data logger request

classic Classic list List threaded Threaded
30 messages Options
12
Reply | Threaded
Open this post in threaded view
|

data logger request

fred ungewitter
I'll be shifting from lead-acid to lithium iron phosphate in the near future.
I've had a PakTrakr on the pack since day one and it's been rather convenient to
know that I'm not damaging my pack as I drive and also to know that my charging
sequence is working properly.

I've done some searching on the wide world of the tubes known as the internet
and only managed to muddy the waters of my alleged mind.

Is there an affordable product on the market that will connect to 40 LiFePO4
cells in a pack and monitor and record the voltages and current for the pack,
cell-for-cell?


I realize that it might seem obsessive to want such a product/device, but my
experience so far has been useful and the additional expense seems justified in
my opinion.


fred ungewitter
daytona beach, fl
gizmo ev
rav4ev
sbu v2.0



     
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/c3dd767c/attachment.html 
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

Zeke Yewdall
Finding dataloggers on line is quite difficult, I've found... given that
they are usually sold to research and development labs or departments,
rather than on-line buyers -- so calling them and talking to a development
engineer there is sometimes all you can do -- and they expect you have a
large budget.  I've done enough datalogging, in labs, to know that to use
the typical equipment they are used to using to monitor 40 batteries would
be $2000+ ...  building your own from a simple USB enabled datalogger and a
multiplexer could probably be much cheaper, if you've got the skills.

On Mon, Jan 24, 2011 at 11:02 AM, fred <[hidden email]> wrote:

> I'll be shifting from lead-acid to lithium iron phosphate in the near
> future.
> I've had a PakTrakr on the pack since day one and it's been rather
> convenient to
> know that I'm not damaging my pack as I drive and also to know that my
> charging
> sequence is working properly.
>
> I've done some searching on the wide world of the tubes known as the
> internet
> and only managed to muddy the waters of my alleged mind.
>
> Is there an affordable product on the market that will connect to 40
> LiFePO4
> cells in a pack and monitor and record the voltages and current for the
> pack,
> cell-for-cell?
>
>
> I realize that it might seem obsessive to want such a product/device, but
> my
> experience so far has been useful and the additional expense seems
> justified in
> my opinion.
>
>
> fred ungewitter
> daytona beach, fl
> gizmo ev
> rav4ev
> sbu v2.0
>
>
>
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/c3dd767c/attachment.html
> _______________________________________________
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/cf14d745/attachment.html 
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

Evan Tuer
In reply to this post by fred ungewitter
On Mon, Jan 24, 2011 at 6:02 PM, fred <[hidden email]> wrote:

> Is there an affordable product on the market that will connect to 40 LiFePO4
> cells in a pack and monitor and record the voltages and current for the pack,
> cell-for-cell?

My BMS (also 40 cells by coincidence) spits out this data
continuously.  To record it you just need to plug in a computer of
some sort, via serial data.  I'm sure others are similar.

I don't actually bother though :)

_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

damon henry
In reply to this post by fred ungewitter

It sounds like what I see John Wayland using on the White Zombie at the drag strip might fit the bill for you.  You can get details and pricing on the Manzanita Micro website http://www.manzanitamicro.com.  Here is what they have listed as their feature set.
KEY FEATURES· Real time voltage monitoring of 4 to 8 lithium cells· Real time temperature sensing of up to 8 external temp sensors· Additional temperature sensor included on BMS module’s heat sink· Small size is less than 1 inch thick and 7 inches long by 2.4 inches wide· Quick automatic cell equalization and balancing with high and low voltage on board indicators and outputs to the charger· Two high speed real-time warning lines which can be relay buffered for external use· All BMS modules connect together using readily available RJ cable· BMS easily connects to a PC using the DT USB adapter (Dongle/Terminator sold separately)· Free Windows based scanner and command software available for download atwww.manzanitamicro.com in the download section under MK3 Reg Support.· All commands are easily entered and read in simple ASCII text· Easy user adjustable min and max voltage parameters allow flexibility for various types of lithium cells from 1.75 to 5.5 volts per cell· Each BMS board can bypass up to 2.5 amps per cell equating to fast charging and equalization of unbalanced cells· Dual RJ reg bus ports for easy connection to the charger or other BMS units in a simple daisy chain fashion· Self regulating thermal protection and feedback to Manzanita Micro Chargers· Built-in active variable speed 12V DC fan control output on each BMS unit. The fan settings can be viewed and changed using the software found on our website· Large heat spreader is totally isolated from the cells and is already threaded for easy mounting to a larger heat sink.· Each unit can dissipate up to 110 watts

> Date: Mon, 24 Jan 2011 10:02:32 -0800
> From: [hidden email]
> To: [hidden email]
> Subject: [EVDL] data logger request
> Is there an affordable product on the market that will connect to 40 LiFePO4
> cells in a pack and monitor and record the voltages and current for the pack,
> cell-for-cell?

