EV Digest 5325
Topics covered in this issue include:
1) Re: EV Performance
by "Ryan Stotts" <[EMAIL PROTECTED]>
2) RE: 3kw genset for $315
by "Hacker Joel-QA6240" <[EMAIL PROTECTED]>
3) Re: Multi charger.
by Victor Tikhonov <[EMAIL PROTECTED]>
4) Re: Testing for Isolation
by Victor Tikhonov <[EMAIL PROTECTED]>
5) 80 miles in a Porsche 911?
by David Dymaxion <[EMAIL PROTECTED]>
6) RE: 3kw genset for $315
by Cor van de Water <[EMAIL PROTECTED]>
7) Re: Porsche 911 Was: How many amps driving my EV?
by Robert Baertsch <[EMAIL PROTECTED]>
8) RE: How many amps driving my EV?
by Cor van de Water <[EMAIL PROTECTED]>
9) Re: Porsche 911 Was: How many amps driving my EV?
by David Dymaxion <[EMAIL PROTECTED]>
10) Re: EV Performance
by "Roland Wiench" <[EMAIL PROTECTED]>
11) Re: Porsche 911 Was: How many amps driving my EV?
by Danny Miller <[EMAIL PROTECTED]>
12) Re: 3kw genset for $315
by Danny Miller <[EMAIL PROTECTED]>
13) Re: Testing for Isolation
by Lee Hart <[EMAIL PROTECTED]>
14) Pusher trailers, (was Re: Porsche 911 Was: How many amps
driving my EV?)
by Mike Chancey <[EMAIL PROTECTED]>
15) Re: 3kw genset for $315
by Mike Chancey <[EMAIL PROTECTED]>
16) Battery-question
by Pascal <[EMAIL PROTECTED]>
17) ev list
by robert phelps <[EMAIL PROTECTED]>
18) Re: Battery-question
by James Massey <[EMAIL PROTECTED]>
--- Begin Message ---
On 4/5/06, Jeff Shanab <[EMAIL PROTECTED]> wrote:
> In the first 1/2 of the throttle it feels like the pack is almost dead,
> hooked up then continued, it seemed as if the acceleration curve had a
> flat
Sounds like a worn pot box to me. Hook it up to a meter and slowly
move it through it's range and see if the numbers on the meter
increase or decrease in a smooth and linear manner.
--- End Message ---
--- Begin Message ---
3KW is not much power when you figure 200-400Wh/Mile.
Also, did you notice at the bottom of the page - $200 to ship the
thing???
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of bruce parmenter
Sent: Wednesday, April 05, 2006 10:43 PM
To: evlist
Subject: 3kw genset for $315
An ad on one of the discount-store fliers mixed in with the weekly
junk-mail has a 100 lb generator rated at 3000 watts for $315 including
tax.
I will have to go to the store and see what I would be buying but the
small picture shows only a dual 110VAC 20 amp out and a
12 VDC terminals. The genset looks like:
http://www.centralonlinesales.com/show_Product.asp?ID=1616
I could mount it on the tire rack that I have on the rear of my S-10
Blazer. I may also want to mount a jerry can for extra fuel.
-First I am wondering if this generator is one of the types that was
POSTed as a PFC killer?
Since at some point (a year of more) I may have to move to where the
rent is affordable, and where there is no public EV charging, I may need
to use the generator mounted on the back of my EV to get back home.
The odd part is the rating. If the 12 VDC output is 10 amps, that is .12
Kw. And the 110 VAC duplex outlet is likely connected to the same 20 amp
breaker which is 2.2 Kw. That is a total of 2.32Kw. What about the other
.68Kw?
Running my PFC-30 off a 20 amp 110 VAC outlet will not use all its
capabilities, but the lower charge current is offset by the lighter
genset weight. Mounting it on the tire rack means I do not have to have
a trailer. That reduces both weight and drag.
Any views on this topic are welcome.
Bruce {EVangel} Parmenter
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--- End Message ---
--- Begin Message ---
Rich Rudman wrote:
Umm Victor
You keep saying you don't need fast charging
I Don't but I know I'm alone here.
