This a today's trabscription from Jack Rickard on FB 8hrs ago...
A Dark and Sunny Sunday....:
I was really quite energized this week and had planned quite a show for the
weekend. But we were kind of overwhelmed with orders and order problems towards
the end of the week, and so increasingly I'm finding that the only time I can
put focused effort into a project is at home in the mornings or on the weekends
at the shop when my "help" isn't there to "help". That's tradiionally when I
have edited and uploaded videos.
But I've been obsessing recently on the Tesla Drive Unit. Collin Kidder and I
have been going back and forth in kind of intense fashion between a controller
box and the EVIC display to control the Tesla Model S drive train. And
actually, we are getting very close.
So close that I went to the shop Saturday afternoon with some new code we'd
been working on intending to shoot a video segment showing this remarkable
display we have now that controls the drive unit.
As always, it didn't work "exactly" the way I pictured it from the comfort of
the bedroom. But to give you some idea, we're kind of doing to doing a 500 slot
ring buffer to do a continuous averaging of watt-hours per mile smoothly so we
can predict the range remaining in the pack in miles per hour and kilometers
per hour. This adds a new sample about every 10 seconds and averages it over
the last 500 samples. It won't be any better than the almost comical one in the
ICE Escalade, but it's traditional to have this displayed.
So I kept at it. Deadline 6:00 PM Saturday as I had promised the wife I would
join her for a bridge games with the Matthews.
I am pleased to report that the look and feel of the screen are pretty much
what I want and pretty much at least resembles the instrumentation in my Model
S. It's all functional and has pretty good response.
So I get a glass of tea and light up a Camel. It's 5:43 on Saturday evening and
I haven't shot a second of video as yet. But I do have it calculating a
plausible remaining range, and doing the state of charge thing and the amphours
used and kilowatts used and it is all hanging together. I can put it in any
gear from EITHER the PowerkeyPro 2400 panel or the touchscreen. Creep on/off
demonstrably works. Regen increase and decrease. My trip meter works. The
odometer resets. The SOC resets at a touch. And I finally have the colors right
on the very strange logarithmic scale Tesla uses to show power output or input
on the right side of the dial. Life is good. But I'm going to have to shut down
and go to a bridge game.
POP. BANG.
What was that? Sounded like somebody banging on one of the closed garage doors.
BANG POP POP. What the hell?
I went into the next room to see who was banging on the door, but as I reached
to open the door, the POP POP BANG sounded again but BEHIND me. I walked over
to the Better Place battery pack from the Renault Influenza that we use on the
OEM components test bench. BANG POP POP. These are actually pretty loud. What
the......?????
This pack was right out of the cargo container and we never even attempted a
bottom balance. We were only going to use it for testing chargers and DC-DC
converters and the UQM test bench. But as the result of one of our assclowns
playing around with the bench while I wasn't in the shop, it had drained down
very slowly overnight to a very low level.
It seemed to charge back up ok. But never quite got to full charge. So I had
hooked it up earlier in the afternoon to bring it up some more.
I quickly shut off the charger and cut off the contactors. But it continued to
BANG and POP irregularly. I can't leave to go to bridge with it like this I'm
thinking. As there had been several of these "no show" moments in the past few
weeks where I threw my wife under the bus with regards to one plan or another,
this was not really good. I can't believe I'm doing this again.
Suddenly the pack begins to issue the familiar white smoke - just a bit at
first, then more. The pack weighs 450 lbs, and the fork lift is at the other
end of the building. I went over to the wall water spigot, glad I had a couple
hundred feet of hose there to water our grass. No hose. Assclown somewhere had
made command level decision to move it down to the basement in the other
building apparently. There was a hose, but it was four feet long.
By this time the white smoke was coming out pretty good. I don't know why, but
I was curious what the temps were. So I grabbed an infrared gun and shot all
the cells. Most were warmish in the 35-40C range but there were two sitting at
95C. Not good.
Suddenly the pack spewed a spear of sparks and flame about six feet straight
out the front - right where I had been a moment before. And then it exploded
into a massive fireball shooting flames up to the ceiling with such velocity
that they splashed laterally from there.