     
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/6e664822/attachment.html 
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

Zeke Yewdall
In reply to this post by Evan Tuer
Having the datalogging integrated into the BMS makes alot of sense... you've
already got the BMS looking at each cell, so why not use that data for more
than just running the BMS instead of having duplicate equipment of a
separate datalogger.

What BMS do you have?

Z

On Mon, Jan 24, 2011 at 11:25 AM, Evan Tuer <[hidden email]> wrote:

> On Mon, Jan 24, 2011 at 6:02 PM, fred <[hidden email]> wrote:
>
> > Is there an affordable product on the market that will connect to 40
> LiFePO4
> > cells in a pack and monitor and record the voltages and current for the
> pack,
> > cell-for-cell?
>
> My BMS (also 40 cells by coincidence) spits out this data
> continuously.  To record it you just need to plug in a computer of
> some sort, via serial data.  I'm sure others are similar.
>
> I don't actually bother though :)
>
> _______________________________________________
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/b0c7abe5/attachment.html 
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

wjdennis@qwest.net
In reply to this post by fred ungewitter
Well, I've been working on something for the past few months, but I haven't
said anything about it here on the EVDL because it might seem a silly way
to go.  I've actually got a prototype system running on my workbench right
now that uses USB computer mice to send cell voltage info to a laptop.
Each mouse monitors the voltage of 4 cells, using the three mouse buttons
and the scroll wheel.  

Basically, I removed the microswitches on each mouse button/wheel and
replaced them with optos.  A PIC chip at each cell measures the voltage
every few seconds, then closes/opens the opto to simulate mouse clicks.  A
Java program running on the PC displays reads to mouse clicks on the USB
ports to display real-time info and record the history.

My goal was that components would cost less than $1.00US per cell.  Each
mouse cost 99 cents and measures four cells, so it was like buying a
pre-made circuit for 25 cents per cell.  I'm trying to find a way to
increase it to 6 cells per mouse, using some of the chip's other
functionality, which would make it even cheaper per cell.  Peripheral stuff
(capacitors, optos, resistors) adds up to about 60 cents per cell.  

Hey, I told you it was silly.

Bill    

Original Message:
-----------------
From: Zeke Yewdall [hidden email]
Date: Mon, 24 Jan 2011 11:10:19 -0700
To: [hidden email]
Subject: Re: [EVDL] data logger request


Finding dataloggers on line is quite difficult, I've found... given that
they are usually sold to research and development labs or departments,
rather than on-line buyers -- so calling them and talking to a development
engineer there is sometimes all you can do -- and they expect you have a
large budget.  I've done enough datalogging, in labs, to know that to use
the typical equipment they are used to using to monitor 40 batteries would
be $2000+ ...  building your own from a simple USB enabled datalogger and a
multiplexer could probably be much cheaper, if you've got the skills.

On Mon, Jan 24, 2011 at 11:02 AM, fred <[hidden email]> wrote:

> I'll be shifting from lead-acid to lithium iron phosphate in the near
> future.
> I've had a PakTrakr on the pack since day one and it's been rather
> convenient to
> know that I'm not damaging my pack as I drive and also to know that my
> charging
> sequence is working properly.
>
> I've done some searching on the wide world of the tubes known as the
> internet
> and only managed to muddy the waters of my alleged mind.
>
> Is there an affordable product on the market that will connect to 40
> LiFePO4
> cells in a pack and monitor and record the voltages and current for the
> pack,
> cell-for-cell?
>
>
> I realize that it might seem obsessive to want such a product/device, but
> my
> experience so far has been useful and the additional expense seems
> justified in
> my opinion.
>
>
> fred ungewitter
> daytona beach, fl
> gizmo ev
> rav4ev
> sbu v2.0
>
>
>
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
>
http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/c3dd767c/attac
hment.html
> _______________________________________________
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/cf14d745/attac
hment.html
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev


--------------------------------------------------------------------
mail2web - Check your email from the web at
http://link.mail2web.com/mail2web



_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

fred ungewitter
In reply to this post by fred ungewitter
Zeke, unfortunately, I don't have those skills. I've read quite a few articles
about Arduino, BasicStamp and the like and wish I had the skill set to build
something based on these amazing developments in microcomputers.

Evan, I'll echo Zeke's question and ask what you have, since there was no
reference in the message. Something you constructed yourself? Data storage on SD
card would be better than constant streaming to a connected PC, allowing for
bulk dumps at the end of a run or end of a charge sequence.

