amusing problem

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amusing problem

Willie McKemie
My air conditioner saga begins with having the compressor belt
contacting too small a sector on the pulley; it slipped a lot and ate
belts.  Having the alternator removed and wrapping the belt more than
180 degrees around the compressor pulley solved that problem.  With hot
weather upon us and some of my other EV problems resolved, I've been
attempting to use the air conditioner.  While the AC clutch is engaged,
there are noticeable vibrations at around 2000 rpm (one of the resolved
problems is getting the tachometer to work!) and a bit above 3000 rpm.  
After tightening the belt a bit and going on a trip that required
working around the vibration speeds, I was was pondering the problem.  
"I bet the idler is on the tension side of the compressor belt!" was
epithany I had.  Lifted the hood, spun the motor, and, sure enough, the
idler is on the wrong side of the compressor.  Be warned.  This is not
a problem that I would have foreseen and I imagine many others could
overlook it as well.

"If it CAN jump up and bite you, it WILL jump up and bite you."


--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  156 days  7 hours 55 minutes

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who needs AC was Re: amusing problem

harry henderson
i did not notice until it was pointed out to me [i'm a bit dense], by a group to whom i was demoing my bus, that my vw WAS cooler than expected.  during summer when i'm not on the bike i would run my AC in my ICE but with the 'voltswagon' i did not have that option and i've been unaware of the difference.  i guess with all the windows open all the time [i'm not worried about theft] and the white top [minus the solar panel] plus the isolated roof [camper van] and no heat from the motor it does stay cool even in albuquerque.  another EV plus  


harry

Albuquerque, NM
current bike:  http://www.austinev.org/evalbum/1179
current non-bike: http://evalbum.com/1000


--- On Sat, 8/14/10, Willie McKemie <[hidden email]> wrote:

> From: Willie McKemie <[hidden email]>
> Subject: [EVDL] amusing problem
> To: "Electric Vehicle Discussion List" <[hidden email]>
> Date: Saturday, August 14, 2010, 1:12 PM
> My air conditioner saga begins with
> having the compressor belt
> contacting too small a sector on the pulley; it slipped a
> lot and ate
> belts.  Having the alternator removed and wrapping the
> belt more than
> 180 degrees around the compressor pulley solved that
> problem.  With hot
> weather upon us and some of my other EV problems resolved,
> I've been
> attempting to use the air conditioner.  While the AC
> clutch is engaged,
> there are noticeable vibrations at around 2000 rpm (one of
> the resolved
> problems is getting the tachometer to work!) and a bit
> above 3000 rpm. 
> After tightening the belt a bit and going on a trip that
> required
> working around the vibration speeds, I was was pondering
> the problem. 
> "I bet the idler is on the tension side of the compressor
> belt!" was
> epithany I had.  Lifted the hood, spun the motor, and,
> sure enough, the
> idler is on the wrong side of the compressor.  Be
> warned.  This is not
> a problem that I would have foreseen and I imagine many
> others could
> overlook it as well.
>
> "If it CAN jump up and bite you, it WILL jump up and bite
> you."
>
>
> --
> Willie, ONWARD!  Through the fog!
> http://counter.li.org Linux registered user #228836
> since 1995
> Debian3.1/GNU/Linux system uptime  156 days  7
> hours 55 minutes
>
> _______________________________________________
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>


     

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Re: amusing problem

Jeffrey Jenkins
In reply to this post by Willie McKemie
Willie McKemie-3 wrote
...(one of the resolved problems is getting the tachometer to work!)...
Was that the car's tachometer, or was it for the Soliton1?

-Jeffrey Jenkins
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Re: amusing problem

Willie McKemie
On Sun, Aug 15, 2010 at 11:05:08AM -0700, Jeffrey Jenkins wrote:
>
>
> Willie McKemie-3 wrote:
> >
> > ...(one of the resolved problems is getting the tachometer to work!)...
>
> Was that the car's tachometer, or was it for the Soliton1?