I keep getting large checks to make Hyper fast industrial level chargers.
Clearly my order book and your point of View don't agree.
They don't have to agree Rich, you just have to agree with your order
book and enjoy large checks, I'm happy for you. I only pointed out
there is other camp out there.
My folks don't want to wait.. it costs them money to have equipment not in
operation.
And I have spent way too much of the last 14 years of my life waiting for My
EVs to charge. Now I don't have to.
Again, congrats. If you recall, I have your PFC too, just can't use it
as is with what I do.
Clearly if you have all night to charge your EV.. then you don't need 10s
of Kw worth of charge path.
When we have 100 mile ranges and can store 20, to 40 Kw of power in our
EVs... the over night thing gets back to Getting the job done with the
least power available. 40 Kwhr in 8 hours is still 5Kw into the pack.
Our EV industry didn't have affordable PFC charger that could make more than
a couple of Kw before I got here.
I know, good for you, no need to brag so hard :-)
What I see is much more Stored power... and Range, Powers of magnitude from
what a 1000 lbs of lead can store. This makes Evs much more useable to the
public, And then they want them charges over night for a 100 to 300 mile
range in the morning... this IS going to take some serious levels of
recahrge.
Clearly if I'd plan to drive 300 miles daily and use 40 kWh daily,
I'd be looking for 10 kW or so recharging power. But I drive perhaps
50 miles at most, that's 10kWh. So any 2kW charger gets job done
in 5 hours, putting 50 miles in the pack.
Again, you spent 14 years dealing with lead and still do, and I
didn't (and never will). Requirements are very different, but don't
get me wrong - I clearly see the need out there for fast charging
(as a make up for smallish packs), so glad people has options.
I suppose if you drive 5 miles a day at 45 mph... you could survive with
only 2400 watts over night.
Misrepresenting, you know better Rich. 2400 watts over 8 hours is
19.5kWh total which is 96 miles at very average 200Wh/mile.
So for 100 miles daily from simple 120VAC outlet even PFC20 is
overkill. I know you want to convince everyone they can't survive
without your product, but please play fair.
I get 4 or 5 runs in a day even with a paltry 15 mile range... I have a
usefull EV.
You're trying to make your product look better by making someone else's
look worse than it is in reality. Not a good PR.
OK, 5 runs * 15 miles is 75 miles. With 200Wh/mile EV with only
2.4 kW charger you're done in (0.2kWh/mi * 75 mi) / 2.4kW = 6.25 hours.
If you don't sleep at least 6.25 hours daily, you have issues then,
but most people sleep longer.
Again, I don't take OEM or business customers as taxi operating 24/7 or
such. They are the ones who'd need fast charging badly.
So... there are solid reasons for chargers that draw more than a hair dryer
can....
Sure. There are also reasons not to have them. Your PFC chargers are
wonderful, but I wouldn't take one today even for free - sorry, they are
useless *for me*. Aside that they don't work with anything other than
lead. And, yes, I do have useful EV with more than 5 miles
range at 45 mph. You're the one who test drove it on I205 while I sat on
the pack with no passenger seat installed, remember?
And folks are still paying for them.
Money shmoney :-) I already told you why I wouldn't take it for free.
How would I use it with lithium? Or NiMH?
Why is it so hard to accept that something you make and proud of
may be useless for someone else and other chargers just work better?
Your chargers are just wrong hardware for some application (like mine),
it's not a personal attack! That's only my point.
Rich Rudman
Manzanita Micro
Victor
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
The theory is that a common fault would be a short to ground somewhere
in the battery pack. So, you create such a fault (with a resistor, so
you don't literally have a short and so won't harm anything). If the
Siemens inverter includes ground fault protection, then it should detect
the resistive short to ground.
How??
Unless yo have sensitive current sensors in the pack positive
and pack negative and they disagree, there is no way inverter
will know.
What if I *want* to run my small DC-DC tapping to a half of the pack
for whatever reason? How does inverter know it's not a leakage??
Victor
--- End Message ---
--- Begin Message ---
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 ---
Bruce,
I think you already know this answer -
When you need a genset to get back home
then do not drive an EV.
