my EV?)
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
--- Begin Message ---
Lee,
Did you mean "Higher Capacity" when you quoted "Longer Cycle Life"
in your 3rd point about keeping the batteries hot?
My understanding is that batteries that stay hot have very short life
and you confirm it in later statements.
My own experience confirms this:
During cycle tests I found that discharging a battery immediately
after finishing an agressive charge can give 10-20% more capacity
than after several hours of resting.
This means that continuous fast cycle-tests deliver optimistic
data about battery capacity...
The cooling down is most likely the cause of the reduced capacity.
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Lee Hart
Sent: Thursday, April 06, 2006 11:58 AM
To: ev@listproc.sjsu.edu
Subject: Re: Battery Pack Heating - Optima Hawker links
Mike Phillips wrote:
>> I'm not worried so much about range as I am about cycle life.
>> I think the cycle life of an ACP car and the NREL tests are
>> conclusive proof that controlled warmth is better.
Roger Stockton wrote:
> The NREL tests have been discussed onlist in the past and are riddled
> with problems that undermine their value.
My impression is that ACP got its long battery life primarily with cars
that used an ICE generator trailer for long trips. I haven't seen any
published data from them to document their battery's actual performance
(number of cycles, depth of discharge, typical currents and
temperatures, etc.) What I see is mostly marketing and anecdotal data.
I'm not saying they aren't getting good results; just that they aren't
defining what the results are, or how they are getting them.
The NREL tests are impressive on the surface, but as Roger said, there
are serious flaws. The "normal" charging algorithm they used as a
control was a *terrible* one that appears chosen to deliberately destroy
the batteries as quickly as possible. They ran the tests over a very
short time span, so calendar life was irrelevant, and they largely
ignored the consequences of temperature on capacity.
I was initially impressed by the NREL test, and tried to duplicate its
results on some AGMs myself. My conclusion was that:
1. They deliberately overcharged the battery to get it hot.
2. The higher temperature resulted in higher amphour capacity.
3. You only get the longer cycle life if the battery is kept hot, and
cycled quickly. If the battery rests or cools, the capacity goes
away.
4. The high temperature cause a very high self-discharge rate, and very
short calendar life (just a few months).
5. Batteries vented and lost water. They failed not from low capacity,
but from grid corrosion (excessive internal resistance) that
prevented
them from delivering enough current to be useful.
I did find that if you have old batteries like yours that can no longer
provide enough capacity, you *can* get a little more life out of them by
heating them up. I could take an old Optima down to 50% capacity, and
get it back up to 80% capacity over a few cycles by charging and
discharging at high enough currents to get it hot (120-140 deg.F). The
high temperature also lowers the internal resistance, which lets you
draw more current before the voltage sag gets excessive.
But let it rest for even a few hours, and it went right back down to
less than 50% capacity (actually a bit worse; after a few dozen of these
cycles, the battery was destroyed).
Now, one thing I didn't try was to apply an external source of heat. The
life shouldn't be shortened as drastically if the heat was not produced
by overcharging.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Equalization switch? What does that do (yeah, I know it's
supposed to "equalize" the batteries, but what specifically does
it do)?
I think it is time (if you haven't already done it) to unscrew
all those little screws on the front of the K&W, find the
resistor, and verify that it is the correct one (the instructions
had a table of resistors and their color coding). I would also
verify that the resistor does indeed have the correct resistance.
If you haven't been inside a K&W before, this is no big deal. If
you don't have the instruction sheet, unfortunately I no longer
have mine, but we can probably find one somewhere in this group
of EV'ers.
If you have a loose cable, enough to cause this problem,
especially a large gauge, high current one, and the car has been
driven, I think you would already know it, as in smoke or
meltdown. Also, a loose cable would mean high resistance, so
your voltage would be higher and/or your current less for
charging.
Hey Lawrence, you've been doing EVs for a long time, and you're a
frequent EVDL contributor. This ought to be chump change for
you. Maybe you haven't worked with K&Ws before?
----- Original Message -----
From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, April 03, 2006 3:21 PM
Subject: Re: 96v charge only goes to 121.5 & 5 amps. Wrong
resistor?
> I never installed the resistor. Danny Ames did. He also
installed an
> equalization switch. Now with the 102vdc eq on it is charging
the pack to
> 124vdc at 5 amps. It won't fall any further. I suspect I need
a different
> resistor. I'm aiming at full voltage and one amp at end of
charge. Could
> also be a loose cable somewhere causing trouble. LR......
> ----- Original Message -----
> From: "Chuck Hursch" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Monday, April 03, 2006 1:23 AM
> Subject: Re: 96v charge only goes to 121.5 & 5 amps. Wrong
resistor?
>
>
> > When I had my K&W BC-20 with a 96V pack of floodeds, if I had
the
> > Voltage knob (I believe it was) cranked full clockwise, I
could
> > see about 4A at 127V or so. I used the 96V resistor per the
> > instructions. Are you sure you are reading the resistors
> > correctly?
> >
> > ----- Original Message -----
> > From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
> > To: "Electric Vehicle Discussion List" <ev@listproc.sjsu.edu>
> > Sent: Thursday, March 30, 2006 9:15 AM
> > Subject: 96v charge only goes to 121.5 & 5 amps. Wrong
resistor?
> >
> >
> >> Got a K&WBC20 in Bob's Curbwatt & it's gassing & lost 5 of
it's
> > 10 charging
> >> amps. It seems to be stalling at 121.5 @ 5 amps. I'd think
it
> > should go to
> >> 124 and the amps drop to near zero. It's a new pack of US
> > 125's @ (96v /16
> >> batteries). The charger is setup with the 102v resistor.