Dash tachometer.

While I have your attention, I now have the Soliton1 light on my dash
too.  It has been going into slow blink after traveling some in our hot
weather.  100 + deg highs now.  Goes into slow blink even with very
conservative driving.  I presume that is likely to mean the controller
is getting hot.  I'm air cooled.  Since I haven't previously been able
to see the controller light, I don't know whether this is a new or hot
weather phenomena.

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  158 days 16 hours 39 minutes

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Re: amusing problem

martin-7
On 2010-08-17 05:43, Willie McKemie wrote:

> On Sun, Aug 15, 2010 at 11:05:08AM -0700, Jeffrey Jenkins wrote:
>    
>>
>> Willie McKemie-3 wrote:
>>      
>>> ...(one of the resolved problems is getting the tachometer to work!)...
>>>        
>> Was that the car's tachometer, or was it for the Soliton1?
>>      
> Dash tachometer.
>
> While I have your attention, I now have the Soliton1 light on my dash
> too.  It has been going into slow blink after traveling some in our hot
> weather.  100 + deg highs now.  Goes into slow blink even with very
> conservative driving.  I presume that is likely to mean the controller
> is getting hot.  I'm air cooled.  Since I haven't previously been able
> to see the controller light, I don't know whether this is a new or hot
> weather phenomena.
>    

There are four cases the lamp can start blinking slowly:

  - Motor overtemp (if you've connected the motors temp switch to one of
the inputs)
  - Controller overtemp (over 65C/149F)
  - Temp sensor broken (not likely since it doesn't blink from start,
right?)
  - Over-RPM (I think we can ignore that too, right? ;) )

So yep, seems your Sol is running a bit hot. Except from that the
current limit will slowly dial down max current with rising temperature,
it's not a big deal. Between 55C/131F to 95C/203F max current will be
linearly decreased so that at 95C the controller won't deliver any
current at all, so I'd guess that somewhere above 80C you'll start to
get a problem maintaining cruising speed.

If it's regularly that hot out, perhaps you should consider to move the
controller to where it gets better air flow or adding water cooling?

/M

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Re: amusing problem

Willie McKemie
On Tue, Aug 17, 2010 at 08:59:30AM +0200, Martin wrote:
>
> There are four cases the lamp can start blinking slowly:
>
>   - Motor overtemp (if you've connected the motors temp switch to one of
> the inputs)
>   - Controller overtemp (over 65C/149F)
>   - Temp sensor broken (not likely since it doesn't blink from start,
> right?)
>   - Over-RPM (I think we can ignore that too, right? ;) )

Yes.

Without doing anything silly like referring to the documentation, I'll
ask: Does the configuration display give me any dynamic information?  
That is, can I consult my netbook while driving (and ignoring traffic)
and find the cause of the slow blink?  I guess I could disconnect the
motor temp sensor to see it that is the problem.  I'm guessing it is
almost certainly controller temperature though.  I'll probably just
wait until ambient temperatures moderate and see if the blink goes
away.  From a cool start, it takes 10-15 miles for the slow blink to
begin.  It does immediately resume after a short stop of 5-10 minutes.
If the controller protects itself (as it seems) it is no big deal.
This happens with conservative driving: accelerating at 200-300 amps
and cruising at 80-120 amps.

We're in the middle of our hell season.  Weeks on end of 100+ degree
afternoons, night time dropping only to 80 degrees or thereabouts.

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  159 days 24 min minutes

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Re: amusing problem

martin-7
On 2010-08-17 13:38, Willie McKemie wrote:

> On Tue, Aug 17, 2010 at 08:59:30AM +0200, Martin wrote:
>    
>> There are four cases the lamp can start blinking slowly:
>>
>>    - Motor overtemp (if you've connected the motors temp switch to one of
>> the inputs)
>>    - Controller overtemp (over 65C/149F)
>>    - Temp sensor broken (not likely since it doesn't blink from start,
>> right?)
>>    - Over-RPM (I think we can ignore that too, right? ;) )
>>      
> Yes.
>
> Without doing anything silly like referring to the documentation, I'll
> ask: Does the configuration display give me any dynamic information?
>    

Um. Nope. But you can run the logger in a DOS-shell (or, if you run
UNIX, a terminal) and get some of the log data in plain text as you
drive. Or you can, of course, add a meter to one of the outputs and ask
the controller to report the temperature to it.