It does not make environmental sense (a genset
pollutes at least ten times as bad as a regular
car, so even if you need if for every tenth trip
you better use a regular car iso the genset)
and there is no point in expressing to everyone that
your EV range is not sufficient and you need that
noisy, smelly, polluting genset to keep your "clean"
EV going. It is the wrong message.
You can invest some time in checking beforehand
where you are going, to see if there are other
solutions (plug in at a nearby convenience store
or other friendly neighbor)
or find other solutions (increase your range?)
If all else fails, you may need to leave the EV
and use a gas car for commuting, or drive to a
train station or other public transport.
Someone on this list asked me about a solar panel to
trickle-charge the pack, but that will buy you only
about 1 mile for every hour that the car receives
full sunshine.
So, unless you can build a kind of carport with
solar and charge with higher power, there is no
way to generate enough power to significantly
add to your range.
You already found out that cheap products are often
overrated in their claimed specifications, especially
in continuous duty.
One possible solution is to try and move closer to
the place where you need to go on a daily basis.
I always try to live in the city where my work is,
or in a village nearby.
Success in finding a good solution.
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 bruce parmenter
Sent: Wednesday, April 05, 2006 8:43 PM
To: evlist
Subject: 3kw genset for $315
An ad on one of the discount-store fliers mixed in with the weekly
junk-mail has a 100 lb generator rated at 3000 watts for $315
including tax.
I will have to go to the store and see what I would be buying but
the small picture shows only a dual 110VAC 20 amp out and a
12 VDC terminals. The genset looks like:
http://www.centralonlinesales.com/show_Product.asp?ID=1616
I could mount it on the tire rack that I have on the rear of my
S-10 Blazer. I may also want to mount a jerry can for extra fuel.
-First I am wondering if this generator is one of the types
that was POSTed as a PFC killer?
Since at some point (a year of more) I may have to move to
where the rent is affordable, and where there is no public EV
charging, I may need to use the generator mounted on the back of
my EV to get back home.
The odd part is the rating. If the 12 VDC output is 10 amps, that
is .12 Kw. And the 110 VAC duplex outlet is likely connected to
the same 20 amp breaker which is 2.2 Kw. That is a total of
2.32Kw. What about the other .68Kw?
Running my PFC-30 off a 20 amp 110 VAC outlet will not use all its
capabilities, but the lower charge current is offset by the lighter
genset weight. Mounting it on the tire rack means I do not have to
have a trailer. That reduces both weight and drag.
Any views on this topic are welcome.
Bruce {EVangel} Parmenter
' ____
~/__|o\__
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. http://geocities.com/brucedp/
. EV List Editor, RE & AFV newswires
. (originator of the above ASCII art)
===== Undo Petroleum Everywhere
__________________________________________________
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Tired of spam? Yahoo! Mail has the best spam protection around
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--- End Message ---
--- Begin Message ---
My daily commute is very short but I do 75 miles one way on the weekend,
so the small pack is not really an option. I talked with the guy in
Florida and he said that at 3000 lbs the handling was "fair". He didn't
recommend going any higher. He was using 22 50lb batteries, adding one
more battery had a noticeable effect on handling.
I agree that 1000 lbs in a 944 should be great.
Dave Cover wrote:
Behalf Of Robert Baertsch
Any Porsche experts out there? I hate to sell this car.
-Robert
Robert
I'm doing a 944, similar but different. My reasons should apply to your 911.
The car is well made, it will handle the additional load of a reasonable pack.
I'm planning on
around 1000 lbs of cells.
Very good brakes!
Very aerodynamic.
Reasonable weight, I hope to be under 3000 lbs when complete. Not the lightest,
but...
Fully galvanized body. Will not rust out from under me, even in New England.
(At least not in the
next decade.)
It's a car that will attract attention, and I plan on being an EV evangelist.
I can replace almost any part I need from eBay for a good price.
It's a car I will like driving. Although, getting in and out of a low car is
getting tough on my
old joints.
If the body is in good shape, I'd go for it. But I would cut back on the pack.