Damon, even though I plan to not have a BMS, after all the posts and references
here, I could tolerate one if I can get the data I desire. I found the link on
the site you've noted. Eleven hundred dollars for 40 cells, quite a bundle. The
BMS seems excessive overall, though, again based on the information posted here
about BMS and LiFePO4 packs.
------------------------------


From: Zeke Yewdall <[hidden email]>

Finding dataloggers on line is quite difficult, I've found... given that
they are usually sold to research and development labs or departments,
rather than on-line buyers -- so calling them and talking to a development
engineer there is sometimes all you can do -- and they expect you have a
large budget.  I've done enough datalogging, in labs, to know that to use
the typical equipment they are used to using to monitor 40 batteries would
be $2000+ ...  building your own from a simple USB enabled datalogger and a
multiplexer could probably be much cheaper, if you've got the skills.

From: Evan Tuer <[hidden email]>

My BMS (also 40 cells by coincidence) spits out this data
continuously.  To record it you just need to plug in a computer of
some sort, via serial data.  I'm sure others are similar.

I don't actually bother though :)

From: damon henry <[hidden email]>


It sounds like what I see John Wayland using on the White Zombie at the drag
strip might fit the bill for you.  You can get details and pricing on the
Manzanita Micro website http://www.manzanitamicro.com.  Here is what they have
listed as their feature set.
KEY FEATURES? Real time voltage monitoring of 4 to 8 lithium cells? Real time
temperature sensing of up to 8 external temp sensors? Additional temperature
sensor included on BMS module?s heat sink? Small size is less than 1 inch thick
and 7 inches long by 2.4 inches wide? Quick automatic cell equalization and
balancing with high and low voltage on board indicators and outputs to the
charger? Two high speed real-time warning lines which can be relay buffered for
external use? All BMS modules connect together using readily available RJ cable?
BMS easily connects to a PC using the DT USB adapter (Dongle/Terminator sold
separately)? Free Windows based scanner and command software available for
download atwww.manzanitamicro.com in the download section under MK3 Reg
Support.? All commands are easily entered and read in simple ASCII text? Easy
user adjustable min and max voltage parameters allow flexibility for various
types of lithium cells from 1.75 to 5.5 volts per cell? Each BM!
S board can bypass up to 2.5 amps per cell equating to fast charging and
equalization of unbalanced cells? Dual RJ reg bus ports for easy connection to
the charger or other BMS units in a simple daisy chain fashion? Self regulating
thermal protection and feedback to Manzanita Micro Chargers? Built-in active
variable speed 12V DC fan control output on each BMS unit. The fan settings can
be viewed and changed using the software found on our website? Large heat
spreader is totally isolated from the cells and is already threaded for easy
mounting to a larger heat sink.? Each unit can dissipate up to 110 watts
From: Zeke Yewdall <[hidden email]>

Having the datalogging integrated into the BMS makes alot of sense... you've
already got the BMS looking at each cell, so why not use that data for more
than just running the BMS instead of having duplicate equipment of a
separate datalogger.

What BMS do you have?

**********************************

End of Compiled Messages
__________________________



     
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/e45f2b88/attachment.html 
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

corbin dunn
In reply to this post by fred ungewitter
Hi Fred,
The Elithion Lithiumate BMS will do this. I'm using it for my new EV, and I like it a lot. Affordable is relative...it is probably $1000-$1200. Depending on the cost of the batteries that is quite affordable.

corbin

On Jan 24, 2011, at 10:02 AM, fred wrote:

> I'll be shifting from lead-acid to lithium iron phosphate in the near future.
> I've had a PakTrakr on the pack since day one and it's been rather convenient to
> know that I'm not damaging my pack as I drive and also to know that my charging
> sequence is working properly.
>
> I've done some searching on the wide world of the tubes known as the internet
> and only managed to muddy the waters of my alleged mind.
>
> Is there an affordable product on the market that will connect to 40 LiFePO4
> cells in a pack and monitor and record the voltages and current for the pack,
> cell-for-cell?
>
>
> I realize that it might seem obsessive to want such a product/device, but my
> experience so far has been useful and the additional expense seems justified in
> my opinion.
>
>
> fred ungewitter
> daytona beach, fl
> gizmo ev
> rav4ev
> sbu v2.0
>
>
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/4d862258/attachment.html 
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

damon henry
In reply to this post by fred ungewitter

> Damon, even though I plan to not have a BMS, after all the posts and references
> here, I could tolerate one if I can get the data I desire. I found the link on
> the site you've noted. Eleven hundred dollars for 40 cells, quite a bundle. The
> BMS seems excessive overall, though, again based on the information posted here
> about BMS and LiFePO4 packs.
> ------------------------------

Ok, wasn't sure what your price point was.  Seems like you could use your paktraker that you are already familiar with.  It would not give you individual cell data, but you could wire one sensor across multiple cells and still get some pretty useful data.
damon    
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/f35539b2/attachment.html 
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

Zeke Yewdall
In reply to this post by wjdennis@qwest.net
Silly it may be, but if it works, it sounds like it's a pretty inventive way
to use cheap mass produced USB components to do it...