> I guess I could disconnect the
> motor temp sensor to see it that is the problem.

Or just disable it in the web interface.

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Re: amusing problem

Jeffrey Jenkins
In reply to this post by Willie McKemie
Willie McKemie-3 wrote
...From a cool start, it takes 10-15 miles for the slow blink to
begin.  It does immediately resume after a short stop of 5-10 minutes.
If the controller protects itself (as it seems) it is no big deal.
This happens with conservative driving: accelerating at 200-300 amps
and cruising at 80-120 amps.
Yes, this is almost assuredly the controller telling you that its heatsink temp has exceeded 65C. It would be pretty stupid of us to not protect the controller against overheating, btw, so I'll pretend you didn't wonder if it does... ;)

This is covered on p20 of our Fine Manual which I spent 3 thankless weeks of my life writing... not that I'm bitter about that or anything... :D

Practically speaking, once the ambient temp exceeds 30C it is pretty much impossible to keep the Soliton1's heatsink temp below 55C with just the built-in fans for cooling, even with very conservative driving. This is especially true if the air exhausted from the motor can reach the controller. Keep in mind the relative efficiencies of the two: the controller is about 97% on average; the typical DC motor will be about 85% best case. So, if the controller is delivering 20kW of power to the motor, expect it to shed about 600W as heat and the motor to shed at least 3000W! As current through the motor goes up the efficiency goes down (because of i²r) so high currents produce disproportionately higher amounts of waste heat.

We foresaw this which is why we gave the Soliton1 both a heatsink with fans, as well as cross-drilling for liquid cooling. We simply couldn't imagine how a controller with just a finned heatsink could ever provide halfway decent performance in an EV (just liquid cooling is fine, too, though it forces your customers to buy a pump, hoses, reservoir fans and radiator and that really should be included with the controller since it isn't actually "optional" at that point).

-Jeffrey Jenkins
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Re: amusing problem

dave cover-2
Jeff

On the subject of heat, does the Soliton provide a way to drive a temp
gauge in the dash? Or can the temp be derived from data available?

Thanks

Dave Cover

On Tue, Aug 17, 2010 at 7:51 AM, Jeffrey Jenkins
<[hidden email]> wrote:

>
>
> Willie McKemie-3 wrote:
>>
>> ...From a cool start, it takes 10-15 miles for the slow blink to
>> begin.  It does immediately resume after a short stop of 5-10 minutes.
>> If the controller protects itself (as it seems) it is no big deal.
>> This happens with conservative driving: accelerating at 200-300 amps
>> and cruising at 80-120 amps.
>
> Yes, this is almost assuredly the controller telling you that its heatsink
> temp has exceeded 65C. It would be pretty stupid of us to not protect the
> controller against overheating, btw, so I'll pretend you didn't wonder if it
> does... ;)
>
> This is covered on p20 of our Fine Manual which I spent 3 thankless weeks of
> my life writing... not that I'm bitter about that or anything... :D
>
> Practically speaking, once the ambient temp exceeds 30C it is pretty much
> impossible to keep the Soliton1's heatsink temp below 55C with just the
> built-in fans for cooling, even with very conservative driving. This is
> especially true if the air exhausted from the motor can reach the
> controller. Keep in mind the relative efficiencies of the two: the
> controller is about 97% on average; the typical DC motor will be about 85%
> best case. So, if the controller is delivering 20kW of power to the motor,
> expect it to shed about 600W as heat and the motor to shed at least 3000W!
> As current through the motor goes up the efficiency goes down (because of
> i²r) so high currents produce disproportionately higher amounts of waste
> heat.
>
> We foresaw this which is why we gave the Soliton1 both a heatsink with fans,
> as well as cross-drilling for liquid cooling. We simply couldn't imagine how
> a controller with just a finned heatsink could ever provide halfway decent
> performance in an EV (just liquid cooling is fine, too, though it forces
> your customers to buy a pump, hoses, reservoir fans and radiator and that
> really should be included with the controller since it isn't actually
> "optional" at that point).
>
> -Jeffrey Jenkins
>
> --
> View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/amusing-problem-tp2325428p2328190.html
> Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.
>
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--
http://www.evalbum.com/2149