Do you know the GVW
of the car? See how it works with a smaller pack before you load it down. What
are you looking
for, range? performance? Do you plan on using it for a daily commuter?
I have a 34 mile round trip I'm shooting for, should be within my reach. I'm
keeping the clutch
and transaxle. There's a guy down in Florida whose done at least one 911, you
should be able to
find him on the net.
Good luck
Dave Cover (in CT)
--- End Message ---
--- Begin Message ---
Mike,
Agreed, trucks are inefficient. They are designed that way.
They also have a purpose, though most of us do not use them
that way.
(hint: it is not to haul your laptop to office on the freeway)
Anyway, this afternoon traffic was light enough to conduct the
return-test and a speed of around 51 MPH used an average 45 Amp
(this time a light breeze from ahead).
That works out to be about 14 kW of power and 275 Wh/mi energy.
The average of 260 Wh/mi at 50 MPH is amazingly efficient and
much better than I expected or have seen before. The only change
I can point to is the lower speed and higher tire pressure, as
I am also running 50 PSI (although my tires are rated 35 PSI).
One stretch was faster, around 57 MPH and took around 60 Amp.
That is exactly in line with earlier values.
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: Wednesday, April 05, 2006 5:11 PM
To: Cor van de Water
Subject: Re: How many amps driving my EV?
My comment about the Saturn is that our trucks are very inefficient
compared other AC systems on the road. I get poked in the ribs about
this every day.
Coming home the other direction at any speed/traffic is still
relevent. Average both directions and see what you get.
Mike
--- In [EMAIL PROTECTED], Cor van de Water <[EMAIL PROTECTED]> wrote:
>
> Hi Mike,
>
> I did not know Saturn makes trucks. Which model?
>
> This was not round-trip (that's why I made the comment about wind)
> my evening commute is usually in rush-hour, so no way to get
> a stable reading like rolling to work halfway the morning
> (after the early morning teleconference)
>
> I won't try to do 52 MPH in the carpool lane, unless the driver(s)
> in front of me do the same.
>
> 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: Wednesday, April 05, 2006 1:43 PM
> To: Cor van de Water
> Subject: Re: How many amps driving my EV?
>
>
> What was the average for both directions? Eddies Saturn gets 157
> WH/mile best case. So we have a ways to go.
>
> Mike
>
>
>
> --- In [EMAIL PROTECTED], Cor van de Water <ev@> wrote:
> >
> > Another datapoint,
> > it looks like the road-users are helping me to get measurements.
> > Today traffic was slow, but rather constant, so I could follow
> > traffic and do 52 MPH most of the route on 101.
> >
> > I admit that there was a light breeze "in the back" and as
> > usual, no height differences.
> >
> > I was amazed when inspecting the V/A logs of my controller
> > where I found almost all current around 40 Amp at 320V,
> > which means I used only 12.8kW to drive down the
> > freeway at 52 MPH in this truck!
> > That is under 250Wh/mi and in line with the efficiency
> > that Mike reported. Wow.
> >
> > Cor van de Water
> > Systems Architect
> > Email: CWater@ Private: http://www.cvandewater.com
> > Skype: cor_van_de_water IM: cor_van_de_water@
> > 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: Cor van de Water
> > Sent: Tuesday, April 04, 2006 3:46 PM
> > To: 'ev@'
> > Subject: RE: How many amps driving my EV?
> >
> >
> > Mike,
> >
> > I know - I should get an Emeter. Too many thing to do right
> > now, so I go by with the data reported from my controller
> > once per second and averaging it over a long trip
> > (more than 5 miles of freeway 101, all just above Bay level,
> > so I am sure there are no height differences!)
> >
> > Only factor I did not compensate for was wind, but I checked
> > that there was no significant storm (trees did not move).
> >
> > 260 Wh/mi is amazingly efficient.
> > It will be difficult to do long distance 45 MPH for me, this
> > speed is not in my commute.