It would have made excellent video I must say. At this point, I'm out of
altitude, airspeed, and ideas all at the same time. I jumped in the Tesla and
backed it out of the building. For some reason, I closed teh garage door after
I was out, as I always do. I then had a positively exasperating wrestling match
with the car for control of my cell phone to dial 911. I mean this car wanted
to do ANYTHING except dial the phone. It played some Kriss Christopherson "Help
Me Make it through the Night" (right) and some Rod Stewart. But it must have
taken me three or four minutes to get it to dial 3 digits.
Cape Girardeau actually has an excellent fire department and they have a
station about three blocks away. They were there within five minutes. I opened
teh garage door to let them in and it seemed the flames had died off - I guess
I had inadvertently shut off the oxygen. But black billowing clouds of smoke
poured out of the building.
They quickly got it under control. But the way Fire Departments work to put out
fires, they mostly disassemble the building. They cut power lines, climb up on
the roof, open it up, and of course dump several shiploads of water down into
the space. It looked like they were cutting the cables on the roof connecting
the solar system, the air conditioning condensor, and anything else in sight.
The $30,000 roof I had just installed two years ago was torn up and opened up
with chain saws. Yeah, they're that good.
What did I do? Well, I answered a few questions from the fire department
investigator but that was pretty short when he found out I don't HAVE any
insurance. We have a lot of buildings around here go up in flames with a LOT of
insurance on them. I don't carry any. So I'm pretty much off the prospective
arson prosecution list - shortening the interview rather quickly.
So I went home to play bridge. Brian Perry kind of hung out to try to secure
the building in the aftermath. But I went home and played bridge.
Not very well I fear. We got clobbered. I guess my head wasn't into the game
but the wife, as almost always, was very understanding of my poor bidding and
play.
It's Sunday morning. I guess I'll go down and see what's left. But we have no
roof in rainy November. And no electricity at all - they pulled the meters of
course. My OEM components test bench is no doubt gone and I actually had a
special bench spruced up on one side with all the various connectors (rather
expensive connectors) needed to use these components. I had spent over a year
tracking all that down. No hope. It was too close to the battery pack.
I firmly believe that all happens for a reason and ultimately for the good. But
this one will be interesting to see play out.
It's a very dark, though sunny Sunday morning.
Enviado desde mi iPhone
> El 08/11/2015, a las 1:02 p.m., Michael Ross via EV <ev@lists.evdl.org>
> escribió:
>
> Hi Paul,
>
> I am not sure CALB should be qualified as high quality particularly if they
> are vintage; but it is very hard to tell, because testing methods have been
> inadequate for all cells until the last couple years. I would say
> Panasonic for sure are high qualify at least relative to the universe of Li
> ion. Maybe LG? They seem to be trying hard and working smart.
>
> Little cylindrical cells have form factor advantages. The large prismatics
> can't take the volumetric changes as well over time. It is mechanical
> issues that are the primary cause of grief with respect to degradation over
> time, not the basic chemistry and configuration itself. Clearly electrolyte
> composition is important, but this is a newer frontier.
>
> Good testing that provides useful results in a relatively short time will
> help everyone.
>
> Mike
>
>> On Sun, Nov 8, 2015 at 2:13 PM, paul dove <dov...@bellsouth.net> wrote:
>>
>> I didn't address the self-discharge on purpose. People will believe what
>> they want.
>>
>> However, I had a pack of Calb 60Ah cells in my garage that I had drained
>> to bottom balance. I had forgotten about them and it had been over a year
>> since I did this. We were having the conversation about self discharge on
>> this web site and I got worried they were correct after I posted the
>> article on here talking about self discharge in Li Ion cells. So, I measure
>> the voltage on all the cells and found a couple that were down to 1.8 volts
>> and then I thought they were correct.
>>
>> i took the cells and charged them. It was weird the voltage went allover
>> the place but I didn't give up. I discharged them and charged them and the
>> first time it had 25 Ah. the second time 45Ah and so I cycled them about 5
>> times and every cell came up to full capacity. I know because I have the
>> capacity sheet from CALB and the all have serial numbers.
>>
>> This inadvertent experiment confirmed the findings of the paper that I
>> read. Saying that self discharge is manifested in a temporary loss of
>> capacity that can be recovered by cycling the cells.
>>
>> Now, not all the cells exhibited this behavior. There were three cells out
>> of a hundred that did this. The rest of them were fine.