Z

On Mon, Jan 24, 2011 at 1:54 PM, [hidden email] <[hidden email]>wrote:

> Well, I've been working on something for the past few months, but I haven't
> said anything about it here on the EVDL because it might seem a silly way
> to go.  I've actually got a prototype system running on my workbench right
> now that uses USB computer mice to send cell voltage info to a laptop.
> Each mouse monitors the voltage of 4 cells, using the three mouse buttons
> and the scroll wheel.
>
> Basically, I removed the microswitches on each mouse button/wheel and
> replaced them with optos.  A PIC chip at each cell measures the voltage
> every few seconds, then closes/opens the opto to simulate mouse clicks.  A
> Java program running on the PC displays reads to mouse clicks on the USB
> ports to display real-time info and record the history.
>
> My goal was that components would cost less than $1.00US per cell.  Each
> mouse cost 99 cents and measures four cells, so it was like buying a
> pre-made circuit for 25 cents per cell.  I'm trying to find a way to
> increase it to 6 cells per mouse, using some of the chip's other
> functionality, which would make it even cheaper per cell.  Peripheral stuff
> (capacitors, optos, resistors) adds up to about 60 cents per cell.
>
> Hey, I told you it was silly.
>
> Bill
>
> Original Message:
> -----------------
> From: Zeke Yewdall [hidden email]
> Date: Mon, 24 Jan 2011 11:10:19 -0700
> To: [hidden email]
> Subject: Re: [EVDL] data logger request
>
>
> Finding dataloggers on line is quite difficult, I've found... given that
> they are usually sold to research and development labs or departments,
> rather than on-line buyers -- so calling them and talking to a development
> engineer there is sometimes all you can do -- and they expect you have a
> large budget.  I've done enough datalogging, in labs, to know that to use
> the typical equipment they are used to using to monitor 40 batteries would
> be $2000+ ...  building your own from a simple USB enabled datalogger and a
> multiplexer could probably be much cheaper, if you've got the skills.
>
> On Mon, Jan 24, 2011 at 11:02 AM, fred <[hidden email]> wrote:
>
> > I'll be shifting from lead-acid to lithium iron phosphate in the near
> > future.
> > I've had a PakTrakr on the pack since day one and it's been rather
> > convenient to
> > know that I'm not damaging my pack as I drive and also to know that my
> > charging
> > sequence is working properly.
> >
> > I've done some searching on the wide world of the tubes known as the
> > internet
> > and only managed to muddy the waters of my alleged mind.
> >
> > Is there an affordable product on the market that will connect to 40
> > LiFePO4
> > cells in a pack and monitor and record the voltages and current for the
> > pack,
> > cell-for-cell?
> >
> >
> > I realize that it might seem obsessive to want such a product/device, but
> > my
> > experience so far has been useful and the additional expense seems
> > justified in
> > my opinion.
> >
> >
> > fred ungewitter
> > daytona beach, fl
> > gizmo ev
> > rav4ev
> > sbu v2.0
> >
> >
> >
> >
> > -------------- next part --------------
> > An HTML attachment was scrubbed...
> > URL:
> >
>
> http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/c3dd767c/attac
> hment.html
> > _______________________________________________
> > | REPLYING: address your message to [hidden email] only.
> > | Multiple-address or CCed messages may be rejected.
> > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> > | OTHER HELP: http://evdl.org/help/
> > | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
> >
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
>
> http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/cf14d745/attac
> hment.html
> _______________________________________________
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
>
> --------------------------------------------------------------------
> mail2web - Check your email from the web at
> http://link.mail2web.com/mail2web
>
>
>
> _______________________________________________
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/d3f33414/attachment.html 
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

Peter Gabrielsson
In reply to this post by wjdennis@qwest.net
Cute solution. How about the control PCB out of a keyboard, you get
105buttons to play with for $5

On Mon, Jan 24, 2011 at 12:54 PM, [hidden email] <[hidden email]> wrote:

> Well, I've been working on something for the past few months, but I haven't
> said anything about it here on the EVDL because it might seem a silly way
> to go.  I've actually got a prototype system running on my workbench right
> now that uses USB computer mice to send cell voltage info to a laptop.
> Each mouse monitors the voltage of 4 cells, using the three mouse buttons
> and the scroll wheel.
>
> Basically, I removed the microswitches on each mouse button/wheel and
> replaced them with optos.  A PIC chip at each cell measures the voltage
> every few seconds, then closes/opens the opto to simulate mouse clicks.  A
> Java program running on the PC displays reads to mouse clicks on the USB
> ports to display real-time info and record the history.
>
> My goal was that components would cost less than $1.00US per cell.  Each
> mouse cost 99 cents and measures four cells, so it was like buying a
> pre-made circuit for 25 cents per cell.  I'm trying to find a way to
> increase it to 6 cells per mouse, using some of the chip's other
> functionality, which would make it even cheaper per cell.  Peripheral stuff
> (capacitors, optos, resistors) adds up to about 60 cents per cell.
>
> Hey, I told you it was silly.
>
> Bill
>
> Original Message:
> -----------------
> From: Zeke Yewdall [hidden email]
> Date: Mon, 24 Jan 2011 11:10:19 -0700
> To: [hidden email]
> Subject: Re: [EVDL] data logger request
>
>
> Finding dataloggers on line is quite difficult, I've found... given that
> they are usually sold to research and development labs or departments,
> rather than on-line buyers -- so calling them and talking to a development
> engineer there is sometimes all you can do -- and they expect you have a
> large budget.  I've done enough datalogging, in labs, to know that to use
> the typical equipment they are used to using to monitor 40 batteries would
> be $2000+ ...  building your own from a simple USB enabled datalogger and a
> multiplexer could probably be much cheaper, if you've got the skills.
>
> On Mon, Jan 24, 2011 at 11:02 AM, fred <[hidden email]> wrote:
>
>> I'll be shifting from lead-acid to lithium iron phosphate in the near
>> future.
>> I've had a PakTrakr on the pack since day one and it's been rather
>> convenient to
>> know that I'm not damaging my pack as I drive and also to know that my
>> charging
>> sequence is working properly.
>>
>> I've done some searching on the wide world of the tubes known as the
>> internet
>> and only managed to muddy the waters of my alleged mind.
>>
>> Is there an affordable product on the market that will connect to 40
>> LiFePO4
>> cells in a pack and monitor and record the voltages and current for the
>> pack,
>> cell-for-cell?
>>
>>
>> I realize that it might seem obsessive to want such a product/device, but
>> my
>> experience so far has been useful and the additional expense seems
>> justified in
>> my opinion.
>>
>>
>> fred ungewitter
>> daytona beach, fl
>> gizmo ev
>> rav4ev
>> sbu v2.0
>>
>>
>>
>>
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>> URL:
>>
> http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/c3dd767c/attac
> hment.html
>> _______________________________________________
>> | REPLYING: address your message to [hidden email] only.
>> | Multiple-address or CCed messages may be rejected.
>> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
>> | OTHER HELP: http://evdl.org/help/
>> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/cf14d745/attac
> hment.html
> _______________________________________________
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
>
> --------------------------------------------------------------------
> mail2web - Check your email from the web at
> http://link.mail2web.com/mail2web
>
>
>
> _______________________________________________
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>



--
www.electric-lemon.com

_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

Matt Lacey
In reply to this post by damon henry
If you are going to use the paktrakr with lithium cells,
make sure the first "12v" lead isn't connected to the actual pack.

The power for the module comes from the first battery, pulling it outta
balance relative to the rest of the pack.

Matt

----- Original Message -----
From: "damon henry" <[hidden email]>
To: "EV List" <[hidden email]>
Sent: Tuesday, January 25, 2011 5:44 AM
Subject: Re: [EVDL] data logger request


>
>> Damon, even though I plan to not have a BMS, after all the posts and
>> references
>> here, I could tolerate one if I can get the data I desire. I found the
>> link on
>> the site you've noted. Eleven hundred dollars for 40 cells, quite a
>> bundle. The
>> BMS seems excessive overall, though, again based on the information
>> posted here
>> about BMS and LiFePO4 packs.
>> ------------------------------
>
> Ok, wasn't sure what your price point was.  Seems like you could use your
> paktraker that you are already familiar with.  It would not give you
> individual cell data, but you could wire one sensor across multiple cells
> and still get some pretty useful data.
> damon
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/f35539b2/attachment.html
> _______________________________________________
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1191 / Virus Database: 1435/3399 - Release Date: 01/23/11
>

_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

Jack Murray
In reply to this post by wjdennis@qwest.net
That is quite clever Bill!

If you have the ability to assemble and program PICs,
there are many options.  