> > Maybe a different
> >> resistor??????(the 108)
> >> Lawrence Rhodes
> >> Bassoon/Contrabassoon
> >> Reedmaker
> >> Book 4/5 doubler
> >> Electric Vehicle & Solar Power Advocate
> >> Vegetable Oil Car.
> >> 415-821-3519
> >> [EMAIL PROTECTED]
> >>
> >
>
--- End Message ---
--- Begin Message ---
Lee Hart wrote Monday, April 03, 2006 6:26 PM:
> Ryan Stotts wrote:
> >
> > Lee Hart wrote:
> >
> > > EV with (say) a 200v pack, the motor will *still* be at 96v
or less most
> > > of the time.
> >
> > Why not 170v?
>
> The point was that a given motor takes a certain voltage to
produce a
> given speed and power. Suppose you're running a 9" motor, rated
at 96
> volts and 190 amps. You can get that voltage with a 96v pack
and a
> controller that is fully on; or from a 192v pack and a
controller
> running at a 50% duty cycle; or from a 170v pack and controller
at
> 96/170=56.5% duty cycle. Motor volts, amps, rpm, and torque are
the same
> in every case.
And then there is the issue that one has to always chime in with,
and that is pack sag. At 100% controller duty cycle at about
350A in and 350A out of the Curtis 1231C controller, my pack of
96V 6V floodies was measuring about 79V, this with only a few
miles on the pack and not much time since the last full charge.
That's about 16V out of 96V, or ~16%, or maybe somewhat more,
since the standing voltage on that pack would be significantly
over 96V, more like 100V.
--- End Message ---
--- Begin Message ---
John Wayland wrote Sunday, April 02, 2006 10:18 PM:
> Electro Automotive wrote:
>
[snip]
> > Here we go again. I've never heard the Curtis squeal except
backing
> > out of a parking space, when it serves nicely as a pedestrian
> > warning. In forward motion, I accelerate through that low
speed
> > squeal too quickly to notice it.
>
>
> Perhaps your hearing is impaired? Review the EVDL archives of
all the
> complaints from EVers, especially those who were embarrassed at
parade
> events, EV car shows, etc. over comments about the noise their
Curtis
> powered EVs made.
Frankly, I don't mind the 1231C's squealing. It goes away
quickly. People have mentioned it in low-speed situations such
as parking lots and carports. But there is a lot of noise out
there in the world, and most people just don't notice it. Maybe
I don't notice it that much, either, with the infernal tinnitis
(ear ringing) I have with allergies from all the lush California
plant growth (read pollen in the Allergy Capitol of the World)
and the noisy world that seems to kick it off even more, and it
seems bad now with all the rain we've been getting lately that
you folks up in WA and OR should be getting. On days when my
ears are settled down and quiet, yeah, I can hear that Cursit,
but even then, frankly, it's not much of an issue for me.
>
> > (Yes, even in my pitiful low voltage, low current car, I can
> > accelerate that quickly!)
>
>
> Prove that, please. Please show data on the 0-60 of your 96V
Rabbit
> conversion. At the sagged voltage under the 500 amps that
squealer
> makes, you've got 40 hp to move 2900 lbs.....yeah, I bet it
really
> hauls! I'd bet you've never, ever, drag raced it on a track
with real
> timing devices. I'll help you out here... My guess, is that it
would
> have a 2.5 second 60 ft., that the 0-60 would take 17-19
seconds, and
> that top speed on level ground might be a real 85 mph, given
several
> miles to get there.
>
> > And as for low performance, I have more often been held back
in a 96V
> > Rabbit by slow gas cars than vice verse. I have even passed
gas cars
> > going uphill....Sweeping generalizations about "most people"
are
> > usually misleading.
>
>
> And you talk about sweeping, generalized statements? This
hardly backs
> up your talk. Try hard facts, please. Try it like this....
>
> The stock 1981 Rabbit weighs 1775 lbs., has 74 hp, and takes
12.6
> l-o-n-g seconds to get to 60 mph. In today's terms when the
average
> economy car does the 0-60 run in 8-9 seconds (even the squeaky
clean
> running 70+ mpg Honda Insight does it in 10.4 seconds), a 13
second 0-60
> time is considered s-l-o-w! Keep in mind, this is for the light
weight
> gas version...I haven't gotten to your 2880 lb. EV conversion
yet.
>
> Now, pull the gas engine out that weighs 220 lbs. and the light
weight
> gas tank and fuel lines and such, and you 'might remove $250
lbs. of
> stuff. Now, put in the ADC 9 inch at 143 lbs., the adapter set
to mate
> it to the tranny at ~ 30 lbs., a controller and braketry at 20
lbs., and
> the brackets and cabling for for all the batteries at around 50
lbs.,
> and you just negated the weight you removed. Now, add in 16, 70
lb.
> batteries and you've added 1120 lbs. to the car. 1775 lbs. +
1120 lbs.
> gets you 2895 lbs. (100 lbs. more than Shari's claimed 2880
lbs.) Now,
> most Rabbits weighed more, as in the 1983 version that weighed
2000
> lbs......2895 lbs. + 225 '1983' extra lbs., and the car now
weighs 3120
> lbs. Gee Shari, sounds an awful lot like my quote "a 96V
Rabbit, a
> small car that unfortunately weighs in at over 3000 converted
lbs."