> >
> > Cor van de Water
> > Systems Architect
> > Email: CWater@ Private: http://www.cvandewater.com
> > Skype: cor_van_de_water IM: cor_van_de_water@
> > 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: owner-ev@ [mailto:[EMAIL PROTECTED]
> > Behalf Of Mike Phillips
> > Sent: Tuesday, April 04, 2006 7:38 AM
> > To: ev@
> > Subject: Re: How many amps driving my EV?
> >
> >
> > Hi Cor,
> >
> > Some tips. An Emeter would greatly assist in understanding the real
> > numbers your truck generates. The other thing that was learned is that
> > a no load measurement of the pack can mislead you greatly. A couple of
> > us now use 60 amps as the load used for comparing data between our
> > vehicles. I know the voltage discharge curve is linear, but believing
> > that will bite you.
> >
> > Any incline or decline in the road surface makes a big difference in
> > measuring WH/mile. What I do is go to a known destination, then
> > backagain. That averages out the topology. The Emeter never lies.
Yours
> > eyes and assumptions will lie to you. I found this out when I got my
> > Emeter working. It has educated me greatly. So has recording the data
> > the truck generates on a laptop.
> >
> > My most efficient drive: On the slow drive from Mckee and Capitol, up
> > 101 to 880 west. Then up Coleman to Costco. Costco's Avcon charger is
> > not charging, although it is powered up. The round trip in afternoon
> > rush hour gave me an average of 260 wh/mile. My truck has low rolling
> > resistance tires rated 44 psi now at 50 psi. I can feel the difference
> > over the old tires. Normal lead foot driving gives me 400-450 WH/mile
> > in stop and go traffic.
> >
> > Before I changed the Emeter over to WH/mile it would read AH/mile. The
> > average was 1 AH per mile. .9 AH on the expressways at 45 mph.
> >
> > Mike
> >
> >
> >
> >
> >
> >
> >
> >
> > --- Cor van de Water <CWater@> wrote:
> >
> > > (In the spirit of sharing actual driving consumption to
> > > help battery sizing - I get many questions like that)
> > > My vehicle:
> > > I have a 1994 Chevy S-10 (light truck)
> > > US Electricar conversion, see also:
> > > http://autos.groups.yahoo.com/group/uselectricar/
> > > and I measured the amps while doing
> > > constant speed on the Freeway.
> > > (higher tire pressure and a break-in
> > > period have reduced amps from previous runs)
> > > NOTE: it was drizzling during this trip,
> > > which may result in slightly lower tire friction.
> > >
> > > Driving down Freeway 101 at 56 MPH:
> > > 55 - 60Amp at 312V
> > > (306 - 334 WattHour/mile)
> > >
> > > Going to max throttle, reaching 68 MPH:
> > > 100 - 110Amp. (almost twice the power!)
> > > (450 - 500 Wh/mile)
> > >
> > > I'll stay with 55-60 MPH whenever I can.
> > >
> > > (Taking off uses 140 - 200Amp and reaching
> > > 55 - 60 MPH in this 5000 lbs truck takes
> > > about 30 - 40 seconds. Not fast but adequate
> > > and I can keep up with most traffic but the
> > > gas guzzlers. Suits me perfectly.)
> > >
> > > BTW - Last Saturday I beat my previous max distance
> > > on one charge by going 55 miles and still having 315V
> > > resting voltage (12.1V per battery)
> > > I did notice my acceleration was more limited in the end,
> > > the controller has a configurable low voltage limit, which
> > > is set to 273V (10.5V per battery) and it will cut output
> > > when this limit is reached, so I will be unable to kill
> > > my batteries as long as they stay balanced.
> > > I was able to maintain speed, but hard acceleration quickly
> > > resulted in jerking, a sign of reaching the limit, so it
> > > took longer to get up to speed.
> > > My estimation is that I was down to 30-35% SOC, based on
> > > the numbers for the resting voltage and the approximately
> > > 1 Ah per mile (312V pack) of this truck.
> > >
> > > Note: this pack has 110Ah batteries, 1 hour rating is 80Ah
> > > so 65-70% of that is 52-56 Ah.