--- On Mon, 1/24/11, [hidden email] <[hidden email]> wrote:

> From: [hidden email] <[hidden email]>
> Subject: Re: [EVDL] data logger request
> To: [hidden email]
> Date: Monday, January 24, 2011, 12:54 PM
> Well, I've been working on something
> for the past few months, but I haven't
> said anything about it here on the EVDL because it might
> seem a silly way
> to go.  I've actually got a prototype system running
> on my workbench right
> now that uses USB computer mice to send cell voltage info
> to a laptop.
> Each mouse monitors the voltage of 4 cells, using the three
> mouse buttons
> and the scroll wheel. 
>
> Basically, I removed the microswitches on each mouse
> button/wheel and
> replaced them with optos.  A PIC chip at each cell
> measures the voltage
> every few seconds, then closes/opens the opto to simulate
> mouse clicks.  A
> Java program running on the PC displays reads to mouse
> clicks on the USB
> ports to display real-time info and record the history.
>
> My goal was that components would cost less than $1.00US
> per cell.  Each
> mouse cost 99 cents and measures four cells, so it was like
> buying a
> pre-made circuit for 25 cents per cell.  I'm trying to
> find a way to
> increase it to 6 cells per mouse, using some of the chip's
> other
> functionality, which would make it even cheaper per
> cell.  Peripheral stuff
> (capacitors, optos, resistors) adds up to about 60 cents
> per cell. 
>
> Hey, I told you it was silly.
>
> Bill     
>
> Original Message:
> -----------------
> From: Zeke Yewdall [hidden email]
> Date: Mon, 24 Jan 2011 11:10:19 -0700
> To: [hidden email]
> Subject: Re: [EVDL] data logger request
>
>
> Finding dataloggers on line is quite difficult, I've
> found... given that
> they are usually sold to research and development labs or
> departments,
> rather than on-line buyers -- so calling them and talking
> to a development
> engineer there is sometimes all you can do -- and they
> expect you have a
> large budget.  I've done enough datalogging, in labs,
> to know that to use
> the typical equipment they are used to using to monitor 40
> batteries would
> be $2000+ ...  building your own from a simple USB
> enabled datalogger and a
> multiplexer could probably be much cheaper, if you've got
> the skills.
>
> On Mon, Jan 24, 2011 at 11:02 AM, fred <[hidden email]>
> wrote:
>
> > I'll be shifting from lead-acid to lithium iron
> phosphate in the near
> > future.
> > I've had a PakTrakr on the pack since day one and it's
> been rather
> > convenient to
> > know that I'm not damaging my pack as I drive and also
> to know that my
> > charging
> > sequence is working properly.
> >
> > I've done some searching on the wide world of the
> tubes known as the
> > internet
> > and only managed to muddy the waters of my alleged
> mind.
> >
> > Is there an affordable product on the market that will
> connect to 40
> > LiFePO4
> > cells in a pack and monitor and record the voltages
> and current for the
> > pack,
> > cell-for-cell?
> >
> >
> > I realize that it might seem obsessive to want such a
> product/device, but
> > my
> > experience so far has been useful and the additional
> expense seems
> > justified in
> > my opinion.
> >
> >
> > fred ungewitter
> > daytona beach, fl
> > gizmo ev
> > rav4ev
> > sbu v2.0
> >
> >
> >
> >
> > -------------- next part --------------
> > An HTML attachment was scrubbed...
> > URL:
> >
> http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/c3dd767c/attac
> hment.html
> > _______________________________________________
> > | REPLYING: address your message to [hidden email]
> only.
> > | Multiple-address or CCed messages may be rejected.
> > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> > | OTHER HELP: http://evdl.org/help/
> > | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
> >
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> http://lists.sjsu.edu/mailman/private/ev/attachments/20110124/cf14d745/attac
> hment.html
> _______________________________________________
> | REPLYING: address your message to [hidden email]
> only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
>
> --------------------------------------------------------------------
> mail2web - Check your email from the web at
> http://link.mail2web.com/mail2web
>
>
>
> _______________________________________________
> | REPLYING: address your message to [hidden email]
> only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>

_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

Doug Weathers
In reply to this post by fred ungewitter

On Jan 24, 2011, at 11:02 AM, fred wrote:

> Is there an affordable product on the market that will connect to 40 LiFePO4
> cells in a pack and monitor and record the voltages and current for the pack,
> cell-for-cell?

Last year I built a datalogger out of a Parallax Propeller chip and some sensors and a microSD card slot.  It flew into space on a sounding rocket (peak sustained G-load of around 18 gravities), recording data on the microSD card all the way.  I got it back in perfect condition.

Note that I didn't (and still don't) know what I was doing.  I'm just an aging computer hobbyist, not an EE or even a CS grad.