>
> Let's just round the conversion weight to 2900 lbs. and give
Shari the
> nod here. Shari, again, please give the 0-60 time of a 2900 lb.
car with
> 40 hp to move it, compared to a 1775 lb. car with 74 hp that we
know
> does 0-60 in 12.6 seconds, and that is generally regarded by
all
> automotive testers, experts, and drivers to be very slow in
terms of
> acceleration power.
Want some numbers and driving experience from someone who did a
VoltsRabbit conversion and has lived with one for 11-12 years,
and has filled up several lab books with data and stuff?
1980 Volkswagen Rabbit Diesel with half a tank of fuel and a
functional air conditioner registered 2000 lbs even on the
scales. 65/35 F/R weight distribution, assuming a point just
behind the front seats as the dividing line between the front and
rear, although I doubt where you put the line really matters -
I'd have to draw the physics vector diagrams or talk to somebody
who really knows.
Several months later out the door as an electric VoltsRabbit with
96V pack of 6V floodies (1050 lbs @ ~65lbs each), 8" ADC motor,
RUSSCO heater with fluid in itself and pipes to the heater core,
air conditioner condensor coils over-the-shoulder but evaporative
coils still under the dash, cut down fly-wheel registered 2940
lbs on the same scales, and 60/40 F/R weight distribution. I
suspect the car is a few tens of pounds heavier now since I've
added wiring for the hoped-for BMS system (someday...) and some
other little goodies. On the other hand, I have lopped off a few
pounds by using a smaller auxiliary battery. Front seats are
33lbs apiece (my eyes nearly popped when I measured this, but
yeah, they are a grunt to get out), and I'd like to get lighter
seats, and do occasionally run with just one front seat. Steel
13"x5" wheels at 15lbs apiece (as compared to 8lbs for the
EV1's)... but I digress...
Aside from the EV having one heck of a lot less vibration and
running a whole lot smoother than the diesel (which itself ran
well for a Rabbit Diesel - it could nail 50mpg on the highway w/o
much trouble or smoke), subjective experiences are:
1) The EV VoltsRabbit (with 1231C upgrade) is definitely faster
off the line, and is, in fact, a good match for most any normal
ICE car if you want to see who gets to the cross-walk lines on
the other side of the intersection first. Diesels are slow off
the line, but once they get rolling, they are rather amazing -
they just keep coming. My EV's performance was certainly helped
but upgrading from a 1221B controller to a 1231C after the
former's failure in one year of driving in this hilly territory.
2) The EV VoltsRabbit is certainly slower going up freeway hills
than the diesel. Take the Hi101 Waldo Grade down south to go
over the Golden Gate Bridge into San Francisco. The diesel would
do this at the speed limit (55mph) or better as I recall, without
much trouble. The EV VoltsRabbit, not a chance. About 35mph in
2nd gear, although I once just barely managed it at about 42mph
hanging out at high motor amps in 3rd gear. Do I do this with
regularity? No. It's easier on the car to take the surface
streets down in Sausalito, and frankly, I just don't go into SF
much anymore.
3) Top speed: 70-75 mph. If it had a 5th gear, it could
probably do about 80-85mph, as one very similar car owned by a
long-time EV'er over in the East Bay did on a stretch of freeway.
That's probably what the diesel would do.
Somewhere in this thread, there was mention of hot motors. I've
never really had much of a hot motor problem. The 8" ADC has
always stayed cool enough so that I could put my hands on the
case and leave them there, even on 100-deg days and being on a
freeway and coming back home up my hill. Putting said hand on
one of the cable-connection brush bolts would be a little tougher
to keep there, but could still be done with a little chutzpah.
Now that I have a front bellypan on most of the time, and have
added a case temperature sensor, the motor will run say 10-20
degrees hotter, depending on how far I go or how warm it is
outside, and the terrain. But during the winter, and even in the
summer, on my 5-mile (one-way) drive to work over a short freeway
grade, the motor usually sees at most 120-130 degF at the case
sensor. I can actually run 20-25 miles with the bellypan on
during mild days on those rare freeway runs, and the case
temperature will stay at 150 or less. (Otmar told me 150-degF is
as high as I should let it go.)
And here's a 1/4-mile run in a parking lot at a former naval
yard, rather impromptu, but probably fairly close to what I could
get on a dragstrip. Two people in the car, one driving, one
timing. 25-26 seconds @ ~50mph. At a dragstrip with one person
in the car, I suspect 24 sec @ maybe a bit better than 50mph.
Yeah, that's slow, winding out through the gears is slow... So,
letting the laughter die down...
Yeah, you gotta see what she'll do. But here's the punch line:
does all that "slowness" really matter? No, not really. I've
found this car to be a very useful tool for getting 'round town
with limited freeway driving. It gets me to work everyday, to
the stores and various other shops when the need arises, and gets
me home up my dang steep hill everytime, come pouring rain or
100-deg broiling sun in the long dry summers. And frankly, the
car drives quite well in traffic - I don't have much to complain
about as long as I stay off long steep freeway grades. The
VoltsRabbit kit enabled me to build my own car with my own hands,
tools and some help, and that's worth something everytime I hop
in the car to go somewhere, and should, with a modicum of luck,
put me in a much better situation skill-wise to dove-tail the EV
in with an off-the-grid RE home somewhere quiet out in the
country that will let my ring-y ears rest.