> > >
> > > Note2: I still have the idea that my battery wiring has more
> > > series resistance than the internal resistance of the
> > > batteries, which means that the 273V limit is NOT 10.5V at
> > > the battery, dependent on the current.
> > > I need to measure the difference as I suspect the wiring,
> > > connectors and contactor to add too many milliOhms, so the
> > > batteries actually need to supply more current than when
> > > the resistance is lower (more volts => more power =>
> > > shorter acceleration OR I can trade the higher volts for
> > > lower amps to get the same accel). I may also gain range by
> > > reducing this 'waste' and avoid problems with overheating
> > > cabling. (most is only 2 AWG)
> > > (My voltage/current measurement make me believe that the
> > > internal resistance as seen by the controller is almost
> > > 300 milliOhm while the batteries are specified at 4 mOhm,
> > > so the 26 in series should only contribute 104 milliOhm.
> > > Unless the time it takes to go from acceleration to braking
> > > and back to acceleration also allows the batteries to have
> > > internal changes in electrolyte (stratification problem in
> > > AGMs? Lee?)
> > > But since I see a discrepancy of some 196 milliOhms, I want
> > > to check the connections at the controller; the contactor;
> > > the wiring to the battery box and my own wiring inside the
> > > battery box, although I believe that should contribute less
> > > than 50 milliOhm according my own measurements while doing
> > > the installation of the batteries.
> > >
> > > One check point can be to bring one battery's actual
> > > voltage out and measure it with a DVM while doing a launch
> > > and see how far it drops.
> > > Then do a measurement of the voltage across the entire
> > > battery pack, then the voltage across the contactor and
> > > cabling....
> > >
> > > Regards,
> > >
> > > Cor van de Water
> > > Systems Architect
> > > Email: CWater@ Private: http://www.cvandewater.com
> > > Skype: cor_van_de_water IM: cor_van_de_water@
> > > 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
> > >
> > >
> >
> >
> > 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 ---
Sounds like a good case for a 2nd car for weekends. Another thought
is a battery trailer just for the weekend trips. Finally, maybe a
pusher trailer:
<http://www.jstraubel.com/EVpusher/EVpusher2.htm>
<http://www.austinev.org/evalbum/304.html>
I'd vote for keeping the Porsche light and fun if you can.
--- Robert Baertsch <[EMAIL PROTECTED]> wrote:
> My daily commute is very short but I do 75 miles one way on the
> weekend,
> so the small pack is not really an option. I talked with the guy
> in
> Florida and he said that at 3000 lbs the handling was "fair". He
> didn't
> recommend going any higher. He was using 22 50lb batteries, adding
> one
> more battery had a noticeable effect on handling.
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--- Begin Message ---
Hello Jeff,
Check you battery pack volt at NO Load vs at 75 amp Load.
At 100% charge the voltage should be 12.74 volts per 12 volts at 1.277 SG.
at NO Load and 11.9 volts per 12 volts at 75 amp Load.
If its in this range then the battery pack is ok. If not, then first check
if any of the battery connectors perform a shrink back that causes increase
in resistance. This should be done anyway if you never done that.
It is common on a new set of batteries to lose the battery connection torque
by up to 5 inch lbs in the first run of 5 miles. I will normally re-torque
the battery connections on a new pack every 5 miles until they settle down.
It is best to drive at a lower speed for short distances to break in a
battery pack and motor. I will normally do this for the first 1000 miles
while checking, double checking, triple checking and until I feel it is
ready to increase the speed and distance.
About once a month, I do a shunt test on the battery links, by connecting up
a ma meter in parallel with the battery link and reading the ampere while
the charging is running. All battery links ampere reading should be the
same. Tightening the battery connection, you will decrease the resistance
and the ampere reading in you shunt test.
Testing the battery connectors this way is a easy way to find a high
resistance connector.
One time with my 300 AH pack, I was accelerating from 0 to 60 mph drawing
about 600 amps and all of a sudden I lost my power. The voltage drop was
11.10 volts per 12 volt battery or 166.5 volts at a 75 amp load on a 180
volt pack. The controller was program to cut out at 160 volts.