The Propeller is quite easy to program (lots of code already available for download from the Propeller Object Exchange), and it's dead simple to wire up.  We went from concept to sack of parts to delivery in six weeks.

However, if I had it to do over again I'd probably just start with one of these:

<http://gadgetgangster.com/find-a-project/56?projectnum=257>

Already has the microSD slot on it.

Then you could some of these to it:

<http://gadgetgangster.com/find-a-project?subcat=33>

Note the prototyping module with the RCA coax jacks on it.  Looks like it would work nicely for an implementation of Lee Hart's EVILbus.  Hmmm.

The Propeller chip has 32 I/O pins, all of which can be used as either analog or digital input or output, or as a serial port, or I2C or SPI buses, or audio or video, or whatever else you can come up with.  There's no reason you couldn't have several of these all talking to a dashboard unit with a user interface.

The problem of sensing the battery voltages - safely - is left as an exercise for the readers.  What's the minimum amount of easy-to-make hardware required at each cell?  A current-limiting resistor?

--
Doug Weathers
http://www.gdunge.com
"There is no easy way from the Earth to the stars." - Seneca
"We choose to go to the Moon and do the other things - not because  
they are easy, but because they are hard." - John F. Kennedy


_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

martinwinlow
In reply to this post by fred ungewitter
Why don't you continue using the Paktrakr?

Regards, Martin Winlow
Herts, UK
http://www.evalbum.com/2092
www.winlow.co.uk


On 24 Jan 2011, at 18:02, fred wrote:

> I'll be shifting from lead-acid to lithium iron phosphate in the  
> near future.
> I've had a PakTrakr on the pack since day one and it's been rather  
> convenient to
> know that I'm not damaging my pack as I drive and also to know that  
> my charging
> sequence is working properly.
>
> I've done some searching on the wide world of the tubes known as the  
> internet
> and only managed to muddy the waters of my alleged mind.
>
> Is there an affordable product on the market that will connect to 40  
> LiFePO4
> cells in a pack and monitor and record the voltages and current for  
> the pack,
> cell-for-cell?
>
>
> I realize that it might seem obsessive to want such a product/
> device, but my
> experience so far has been useful and the additional expense seems  
> justified in
> my opinion.
>
>
> fred ungewitter

_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

martinwinlow
In reply to this post by damon henry
US$1100 for 40 cells <> 'affordable' in my book!

Regards, Martin Winlow
Herts, UK
http://www.evalbum.com/2092
www.winlow.co.uk

On 24 Jan 2011, at 18:29, damon henry wrote:

>
> It sounds like what I see John Wayland using on the White Zombie at  
> the drag strip might fit the bill for you.  You can get details and  
> pricing on the Manzanita Micro website http://
> www.manzanitamicro.com.  Here is what they have listed as their  
> feature set.
> KEY FEATURES· Real time voltage monitoring of 4 to 8 lithium cells·  
> Real time temperature sensing of up to 8 external temp sensors·  
> Additional temperature sensor included on BMS module’s heat sink·  
> Small size is less than 1 inch thick and 7 inches long by 2.4 inches  
> wide· Quick automatic cell equalization and balancing with high and  
> low voltage on board indicators and outputs to the charger· Two high  
> speed real-time warning lines which can be relay buffered for  
> external use· All BMS modules connect together using readily  
> available RJ cable· BMS easily connects to a PC using the DT USB  
> adapter (Dongle/Terminator sold separately)· Free Windows based  
> scanner and command software available for download  
> atwww.manzanitamicro.com in the download section under MK3 Reg  
> Support.· All commands are easily entered and read in simple ASCII  
> text· Easy user adjustable min and max voltage parameters allow  
> flexibility for various types of lithium cells from 1.75 to 5.5  
> volts per cell· Each BMS board can bypass up to 2.5 amps per cell  
> equating to fast charging and equalization of unbalanced cells· Dual  
> RJ reg bus ports for easy connection to the charger or other BMS  
> units in a simple daisy chain fashion· Self regulating thermal  
> protection and feedback to Manzanita Micro Chargers· Built-in active  
> variable speed 12V DC fan control output on each BMS unit. The fan  
> settings can be viewed and changed using the software found on our  
> website· Large heat spreader is totally isolated from the cells and  
> is already threaded for easy mounting to a larger heat sink.· Each  
> unit can dissipate up to 110 watts
>
>> Date: Mon, 24 Jan 2011 10:02:32 -0800
>> From: [hidden email]
>> To: [hidden email]
>> Subject: [EVDL] data logger request
>> Is there an affordable product on the market that will connect to  
>> 40 LiFePO4
>> cells in a pack and monitor and record the voltages and current for  
>> the pack,
>> cell-for-cell?
>


_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

David Nelson-5
In reply to this post by martinwinlow
I wouldn't use the PakTrakr on LiFePO4 because it does not drain each
cell equally.