All that said, and there really is a lot more, to close this,
yes, John, I do like hi-perf cars and applaud what you, et.al.
are doing - pushing the envelope. I would love to get a ride in
an EV as it pushes me back in the seat with electric torque doing
0-60 in under 6sec. In my late teens, I had stacks and stacks of
Hot Rod mags and others, and I read of all the tricks to soup up
motors. A big wide Chrysler Hemi 426 with nearly 9"-wide valve
covers peering at me out of those magazine pages would certainly
demand my attention, and still does, to some degree. I even had
a souped-up Chevy Malibu with 350cid 4-barrel, dual exhaust that
would clear 90mph by the end of a freeway on-ramp, and 100mph was
close behind. Technology improves, with econo-car #s being
rather amazing. But do I really need all that, with techno creep
making each year's model a bit better than last (a great "keep up
with Jones'" sales ploy)? - No!! To get where I want to go
nowadays, the Yellow Banana (the name of my car) gets me most of
where I need to go just fine!
Chuck
Chuck Hursch
Larkspur, CA
http://www.austinev.org/evalbum/339.html
http://www.geocities.com/chursch/bizcard.bmp
--- End Message ---
--- Begin Message ---
Mark Freidberg [mailto:[EMAIL PROTECTED] wrote:
> How would I tell if they are "premade?" The 2 AWG cables
> read "Cobra Wire & Cable, Inc. E51293"
A quick web search turns this up as marine battery cable (i.e. tinned
strands), but does not clarify if your interconnects might have been
bought premade or not. Premade or not, your best bet is to measure the
voltage drop while running some known current through them; if the
voltage drop is low enough, then they are fine.
> What about this idea? Just double them up, 2 per
> interconnection instead of 1. If I specified flag terminals,
> I could place one lug on each side of the terminal.
Sure, you could do this, if you have enough cables. In the grand scheme
of things, cable and terminals are pretty cheap items, and I personally
would not attempt to reuse cables from some other system just to save
the $100-150 associated with making up a proper set that fits *my*
system.
It is unlikely that the premade cables are the right lengths for your
installation, so you will end up with cables that are just a bit too
short or a somewhat too long; either the cable is stressed by being
tight, or it may have excess length flopping about that could cause you
grief eventually.
If you go with paralleled cables, you can never be sure how the current
will divide between them, so it is always a bit riskier than using a
single appropriately sized cable (though the risk may still be small in
your case).
> When I had eight 39ah Hawkers temporarily connected they
> were good for 4 miles in my hill-plentiful neighborhood and
> the amp draws peaked out around 217 amps during brief climbs.
> Nothing was warm afterwards except a single 4 ft. long 4 AWG
> cable connection..
If your peak amp draws really are this low, then you might well get by
with using a single set of the #2 cables. However, unless you have a
very light vehicle and/or a very wimpy controller, you will likely find
that you sustain current draws of a couple hundred amps for a fair time
climbing longer hills or holding speed on a grade for a mile or two. I
wouldn't use cables like this in anything heavier than a NEV (about
1500lbs) unless I was running fairly high voltage, but if it works for
you in your application and you don't mind the look, go for it.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Your project sounds great please keep us upgraded on the final results.
Lawrence Rhodes......
----- Original Message -----
From: "Peter Perkins" <[EMAIL PROTECTED]>
To: "'Steve O'" <[EMAIL PROTECTED]>; "'David Young'"
<[EMAIL PROTECTED]>; "'Evan Tuer'" <[EMAIL PROTECTED]>;
"'Jim Fell'" <[EMAIL PROTECTED]>; "'Harry Simmonds'"
<[EMAIL PROTECTED]>; <ev@listproc.sjsu.edu>
Sent: Thursday, April 06, 2006 6:41 AM
Subject: Finally back on the road. AC Li-ion upgrade (Long)
Dear All
After a false start due to propshaft problem, finally back on the road
today.
Just been on a gentle 10 mile trip. Sweet as a nut. Smooth and silent.
Final
AC controller tweaking and should be OK.
Need to travel to a couple of hills for some regen testing.
Better update my web site now.
Regards
Peter UK
Old update and pics below.
Dear List Members.
It works!
The wheels go round! And the right way. Well they do now, after I swaped
the
motor connections, and corrected one wiring mistake on the throttle pot!
Initial one mile road test thoughts,
1) Much improved acceleration and start ability.
2) Regeneration! Great, not had that before :)
3) Quieter at crusing speed. Only road/tyre/wind noise now.
Cedric Lynch Li-Ion cell protectors all ok.
Modified Zivan 3kw 25A IUa NG3 onboard charger functioning ok
Home made 6kw 55A offboard charger functioning ok.
Battery heater ok, temp 20C.
Vehicle is now on charge, receiving a CV balancing charge for a few hours,
probably overnight, TS 200ah cells have been stood for 4-5 months. Inter
cell voltage variation <75mv.
28 cells, pack voltage is steady at 117v and current is slowly falling.
Less
than 4A now.
A bit more fiddling to do (A project like this is never finished really!),
and some adjustments to AC controller parameters to make.
I'll pass on performance tests asap.
PS
I have a Zapi programming console now, if anyone in the UK ever needs to
borrow one.
Peter
www.solarvan.co.uk
See below for old update and pics/specs
Dear Members
Some of you will know I am doing a low cost, low voltage DC to AC upgrade
at
present. (New information and progress report is at the bottom of this
mail)
I will soon be running a 96v 450A Zapi 3phase ac controller with regen and
a
96v 3phase 12kw con rated induction motor.
The motor and controller cost me £2000 brand new.