I found that one of the battery connectors lost all its torque where I could
rotate the connector by hand.
Roland
----- Original Message -----
From: "Jeff Shanab" <[EMAIL PROTECTED]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Wednesday, April 05, 2006 8:54 PM
Subject: EV Performance
> In all the discussion about performance recently I was curious, I had
> been gentle since my EVent (blown up motor for those that don't know)
> So on my way home, I was coming out of the target parking lot and needed
> to get accross 3 lanes, I was already rolling in second and floored it.
> OK, so I can spin the tires with 750 lbs over the rear axle! The pack
> was about 40% down and I was immediatly seeing red lights in my mirror.
> Thank god it was just the low voltage LED's on the rear battery pack (is
> that normal for excide orbitals and rudman regs?).
>
>
> The car is not as peppy as it was and I think the throttle may not be
> makeing 100%, I need to check the pot
> I also thing the tires are to old and dry to judge breaking traction on,
> but I wnated to run this question past the speed freaks.
>
> If there is something wrong that is causeing the car to accelerate
> slower than before, what do these symptoms indicate.
>
> In the first 1/2 of the throttle it feels like the pack is almost dead,
> when it is fresh.; ie it doesn;t seem to draw the amps requested.
> In the second half of the throttle, as the rpm's pick up it seems to
> climb in torque or rate of rpm climb, not go to sleep, I shift long
> before I feel the "go to sleep point"
> In this test it came up quick, but I got out of the throttle until it
> hooked up then continued, it seemed as if the acceleration curve had a
> flat which I interpret as the throttle not going to 100%.
> Starting in 3rd was ok, now it is blah, I now shift down to 2nd at every
> light and upshift to 3rd, before I could drive around in 3rd.
> Commutator is not sooty black but very dark
> http://www.morgancarbon.com/technicalsupport/patina.htm
> darker than picture 2 with a tiny amount of blotchy like third
> picture in the middle of each comm bar, but more uniform.
>
>
> Things to check
> Zilla settings,motor timing, sources of higher than normal resistance
>
> Oh, the setup, 24 orbitals connected with 2/0 super-flex and 2/0 from
> zilla 1k to motor
>
>
--- End Message ---
--- Begin Message ---
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!
It's also worth noting that this has little to do with EVs, it's just
taking a standard gas car engine and using it to drive around twice the
weight it was designed for and with the drag of nearly two vehicles. So
it is a step back for the fuel and environmental issues while it's being
used. You'd have to make the case that using it (or even having it
hooked up) a small percentage of the time allows the EV to be used much
more often than it would otherwise be used.
Danny
David Dymaxion wrote:
Sounds like a good case for a 2nd car for weekends. Another thought
is a battery trailer just for the weekend trips. Finally, maybe a
pusher trailer:
<http://www.jstraubel.com/EVpusher/EVpusher2.htm>
<http://www.austinev.org/evalbum/304.html>
I'd vote for keeping the Porsche light and fun if you can.
--- End Message ---
--- Begin Message ---
Yeah, did you catch the calcs I took a shot at a week or two ago? With
the most efficient genny out there your mpg is pretty scary, potentially
like 10 mpg. Another reported the HC emissions off those relatively
clean Honda OHV 4-strokes are still like 10x-30x worse than allowed for
a car. It would only make sense on paper if like 95%-99% of your miles
were using power sourced from the grid. Otherwise, you're being
completely counterproductive. The situation probably gets far worse
with these big, cheap gens.
Danny
Cor van de Water wrote:
Bruce,
I think you already know this answer -
When you need a genset to get back home
then do not drive an EV.
It does not make environmental sense (a genset
pollutes at least ten times as bad as a regular
car, so even if you need if for every tenth trip
you better use a regular car iso the genset)
and there is no point in expressing to everyone that
your EV range is not sufficient and you need that
noisy, smelly, polluting genset to keep your "clean"
EV going. It is the wrong message.
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
>> a common fault would be a short to ground somewhere in the battery
>> pack. So, you create such a fault (with a resistor, so you don't
>> literally have a short and so won't harm anything). If the Siemens
>> inverter includes ground fault protection, then it should detect
>> the resistive short to ground.
