Re: Tried to burn up my battery pack, car, and garage today

["Joe Smalley" <joes@worldfront.com>]

I have posted the schematic at http://www.manzanitamicro.com/chreg3.kdf.

I got lazy and just printed it to the Kinko's file prep tool because it was
too big to conveniently convert to a GIF. When I get some time, I can
convert it to a GIF.

This schematic has more voltage capability than the one I built. This one
will go to 350 volts whereas the one I built would only go to 200 volts. Be
advised that no one has built one of these yet. There may be errors in the
schematic that we don't know about. Be careful and check everything before
connecting it to your battery and charger.

The circuit connection is simple:
The top left connector goes to the charger positive.
The top right connector goes to battery positive.
The bottom connector goes to battery and charger negative.
The pot adjusts the voltage cutout. As it is in the schematic the control
goes from about 100 volts to about 200 volts. Raise R6 if you want it to go
higher.

This circuit was designed three years ago and we currently have no plans to
do anything with it. We have no plans to support it. If you build one, we
may help troubleshoot it if time allows. If you find an error in the
schematic, I will correct the image.

Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
joes@worldfront.com



----- Original Message -----
From: "Joe Smalley" <joes@worldfront.com>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, July 30, 2002 11:06 PM
Subject: Re: Tried to burn up my battery pack, car, and garage today


> I have a gizmo I built several years ago for just this type of situation.
It
> is an SCR with a trigger circuit that turns the SCR on when the battery
> voltage is below a setpoint. It was designed to handle 20 amps coming out
of
> a charger such as yours. When I built it, I wired it with only 14 gauge
wire
> so it won't handle 20 amps as is. If you are interested, I can post the
> schematic or take it to Woodburn for you.
>
> Joe Smalley
> Rural Kitsap County WA
> Fiesta 48 volts
> NEDRA 48 volt street conversion record holder
> joes@worldfront.com
>
>
> ----- Original Message -----
> From: "John Bryan" <jbryan4@mindspring.com>
> To: <ev@listproc.sjsu.edu>
> Sent: Tuesday, July 30, 2002 3:22 PM
> Subject: Tried to burn up my battery pack, car, and garage today
>
>
> >
> > I guess it had to happen sometime. Whenever a human is
> > involved you know that things will eventually go wrong. I got
> > home from the store around noon and decided to juice up my
> > car quickly with my Badass-Boy Charger. It's similar to a
> > Bad Boy Charger, only it runs on 220 and has the ability to
> > take out my car's pack. The car was only down 8.5 Ah, so I
> > planned on only leaving it plugged in for about 20 minutes
> > and then letting the onboard system take it from there. I
> > checked the E-meter and saw 18 amps flowing into the 192 Volt
> > pack before I left and basically didn't come back.
> >
> > This pack is made up of 16 Optima YellowTops that
> > are 6 years old this September. They have powered my trusted
> > daily ride for the last 5 years. The problem today is that I
> > was really tired from getting awaken all night by exploding
> > powerline transformers. My stupid alarm clock can't handle
> > the noise, so I got up and reset it at 2:30 and again at
> > around 5. So I was really tired when I sat down and started
> > having lunch - already having forgotten all about the car.
> >
> > After I finished eating I sat down in a really
> > comfortable chair and started reading a fine book. Meanwhile,
> > my battery pack was heading for record voltages as it continued
> > rapidly charging even after becoming completely filled. As the
> > batteries eventually started into full thermal runaway, I closed
> > the book, set it down, and settled into a nice peaceful and
> > restful sleep. I woke up a couple of times, only to go right back
> > to my badly needed slumber. Suddenly, I cracked my eyes barely open,
> > then I...remembered. I felt my eyes go wide like saucers and I just
> > literally flew out of the chair and ran from the house.
> >
> > On my way to the garage, I came to the Badass Boy Charger
> > about halfway between the house and the garage. After yanking
> > the plug and holding the cord that led to the garage, I wondered
> > what I would find at the other end. The car had been on charge
> > for 2 hours and I fully expected to find a terrible mess and a
> > ruined pack. I was amazed to find that although the batteries
> > were all very hot, not a single one of them had vented. I'm sure
> > they were extremely close though. I started sniffing around to
> > see if I could detect any telltale aromas, but all that I could
> > smell was clean, hot, yellow plastic. They were around 110 deg.
> >
> > As they cooled down I kept an eye on them and put them
> > on float with the onboard system holding each module at 13.8 Volts.
> > I have the feeling they are going to live! If anything they seem
> > to be even better than before, judging from the extremely long
> > off times that I'm seeing with the chargers. Times that I haven't
> > seen for a couple of years or so. I consider myself very lucky
> > and feel that I came just as close to that line as I could without
> > stepping over it. It'll be interesting to see how the pack performs
> > on its next run. The solution to this is obviously an automatic
> > shutoff, another of those things getting higher and higher on my
> > list of things to do.
> >
> > Seeya,
> > John
> >
>