>>
>> ------------------------------
>> *From:* Michael Ross <michael.e.r...@gmail.com>
>> *To:* paul dove <dov...@bellsouth.net>; Electric Vehicle Discussion List <
>> ev@lists.evdl.org>
>> *Sent:* Sunday, November 8, 2015 12:18 PM
>>
>> *Subject:* Re: [EVDL] Rickard's EVTV let the smoke out> overcharged pack
>> fire blew up
>>
>> I think the self discharge complaint is growing less all the time - with
>> good quality cells. But really large packs beg prudence. A golf cart
>> packs, like Jack sells which will be operated by non EV types, gets real
>> benefit from his bottom balancing and sealing. The little 10AH 48V packs
>> used in light EVs and bikes are a analogous - small, operated by the
>> unwashed.
>>
>> Whatever is done, a really dependable charge cut off function must be part
>> of any system.
>>
>> Our ability to evaluate cell quality, and BMS quality and function is
>> still suspect (particularly for the cash strapped DIYer; as opposed to a
>> large company with real money to command action) so I expect this argument
>> to continue, and it should.
>>
>>
>>
>> On Sun, Nov 8, 2015 at 1:03 PM, paul dove via EV <ev@lists.evdl.org>
>> wrote:
>>
>> There is no evidence thus far to support that theory.
>> It could have been a pack he uses to power his bench or one he was
>> charging to put in a car.
>> He does all sorts of crazy experiments like test the sag while pulling
>> 1000 amps.
>> From the article it didn't sound like it was in a car.
>>
>> From: Bill Dube via EV <ev@lists.evdl.org>
>> To: EVDL Administrator <evp...@drmm.net>; Electric Vehicle Discussion
>> List <ev@lists.evdl.org>
>> Sent: Sunday, November 8, 2015 11:51 AM
>> Subject: Re: [EVDL] Rickard's EVTV let the smoke out> overcharged pack
>> fire blew up
>>
>> This fellow is the flag bearer for the small anti-BMS movement.
>> A pack fire (in this instance a pack explosion) was predictable and
>> unfortunately inevitable. I'm glad that no one was injured.
>>
>> Pack fires do rarely occur even under ideal circumstances, ("The world
>> is an imperfect place, screws fall out") but this pack fire was simply a
>> matter of time, like a ticking bomb simply waiting to go off. As I
>> understand it, he has had less dramatic pack fires before.
>>
>> It would be a positive outcome of this tragic incident if this were to
>> change a few minds in this minority anti-BMS crowd on the need for a
>> BMS. Unfortunately, the anti-BMS crowd doesn't understand, (or choose to
>> ignore the advice of the countless experts that /do/ understand,) that
>> variable self discharge exists in li-ion cells. It is a very real
>> problem in maintaining battery balance in a high-voltage battery pack.
>> This is why folks go through the trouble and expense of qualifying and
>> buying a BMS for each and every high-voltage li-ion battery pack.
>>
>> Bill Dube'
>>
>>
>>
>>> On 11/8/2015 3:45 AM, EVDL Administrator via EV wrote:
>>> Not to cause controversy, but do I recall right that Jack Rickard is one
>> of
>>> the guys who've said that lithium batteries without BMSes never catch
>> fire?
>>> Or was that someone else?
>>>
>>> Certainly that's a claim I've heard, on the EVDL and elsewhere.
>>>
>>> David Roden - Akron, Ohio, USA
>>> EVDL Administrator
>>>
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>>>
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>>
>> --
>> To invent, you need a good imagination and a pile of junk.
>> Thomas A. Edison
>> <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html>
>>
>> A public-opinion poll is no substitute for thought.
>> *Warren Buffet*
>>
>> Michael E. Ross
>> (919) 585-6737 Land
>> (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google
>> Phone
>> (919) 600-2892 Cell
>>
>> michael.e.r...@gmail.com
>> <michael.e.r...@gmail.com>
>
>
> --
> To invent, you need a good imagination and a pile of junk.
> Thomas A. Edison
> <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html>
>
> A public-opinion poll is no substitute for thought.
> *Warren Buffet*
>
> Michael E. Ross
> (919) 585-6737 Land
> (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone
> (919) 600-2892 Cell
>
> michael.e.r...@gmail.com
> <michael.e.r...@gmail.com>
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