Victor Tikhonov wrote:
> How? Unless yo have sensitive current sensors in the pack positive
> and pack negative and they disagree, there is no way inverter will
> know.
I've seen two methods in use.
One is to use a DC current sensor, like the LEM modules. Both wires from
the traction pack run through the same sensor, oriented so their
currents cancel. If there is no leakage current to ground, then these
two currents are equal and opposite, so they cancel. If there *is* a
ground fault current, the LEM sensor detect it and shuts things down.
The other is to use two relays and a resistor. Step one is to connect
the resistor from Pack+ to ground, and measure the voltage across it.
Step two is to do the same thing from Pack- to ground. In both cases,
the voltage should be zero. The only time you'd have voltage across this
resistor is if there is a SECOND path to ground caused by a fault
somewhere.
> What if I *want* to run my small DC-DC tapping to a half of the pack
> for whatever reason? How does inverter know it's not a leakage?
It works fine, as long as nothing is grounded.
--
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 ---
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 ---
--- Begin Message ---
Bruce {EVangel} Parmenter wrote:
An ad on one of the discount-store fliers mixed in with the weekly
junk-mail has a 100 lb generator rated at 3000 watts for $315
including tax.
I will have to go to the store and see what I would be buying but
the small picture shows only a dual 110VAC 20 amp out and a
12 VDC terminals. The genset looks like:
http://www.centralonlinesales.com/show_Product.asp?ID=1616
This looks like the same one I was looking at last night at Big
Lots. Their price was $288 plus tax. It was rated 25 Amps at 120
Volts. Obvious Honda knock-off, but nothing like Honda quality. It
looked to me like getting it last might be a problem, just not all
that well built. I am tempted to get one anyway just to play with
and to keep the lights on when the power fails again.
BTW, does anyone know what the hazards of running a Lester or Bycan
charger in 120 volt mode from one of these might be? I know I will
get asked about this by one of our chapter members at our next
gathering when he sees this thread.
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 ---
--- Begin Message ---
Hi all,
Because my old harddrive crashed last night, I had to
buy me a new one, but I also lost a lot of emails of
this list which where interesting to me, so I have to
look thru the digests to find them back.
One question which still puzzles me what the best
battery would be, as I can see it is:
low voltage-high ah battery = long range
high voltage-low ah battery = fast acceleration
Is this correct or is my harddrive(brain) also failing
thx for the info
Pascal
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--- Begin Message ---
How do I un-enroll from this list?
Bob Phelps
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--- Begin Message ---
At 05:15 AM 6/04/06 -0700, Pascal wrote:
Hi all,
<snip> One question which still puzzles me what the best
battery would be, as I can see it is:
low voltage-high ah battery = long range
high voltage-low ah battery = fast acceleration
Is this correct or is my harddrive(brain) also failing
Hi Pascal - and All
Fairer to state is that with *normally available parts* low voltage DC will
give you lower acceleration, longer range, when comparing to higher voltage
DC will give you less range, higher acceleration rates. Although if you
have a high voltage DC system and drive conservatively, it may give you
slightly greater range than a low voltage system.
Let me illustrate that: Car of (x) weight with two strings of a given
battery in paralell to give a low voltage system and a controller and motor
that matches the max battery voltage. Use a high-voltage version of the
same controller, use the same motor and the batteries in a single string,
and the current from the batteries to the controller will be halved at
otherwise identical power levels - so the resistive losses halved and power
losses quatered. But all other efficiencies will be pretty much unchanged,
but the system can deliver more power into the motor at higher RPM due to
the greater "slope" between battery voltage and motor voltage - and drivers
being human, make that happen, reducing range by 'burning' more power.
AC is normally higher voltage but moderate power levels with nice
sophistication of features and tight integration of motor and controller,
defying the ability to give a high/low voltage answer.
High Ah battery is longer range than lower Ah battery, but again the
comparison can be apples and oranges, since a high Ah LiPo battey may give
you greater acceleration than wet lead/Acid.
Hope this helps
James
--- End Message ---