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Re: amusing problem

Jeffrey Jenkins
dave cover-2 wrote
On the subject of heat, does the Soliton provide a way to drive a temp
gauge in the dash? Or can the temp be derived from data available?
Sort of, and yes.

The Soliton1 has three programmable outputs that were originally intended to control relays and contactors and such. However, a customer asked if it would be possible to get them to output an analog signal that could represent battery current. We found that it was possible by PWMing them from 0-100% duty cycle. This signal can drive an analog gauge directly - the inertia of the mechanical movement integrates the signal perfectly - or it can be integrated with an RC network and drive a digital panel meter.

However, this is definitely a "hacker's special" sort of thing, and we absolutely can't predict whether one will be able to directly drive existing dashboard gauges in their particular vehicle (particular the newest ones where a microcontroller is invariably used to drive the gauges, analog or not).

The Soliton1 also constantly streams performance data (in UDP format - source code available) to the ethernet port in 10ms intervals (10x more frequently than a Zilla), one piece of which is the heatsink temp.

Hope that helps...

-Jeff
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Re: amusing problem

Willie McKemie
In reply to this post by Jeffrey Jenkins
On Tue, Aug 17, 2010 at 04:51:18AM -0700, Jeffrey Jenkins wrote:
>
> This is covered on p20 of our Fine Manual which I spent 3 thankless weeks of
> my life writing... not that I'm bitter about that or anything... :D

NOT "thankless":  Thank you for writing such a fine manual!  You're
suggesting I should read it more thoroughly?  :-)

I took the car on an about 100 mile run in the "cool" of the morning
yesterday.  80-90 degrees.  No blinking from the controller.  But, not
using the air conditioner either.  So, I'm guessing it is only a
problem in 100 degree weather.  My controller is no longer mounted to
the motor, but it is directly above.  Perhaps I can install a baffle.  
Relocating the controller is not an option though installing liquid
cooling is.

Incidentally, the battery is about 180 ah down, I have not recharged
from that trip; I will continue to draw the battery down to get an
estimate of it's capacity.  About a year ago, I drew about 300 ah out
of the 260 ah cells.  Last year, I measured all cell voltages
manually and frequently as I approached the end.  This time, I have
confidence in my low cell voltage alarm so I see no need to manually
monitor cells.  I now have just over 10K miles on the pack.

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  160 days  1 hours 48 minutes

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Battery capacity

Willie McKemie
On Wed, Aug 18, 2010 at 08:04:12AM -0500, Willie McKemie wrote:

> Incidentally, the battery is about 180 ah down, I have not recharged
> from that trip; I will continue to draw the battery down to get an
> estimate of it's capacity.  About a year ago, I drew about 300 ah out
> of the 260 ah cells.  Last year, I measured all cell voltages
> manually and frequently as I approached the end.  This time, I have
> confidence in my low cell voltage alarm so I see no need to manually
> monitor cells.  I now have just over 10K miles on the pack.

I posted this to the ThunderSky list:

---
About a year ago, as a capacity test, I drew my pack of 45 TS-LP260
down so the lowest cell was about 3 volts.  I got 300 ah out of it.
I just finished another similar test.  Took the pack down to 135v
which is an average of 3v; some cells were down to about 2.8.  I got
280 ah out of it.  The pack has a bit more than 10,000 miles on it.