I am lucky enough to own a pack of 200Ah TS cells and can report good life
and performance in the 2+ years I have had them.
A few links for interest are here.
http://www.electrofit-zapi.com/hfacinverters.htm
www.solarvan.co.uk
The motor came from Best Motors in Italy.
http://www.bestmotor.it/frameset_ei.html
They do not list AC motors on the site, but do supply them to order and
spec.
Zapi only supply a controller with a motor, as they require matching.
That's
why I ended up with an Italian motor as well.
Curtis operate the same policy I think. You will be lucky if they sell you
a
controller without a motor.
I went for the Zapi controller as it allowed a higher voltage 96v instead
of
the curtis 80v.
A couple of pics of the motor/controller versus my old 120v 400A curtis
stuff are here, as are motor spec drawing, motor torque voltage curves and
Zapi AC controller manual.
www.solarvan.co.uk/ac017.jpg
www.solarvan.co.uk/ac021.jpg
www.solarvan.co.uk/bestmotor.pdf
www.solarvan.co.uk/ac3manual.pdf
www.solarvan.co.uk/MVC-001F.jpg
www.solarvan.co.uk/MVC-002F.jpg
www.solarvan.co.uk/MVC-003F.jpg
www.solarvan.co.uk/MVC-004F.jpg
www.solarvan.co.uk/MVC-005F.jpg
Hope to get upgrade finished by 010406
New for 04/02/06 are ten more pictures of my current progress.
They are at www.solarvan.co.uk/ac01.jpg to www.solarvan.co.uk/ac10.jpg
inclusive. Just change the number to get the other pictures. They are
about
350kb each to give full detail.
My TS Cells are now contained in a false floor battery and insulation
layer
cake inside the vehicle. They are securely strapped down with that 12mm
300kg breaking strain nylon packing tape, tensioned and crimped, two
straps
per cell to about 100kg each. I have a full set of crimping, tensioning
tools, crimps and miles of tape if anyone wants to borrow it in UK. It was
excellent for securing and compressing cells. Fits perefectly into slots
in
TS cells.
Basically the floor is raised about 6 inches now.
It's layered as follows.
1st layer, onto original van metal floor, 25mm Kingspan silvered
insulation.
2nd layer, 9mm plywood sheet drilled and bolted through insulation and
metal
vehicle floor, drilled and fitted with 12mm strapping before placing in
vehicle.
3rd layer, 28x200ah TS Cells laid out as you see, and securely strapped
down, with white electric blanket heating wire underneath all cells to
keep
them warm.
Note, sides also filled with blocks of Kingspan insulation to make a
sealed
compartment.
4th layer, sheet of 2mm ultra lightweight compressible foam to seal gaps
between edges and top sheet of thermo insulation, and to provide
electrical
insulation between silvered side of thermo insulation and cells. Well you
never know, a loose wire can occur!
5th layer, another sheet of 25mm Kingspan silvered insulation.
6th layer, a sheet of 12mm plywood to provide load flooring, bolted
through
layers to vehicle metal body.
7th layer, Carpet! Not yet fitted as you see.
I was happy to sacrifice some load space to allow the secure and insulated
fitting of the most expensive item, the battery pack!
The under cell mains powered heating is thermostat controlled, and shuts
off
when cells reach 25C.
I have left provision for forced air ventilation through cells if
required,
but I will monitor pack temp and see if I actually need to fit this!
The ambient temp is quite low here in Northern England, I don't envisage
overheating will be a major problem.
The underseat electronics compartment is coming along well. It's still
wires
all over the place at the moment, but I'm pretty pleased with progress.
The AC motor is now in situ underneath the vehicle on a very secure mild
steel mounting as you can see.
My ETA of 01/04/06 looks quite acheivable at present.
I will update my website when it's finally done.
Regards
Peter Perkins.
Chilly in the UK!
--
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--- End Message ---
--- Begin Message ---
Doug Weathers [mailto:[EMAIL PROTECTED] wrote:
> That appears to be a Curtis DC/DC converter for EVs.
>
>
<http://www.curtisinst.com/index.cfm?fuseaction=cProducts.dspProductCate
gory&catID=16>
>
> 24v to 96v input, 375w output.
Be wary of operating this DC/DC with a pack at the upper end of its
ratings. I don't know about the other input voltage models, but the
72/96 input model *cannot* tolerate the voltage of a 96V lead acid pack
at the end of charge.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Peter wrote:
> Cutting the RPM by 20% might cause a 100% increase in current draw,
> at a given voltage.
True, but this has nothing to do with the torque/RPM curve.
It is a result of the "back-EMF" of the spinning motor, as
the current is a result of the *difference* between back-EMF
and battery voltage. That is why upshifting is needed and
gives you more power (within limits) on an EV.
The back-EMF is roughly lineair with the RPMs.
A theoretical example:
- battery voltage 100V
- motor running 4000 RPM in 2nd gear with back-EMF 80V
- motor running 3000 RPM in 3rd gear with back-EMF 60V
- motor resistance 0.2 Ohms
- all other (internal) resistances ignored for simplicity
In 2nd gear the motor draws 100 Amp (100V - 80V = 20V divided by 0.2 Ohms)
In 3rd gear the motor draws 200 Amp (100V - 60V = 40V divided by 0.2 Ohms)
Since the voltage delivered to the motor is 100V in both cases, the power
goes from 10kW to 20kW by upshifting from 2nd to 3rd, reducing RPM by 25%.