I've been claiming 120 mile range; I typically use a bit less than 2ah
per mile, more with air conditioning.  At about 30 mph, I can get it
down as low as about 1.5 ah/mile.  I put 140 miles on it during the
recent test.

Amp-hours measured with a TBS meter.

These are pretty fuzzy numbers, but I may be losing 20ah per year.  If
so, my pack may last 5-8 more years; it is about 2 years old now.
---

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  161 days  7 hours 47 minutes

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Re: Battery capacity

Myles Twete
That would be a bummer if these Lithium cells only last as long as a well
treated and not overused flooded pack.
I'm still using T105's that I purchased in 1999....also using a bunch of
used T105's that I got for $20 each.  As none of my electrics are daily
drivers, I'd only be willing to go lithium if there were guarantees on
actual life---not just cycle life.  Your reported experience casts some
doubt as to actual life.

-Myles Twete, Portland, Or.

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf
Of Willie McKemie
Sent: Thursday, August 19, 2010 11:52 AM
To: Electric Vehicle Discussion List
Subject: [EVDL] Battery capacity

On Wed, Aug 18, 2010 at 08:04:12AM -0500, Willie McKemie wrote:

> Incidentally, the battery is about 180 ah down, I have not recharged
> from that trip; I will continue to draw the battery down to get an
> estimate of it's capacity.  About a year ago, I drew about 300 ah out
> of the 260 ah cells.  Last year, I measured all cell voltages
> manually and frequently as I approached the end.  This time, I have
> confidence in my low cell voltage alarm so I see no need to manually
> monitor cells.  I now have just over 10K miles on the pack.

I posted this to the ThunderSky list:

---
About a year ago, as a capacity test, I drew my pack of 45 TS-LP260
down so the lowest cell was about 3 volts.  I got 300 ah out of it.
I just finished another similar test.  Took the pack down to 135v
which is an average of 3v; some cells were down to about 2.8.  I got
280 ah out of it.  The pack has a bit more than 10,000 miles on it.

I've been claiming 120 mile range; I typically use a bit less than 2ah
per mile, more with air conditioning.  At about 30 mph, I can get it
down as low as about 1.5 ah/mile.  I put 140 miles on it during the
recent test.

Amp-hours measured with a TBS meter.

These are pretty fuzzy numbers, but I may be losing 20ah per year.  If
so, my pack may last 5-8 more years; it is about 2 years old now.
---

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  161 days  7 hours 47 minutes

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Re: Battery capacity

Willie McKemie
On Thu, Aug 19, 2010 at 10:58:38AM -0700, Myles Twete wrote:
> That would be a bummer if these Lithium cells only last as long as a well
> treated and not overused flooded pack.
> I'm still using T105's that I purchased in 1999....also using a bunch of
> used T105's that I got for $20 each.  As none of my electrics are daily
> drivers, I'd only be willing to go lithium if there were guarantees on
> actual life---not just cycle life.  Your reported experience casts some
> doubt as to actual life.

Perhaps you didn't get my drift on "fuzzy" numbers?  Lithiums are
"supposed" to last about ten years.  My numbers are too fuzzy to draw
conclusions of shorter life.  Look here again next year for new data.

My pack seems to have gone from 115% of rated capacity to 108% of
rated capacity in one year.  Both of those numbers have some unknown
error.  I don't find that alarming.  The 10,000+ miles represents
somewhere around 200 cycles.  How many miles and cycles do you have
on your long lived floodies?  I figure the 10,000+ miles represents
at least one flooded life span.  Prospects for my lithiums lasting as
long as five sets of floodies seem good.  If that happens, I will be
money ahead.  Not to mention that there is no way that floodies could
give me the needed range.

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  161 days  8 hours 25 minutes

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Re: Battery capacity

Pinetreeporsche
In reply to this post by Willie McKemie
"My pack seems to have gone from 115% of rated capacity to 108% of 
rated capacity in one year.  Both of those numbers have some unknown 
error.  I don't find that alarming.  The 10,000+ miles represents 
somewhere around 200 cycles.  How many miles and cycles do you have 
on your long lived floodies?  I figure the 10,000+ miles represents 
at least one flooded life span.  Prospects for my lithiums lasting as 
long as five sets of floodies seem good.  If that happens, I will be 
money ahead.  Not to mention that there is no way that floodies could 
give me the needed range."  -Willie M
Just curious, what was the initial cost of the TS batts, and what would they cost new now, if you know.  And:  if you did 10,000 miles in a year, and are hoping for, say, 7 or 8 more, then that might come out to 75,000 replacement-- about 1/2 to 1/3 the life expectancy of a typical ICE car.  What's the cost (of batteries, not electricity) per mile?  Are the old TS batts worth anything on a recycle trade-in?  And, what's your electricity cost per mile?  In other words, give us a hoped-for overall cost per mile, if you can, please.  (I'm considering TS for my little project, and wondered what your economics work out to.) -Chris H


     
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Maybe not as bad as you fear, (was: Battery capacity)

Bill Dube
In reply to this post by Willie McKemie
Typically, the calendar capacity loss is not linear. You lose a lot
the first year, and then less with each successive year.

         The mechanism for the loss is contamination driven. There
are two ways that the active materials can combine with contaminants.
The contaminants were there inside the cell from the beginning. The
contaminants find their way in from the outside world. These
contaminants can be water or oxygen or ???.

         The frist year gets the big dose because the contaminants
both diffuse in from outside, and also evolve from the materials
inside the cells. As time goes by, the internal supply of
contaminants gets depleted. Thus, the aging process slows down with
the dwindling supply of internal contaminants.

         If the case and seals are high quality, and not damaged,
then the aging process slows down a lot over time. The cycle life is
also typically not linear, but is not as severely non-linear as
calendar life loss.

         The loss you measure the first year might extrapolate to a
ten year lifespan, but the reality might be twenty years or more
because of non-linear effects.

Bill D.

At 02:52 PM 8/19/2010, you wrote:

>On Wed, Aug 18, 2010 at 08:04:12AM -0500, Willie McKemie wrote:
>
> > Incidentally, the battery is about 180 ah down, I have not recharged
> > from that trip; I will continue to draw the battery down to get an
> > estimate of it's capacity.  About a year ago, I drew about 300 ah out
> > of the 260 ah cells.  Last year, I measured all cell voltages
> > manually and frequently as I approached the end.  This time, I have
> > confidence in my low cell voltage alarm so I see no need to manually
> > monitor cells.  I now have just over 10K miles on the pack.
>
>I posted this to the ThunderSky list:
>
>---
>About a year ago, as a capacity test, I drew my pack of 45 TS-LP260
>down so the lowest cell was about 3 volts.  I got 300 ah out of it.
>I just finished another similar test.  Took the pack down to 135v
>which is an average of 3v; some cells were down to about 2.8.  I got
>280 ah out of it.  The pack has a bit more than 10,000 miles on it.
>
>I've been claiming 120 mile range; I typically use a bit less than 2ah
>per mile, more with air conditioning.  At about 30 mph, I can get it
>down as low as about 1.5 ah/mile.  I put 140 miles on it during the
>recent test.
>
>Amp-hours measured with a TBS meter.
>
>These are pretty fuzzy numbers, but I may be losing 20ah per year.  If
>so, my pack may last 5-8 more years; it is about 2 years old now.
>---
>
>--
>Willie, ONWARD!  Through the fog!
>http://counter.li.org Linux registered user #228836 since 1995
>Debian3.1/GNU/Linux system uptime  161 days  7 hours 47 minutes
>
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Re: Battery capacity