NOTE that the *torque* does not double, because the gearing has changed,
so for hill-climbing there is a limit to the benefit of upshifting.
But certainly going on a freeway and attaining higher speeds is only
working by upshifting to increase the motor power.
Hope this clarifies,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Peter VanDerWal
Sent: Thursday, April 06, 2006 10:23 AM
To: ev@listproc.sjsu.edu
Subject: Re: Motor options
> This always puzzled me:
>
> Lee Hart wrote:
>
>> If you want more horsepower (for climbing a hill or accellerating), a
>> 96v pack only gives you one choice; upshift (like from 2nd to 3rd gear).
>> Note that this is the *opposite* of what you'd do with an ICE.
>> Upshifting slows the motor down, which makes it draw more current. For
>> 2x the horsepower, you need 2x the current; 96v at 380 amps.
>
> No, Lee, I think this is not correct. The power is torque * RPM,
> and torque is current (~linear dependency), so when you upshift you
> cause motor to draw twice as much current (produce twice torque)
> but multiplied by half as much RPM now, it still totals the same power.
>
Except that shifting from 2nd to 3rd does NOT cut your RPM in half, at
least not on any transmission I've seen.
It might double your current though, because series wound motors don't
have a linear torque to RPM curve (that's why it's called a curve, it
bends).
Cutting the RPM by 20% might cause a 100% increase in current draw, at a
given voltage.
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
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wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
IMHO, Jeff has a good answer: Propane, which runs much cleaner than gasoline.
http://www.epa.gov/otaq/consumer/fuels/altfuels/420f00039.pdf
Propane conversion is my EVentual plan for the aircooled VW engine that will be
reincarnated as a long ranger for the Karmann Eclectric. Not only will the
engine run very cleanly and have reduced maintenance requirements, the old VW
sewing machine will also produce plenty more power than even a mighty PFC 50
could transmit to the pack.
See if I've made a leap of math here...
At 60 mph pulling a trailer, I'll allow a hoggish 250 w/h per mile for the Ghia
combo. That's 15 kW, only 1/3 the peak power of a 1600cc VW flat four. This
would be easily supplied by a 20kw generator head, but I'd have to bypass the
PFC with a Big Bad Boy on my 240 VDC system, or upgrade to a "PFC 70 " (70 amps
in at 220 VAC= 15.4 kW).
Fuel consumption would be @ 25% worse on propane, I figure 2.5 gallons/hour
instead of 2 (the Ghia reliably got over 30 mpg on the highway). That would
still give a 4 hr run time on one 40 lb (10 gal) cylinder.
Eh? -Jay
www.karmanneclectric.blogspot.com
--- End Message ---
--- Begin Message ---
Mike,
The friend that did my box would be happy to make another one
to carry the 4 additional batteries for your truck.
Someone else told me that there is a version of the UB121100
that does not have flag-terminals but the bolt-in version.
That could theoretically make all 26 x 110 AH batteries fit
in the original box, but there will be hardly room to run
cables, most likely you will need to use copper strip to
be able to stack batteries less than 1/4" close to each other.
Let me know if you want to explore this further.
Regards,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Mike Phillips
Sent: Thursday, April 06, 2006 7:35 AM
To: ev@listproc.sjsu.edu
Subject: RE: Battery Pack Heating
Trust me, 4 strings was so NOT my idea. That's how I got the truck.
It's bad. I spot tested a few Hawkers last night. Even the new ones
that were 16 minutes at 40 amps are now 13 minute batterys. There could
be a temperature curve in there. But the older batts went from 10
minutes at 40 amps to 3-4 minutes last night.
As much as I hate doing the work, maybe adding another box and going
for the 100ah batts would simplify things after th einitial
installation shock.
Mike
--- Cor van de Water <[EMAIL PROTECTED]> wrote:
> Mike,
>
> Don't lose the truck,
> just make sure that all your strings have equal
> internal resistance (so they share load) or aim
> for a single string next time,
> that way you lose more than half the problem. (IMHO)
>
> Cor van de Water
> Systems Architect
> Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
> Skype: cor_van_de_water IM: [EMAIL PROTECTED]
> Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
> Fax: +1 408 731 3675 eFAX: +31-87-784-1130
> Proxim Wireless Networks eFAX: +1-610-423-5743
> Take your network further http://www.proxim.com
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]
> Behalf Of Mike Phillips
> Sent: Wednesday, April 05, 2006 5:08 PM
> To: Roger Stockton
> Subject: Re: Battery Pack Heating
>
>
> There may be more, but ACP had Alan's orginal CRX with batterys
> inside
> the car like most converted ev's. Then they built at least two more
> Hondas. One of which is a CRX the other is just slightly larger but
> still a two door version. Then there is the Saturn as well. I've lost
> track of the Tzeros as most have been sold. They still had a lead
> acid
> car down there. I know one Lion Tzero car that is up here around
> Silicon Valley somewhere.
>
> Typical is 220 wh/mi with no kindness to acceleration. I promise this
> is a 14 second car.
>
> If heating was not germaine to the packs life, ACP would not have
> kept
> putting it in their lead acid cars.
>
> One of the ACP owner/drivers doesn't watch for DOD at all. He drives
> his car until the monitoring system shows 11 volts per battery under
> light load. Which is about 40-50 amps in these cars. He gets 20-30k
> from a pack in his daily driver. He has told me that getting 20-30k
> is
> routine in their cars.