Willie McKemie
In reply to this post by Pinetreeporsche
On Thu, Aug 19, 2010 at 12:39:16PM -0700, L. Chris Hager wrote:
> Just curious, what was the initial cost of the TS batts, and what would they cost new now, if you know.  And:  if you did 10,000 miles in a year, and are hoping for, say, 7 or 8 more, then that might come out to 75,000 replacement-- about 1/2 to 1/3 the life expectancy of a typical ICE car.  What's the cost (of batteries, not electricity) per mile?  Are the old TS batts worth anything on a recycle trade-in?  And, what's your electricity cost per mile?  In other words, give us a hoped-for overall cost per mile, if you can, please.  (I'm considering TS for my little project, and wondered what your economics work out to.) -Chris H

I paid about $1.60 per ah for my cells.  Now, they are going for more
like $1.30.  That would put my pack cost at almost $19K without
considering other costs like BMS.  If I can put only 10K miles per year
on my EV (non battery problems have limited my vehicle use) and the
battery lasts ten years, my per mile battery cost is $.19.  Using
current cell prices, it would be about $.15.  The cells are supposed
to go 2000-4000 cycles.  2000 100 mile cycles would be 200,000 miles
or $.10/mile with my price or $.08 with current price.  For the VERY
best scenario, 4000 cycles within 10 years would yield $.05 and $.04
per mile costs.

Truly: YMMV

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  161 days 10 hours 00 minutes

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Re: Battery capacity

Willie McKemie
On Thu, Aug 19, 2010 at 04:17:30PM -0500, Willie McKemie wrote:

> On Thu, Aug 19, 2010 at 12:39:16PM -0700, L. Chris Hager wrote:
> > Just curious, what was the initial cost of the TS batts, and what would they cost new now, if you know.  And:  if you did 10,000 miles in a year, and are hoping for, say, 7 or 8 more, then that might come out to 75,000 replacement-- about 1/2 to 1/3 the life expectancy of a typical ICE car.  What's the cost (of batteries, not electricity) per mile?  Are the old TS batts worth anything on a recycle trade-in?  And, what's your electricity cost per mile?  In other words, give us a hoped-for overall cost per mile, if you can, please.  (I'm considering TS for my little project, and wondered what your economics work out to.) -Chris H
>
> I paid about $1.60 per ah for my cells.  Now, they are going for more
> like $1.30.  That would put my pack cost at almost $19K without
> considering other costs like BMS.  If I can put only 10K miles per year
> on my EV (non battery problems have limited my vehicle use) and the
> battery lasts ten years, my per mile battery cost is $.19.  Using
> current cell prices, it would be about $.15.  The cells are supposed
> to go 2000-4000 cycles.  2000 100 mile cycles would be 200,000 miles
> or $.10/mile with my price or $.08 with current price.  For the VERY
> best scenario, 4000 cycles within 10 years would yield $.05 and $.04
> per mile costs.

Our electricity cost is $.10-$.11 per KWH, about $.02 per mile.

I don't expect the salvage value of the battery to be significant.

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  161 days 10 hours 27 minutes

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Re: amusing problem

Cory Cross-2
In reply to this post by Jeffrey Jenkins
Jeffrey Jenkins wrote:
> We simply couldn't imagine how
> a controller with just a finned heatsink could ever provide halfway decent
> performance in an EV
Maybe you should reevaluate your opinion on synchronous rectification
then... :)

Cory

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Re: amusing problem

Jeffrey Jenkins
Cory Cross-2 wrote
Jeffrey Jenkins wrote:
> We simply couldn't imagine how
> a controller with just a finned heatsink could ever provide halfway decent
> performance in an EV
Maybe you should reevaluate your opinion on synchronous rectification
then... :)
Well, you can't do synchronous rectification with IGBTs, but even if that weren't an issue SR doesn't get you much for your troubles at 144V, much less 300V. Why go to all that trouble to only save an extra 0.4-0.8V of forward drop, and only during the freewheeling periods as well?



 
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