>
> These guys plus the NREL report are enough proof for me to
> investigate
> and build thermal management into my truck. Maybe having Optimas is
> the magic ingredient, but I have to do something constructive as 5k
> miles per pack makes a 440 powered Chrysler look cheap to drive. That
> is providing that I don't sell the truck first ;)
>
> Mike
>
>
>
>
>
>
>
> --- In [EMAIL PROTECTED], "Roger Stockton" <[EMAIL PROTECTED]>
> wrote:
> >
> > Mike Phillips [mailto:[EMAIL PROTECTED] wrote:
> >
> > > 150 wh/mi is at very low speed on level ground. It's not
> > > what a typical user generates in daily driving. This is
> > > what I have observed riding in these cars.
> >
> > So which "cars" are you referring to? Alan's original (and only?)
> CRX
> > running Optimas or one or more Tzero's running Optimas? I thought
> there
> > were only a couple Tzeros built and that at least one of them is
> running
> > a near-7000 cell Li pack, not lead-acid.
> >
> > If 150Wh/mi is not typical, what have you observed to be typical in
> > these cars?
> >
> > > These are the weekly clues I get that tell me ACP's
> > > battery management has great merit in making battery
> > > life all it can be.
> >
> > I'm a great believer in BMS. You have provided nothing to suggest
> to me
> > that heating the batteries does anything to improve battery life in
> a
> > cyclic application. My belief is that those who operate their
> batteries
> > at elevated temperatures do so to achieve the absolute greatest
> range
> > per charge, and that a good BMS may allow them to still achieve a
> decent
> > life *despite* the detrimental effects of elevated temperature on
> the
> > battery internals.
> >
> > > I'd like to see what lead acid Ranger and EV1 owners use to get
> from a
> > > pack in terms of cycle life.
> >
> > There is no such thing as an EV1 owner; EV1's were leased, and I
> doubt
> > anyone will ever know what the true battery life was since the
> factory
> > service could include anything from swapping out weak modules
> before the
> > leasee ever noticed them to swapping out the entire pack, without
> the
> > user being any the wiser.
> >
> > > What kind of EV do you own Roger?
> >
> > Not sure why that is relevant, but mine is a 120V Suzuki Forsa
> (Chevy
> > Sprint) conversion presently loaded with YTs. I suppose I should
> be
> > cheering you on to go ahead and cook a set of YTs so the rest of us
> can
> > learn on your dime what to do with our packs ;^>, but I can't help
> but
> > caution you when everything we know about lead acid batteries
> suggests
> > that elevated temperatures are at odds with maximising battery
> life.
> >
> > Cheers,
> >
> > Roger.
> >
>
>
>
>
>
Here's to the crazy ones.
The misfits.
The rebels.
The troublemakers.
The round pegs in the square holes.
The ones who see things differently
The ones that change the world!!
www.RotorDesign.com
--- End Message ---
--- Begin Message ---
The other option is to put in as many agm's as possible & spend your money
on the biggest charger you can or two of them. There are some people that
can do 100 miles with one one hour charge. That might work better. It's
not the range it's the charging time that is the problem. Lawrence........
----- Original Message -----
From: "Robert Baertsch" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, April 06, 2006 12:00 PM
Subject: Re: 80 miles in a Porsche 911?
It is a 1980 Targa 911 SC. The suspension in the back is quite adjustable
so that would be fine. I'm concerned about the front suspension which is
not designed for a heavy load.
The ride is already very hard and I'm not sure what will happen when I
load it up.
I think Lithiums would cost over $10K so I'm going to wait until my first
set of AGMs wear out for advanced chemistry. I think batteries will be
much better is 3-4 years.
There is a Toyota Pickup (2500lbs stock/5260lbs converted) on the evalbum
with 40 T105 Trogan (6v 225ah) batteries that claims over 120 highway
miles. http://www.austinev.org/evalbum/037.html
Besides I already have 27 12v 110ah AGM sitting in my garage waiting for a
donor. I don't think the Orbitals have that much capacity. If I used
Tony's truck platform with my batteries I should get over 100 miles.
Am I missing something?
To answer Larry's question, I'm looking for 60mph highway speeds for most
of the trip.
-Robert
David Dymaxion wrote:
Not really an expert, but I'm converting one myself. What year is
your donor car?
Compare to some other cars: The super efficient EV1 with roughly 50%
weight in batteries would go about 40 to 60 miles on a charge (1st
gen lead acid batteries) and about 60 to 80 miles on the 2nd gen lead
acid batteries. Real featherfooting and low speeds would get it 100
miles. The Tzero by AC Propulsion claimed a 100 mile range on lead
acid batteries -- but this is a car with no doors, no transmission,
and an expensive AC drive system.
I'd think 80 miles on lead acid batteries is going to be tough. It
would be much easier with advanced chemistry.
Having said that, with 1900 lbs of batteries and a 911, you might
have a shot at it. The 911 is light and the gas motor is heavy. The
aerodynamics are good, it goes surprisingly fast on modest
horsepower. The suspension is fully adjustable, so you can optimize
toe on both axles. You can get race seats, fiberglass bumpers, and
plastic windows and shave off some weight. You could also put on a
belly pan and shave the rain gutters to improve the aerodynamics.
On the flip side, the truck's aero is going to stink, so you'd need
alot of batteries to get it to work.
My guess is it would boil down to the 911 is better for highway work,
and the truck is better for low speed work.
Final thought: This might be a case for a hybrid pack. Do 26
Orbitals, and as many Lithium batteries as you can afford. Have the
Lithium batteries give a steady 50 amps or so to charge the lead
batteries, and the lead handles the high current bursts. You'd be on
your own here, though, as you'd be trailblazing.
--- Robert Baertsch <[EMAIL PROTECTED]> wrote:
I would really like to get 80 miles in the Porsche 911 and I could
fit 26 110ah AGM batteries inside.
Looks like 8 in the gas tank area, 6 across the back seat, 2 on the
floor and 10 in the engine compartment.
The battery weight would be 27x72lbs=1944lbs. I think the awesome
porsche handling will go out the window with a final weight over
3800lbs. I'm now thinking of the small light pickup instead. The
extra weight should be easier to deal with.
Any Porsche experts out there? I hate to sell this car.
__________________________________________________
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--- End Message ---
--- Begin Message ---
Here is a nice web page all about EV pushers
http://www.mrsharkey.com/pusher.htm
Having the trailer push is not a big deal. It is like
putting on the car brakes with a trailer that has no brakes. No big
deal as far as handling goes. The EV greatly outweighs the pusher.
How cleverly you integrate the throttle determines how
seamless the driving would be. If you do a good job there, you would
not even notice it was behind you on the highway.
Backing up a small trailer takes some practice. That would
be the hardest part to get used to.
If you run the pusher on biodiesel you are polluting
significantly less than you would be running a gasoline car. Small
generators pollute MUCH more than car engines do, so a biodiesel
pusher seems the best solution to get an EV from one city to another.
Bill Dube'
At 12:16 PM 4/6/2006, you wrote:
Bill,
what type of dynamic stability issues might arise with a pusher
trailer? Are there any mechanical design pitfalls in the trailer
hitch pusher connection arm, etc. that should be taken into account
to make the pusher design safe and easy to manage when driving?
If I build one of these with a rabbit diesel front clip, my wife
would need to be able to drive with it.
Paul Wallace
'91 Chevy S-10 full of SAFT nicads
Following messagee from Bill Dube:
------------------------------------------------------
Adding a generator makes the EV an ICE car. You must then pass
emissions, just like any other hybrid.
If you do the math, you will discover that you need a 10 to 20 kW
generator. This is neither small nor inexpensive.
You can make a very nice pusher from a front clip of a wrecked car
for under $2000.
You can share a pusher with other EVs, but it is difficult to find a
spot on a converted car to put a 20 kW generator and its fuel tank.
You can very easily connect the pusher only when you need it, and
disconnect it whenever you don't need it. It is not so easy to
remove and replace a 20 kW generator.
A pusher is a well-proven approach to a "convertible" hybrid.
Bill Dube'
At 05:46 AM 4/6/2006, you wrote:
> Danny wrote:
>
>> A Porshe 911 with half a VW bug behind it... hilarious!
>>
>> But seriously, the dynamics of such a trailer look incredibly
dangerous. I know I've never driven one, but the flaws are frankly
quite obvious. I don't doubt that it can go in a straight line
with a skilled driver, but there are very serious handling issues
involved in pushing a vehicle like this!
>
>
> Actually, I don't think the flaws are quite so obvious. I can't
see how the dynamics of being pushed by a trailer driven by an
engine are any different from the dynamics of being pushed by a
trailer being driven downhill by gravity, except you can control
the engine but cannot control gravity. Consider also that the
combined EV/pusher combo is actually simply an articulated rear
wheel drive vehicle. Some articulated buses are built this
way. They seem to work.
>
> The other side of question is the purpose of the unit. If the
idea is to simply transport passengers and cargo from point a to
point b, then it is certainly likely to be more efficient from the
energy use standpoint to use a conventional ICE car instead. On
the other hand, if the point is to transport the EV to a spot
outside it's conventional range, then you should be comparing the
energy used by the EV pusher combo to that of a truck towing a
trailer with the EV on it. Under those conditions the efficiency
equation probably looks quite different.
>
> Our EV club often get requests to display EVs at events 100 to
200 miles away. With no existing public charging facilities within
500 miles or so, getting there is impractical. There is nothing I
dislike more than seeing an EV display and a line of large ICE
pickup trucks and trailers lurking over at the other end of the
parking lot to haul the EVs home again after the event. I just
don't like trailer queens. I also don't want to own, maintain, and
register a big ICE truck just for this kind of thing. Even renting
is not my idea of a good option. Using a pusher trailer or a
generator trailer seems a much more honest and practical solution.
>
> If I were doing another conversion today, I think I would likely
plan on including an on-board generator. Perhaps something o the
order of a small car engine spinning a large AC motor hooked up as
a generator. Of course, to carry all this and an EV drivetrain as
well, the donor would have to be quite sizeable, probably something
on the order of an S-10 or even a full size pickup or SUV.
>
> I do suspect that there may be smaller engines out there, like
say the water cooled Honda RV generators, that could be made as
clean and efficient as a conventional ICE car engine. Anyone feel
clever enough to add fuel injection, a catalytic converter and a
closed loop computer control system to one? At the rate they are
going I wouldn't be all that surprised if Honda didn't do it them
selves before too long.
>
> Thanks,
>
> Mike Chancey,
> '88 Civic EV
> Kansas City, Missouri
> EV List Photo Album at: http://evalbum.com
> My Electric Car at: http://www.geocities.com/electric_honda
> Mid-America EAA chapter at: http://maeaa.org
> Join the EV List at: http://www.madkatz.com/ev/evlist.html
>
> In medio stat virtus - Virtue is in the moderate, not the extreme
position. (Horace)
--- End Message ---