On Tuesday, January 25, 2011, Martin WINLOW <[hidden email]> wrote:

> Why don't you continue using the Paktrakr?
>
> Regards, Martin Winlow
> Herts, UK
> http://www.evalbum.com/2092
> www.winlow.co.uk
>
>
> On 24 Jan 2011, at 18:02, fred wrote:
>
>> I'll be shifting from lead-acid to lithium iron phosphate in the
>> near future.
>> I've had a PakTrakr on the pack since day one and it's been rather
>> convenient to
>> know that I'm not damaging my pack as I drive and also to know that
>> my charging
>> sequence is working properly.
>>
>> I've done some searching on the wide world of the tubes known as the
>> internet
>> and only managed to muddy the waters of my alleged mind.
>>
>> Is there an affordable product on the market that will connect to 40
>> LiFePO4
>> cells in a pack and monitor and record the voltages and current for
>> the pack,
>> cell-for-cell?
>>
>>
>> I realize that it might seem obsessive to want such a product/
>> device, but my
>> experience so far has been useful and the additional expense seems
>> justified in
>> my opinion.
>>
>>
>> fred ungewitter
>
> _______________________________________________
> | REPLYING: address your message to [hidden email] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>

--
David D. Nelson
http://evalbum.com/1328

_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Low cost display

rodhower
This may be handy for an indash display,
http://www2.electronicproducts.com/Inexpensive_meter_software_bring_panel_meters_into_the_21st_century-article-poyrc02_jan2011-html.aspx

_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

dave cover-2
In reply to this post by martinwinlow
> On Tue Martin wrote:
> US$1100 for 40 cells <> 'affordable' in my book!

Martin

That depends on how long you need/expect your pack to last and how
much it will cost to replace it.

Dave Cover



--
http://www.evalbum.com/2149

_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
Reply | Threaded
Open this post in threaded view
|

Re: data logger request

fred ungewitter
In reply to this post by fred ungewitter
Corbin, Since I don't want a BMS, the price is excessive, in my opinion. If I
wanted a BMS, then I would consider the price to be appropriate.

Damon, see above. My price point is based on product versus perceived value.
I'll pay through the nose to get exactly what I want, but I really don't want to
pay for something that won't be used, as in a BMS.

Damon and Matt, I've been in touch with Ken from PakTrakr and he's told me that
the LiFePO4 version will handle up to 40 cells, although I need only to read 20,
but the worst of it is that it pulls from three cells out of eight. That's a
recipe for unbalance, in my opinion. My experience with the PakTrakr is that the
resolution or the accuracy is lacking, although Ken did say he's added an extra
digit to the right of the decimal point. That's no good if there's no accuracy
(reported often in other forums) and no good if the pack goes unbalanced on a
regular basis. Other LiFePO4 pack users have reported very little trouble in
keeping a balanced pack, and don't have mid-pack loading.

Doug, I'm probably going to destroy what little grey matter I have remaining,
but your solution appears to be just what I want.  I don't have the skills to
modify computer mice to squeak voltage readings at me, although I find the
concept intriguing and the execution impressive. It's that sort of thing that I
very much enjoy to read about. Success with items at hand is far better than
collecting esoteric materials and devices, although it appears that the Gangster
stuff falls about in the middle. It's really what I was hoping to find and I've
also discovered the forums for that platform.

I noted the video and audio module for the Gangster. I don't think that fits
into my limited programming skills, but it makes me consider that Norm's display
might be fed from a Gangster. I realize that the product is called the Gadget
Gangster. I like the name!

What's an EVILbus? Is there a link available?

I'm hopeful that there are people in that forum as good as the people in this
one!


------------------------------


From: corbin dunn <[hidden email]>

Hi Fred,
The Elithion Lithiumate BMS will do this. I'm using it for my new EV, and I like
it a lot. Affordable is relative...it is probably $1000-$1200. Depending on the
cost of the batteries that is quite affordable.
------------------------------
From: "[hidden email]" <[hidden email]>

Well, I've been working on something for the past few months, but I haven't
said anything about it here on the EVDL because it might seem a silly way
to go.  I've actually got a prototype system running on my workbench right
now that uses USB computer mice to send cell voltage info to a laptop.
Each mouse monitors the voltage of 4 cells, using the three mouse buttons
and the scroll wheel.  

Basically, I removed the microswitches on each mouse button/wheel and
replaced them with optos.  A PIC chip at each cell measures the voltage
every few seconds, then closes/opens the opto to simulate mouse clicks.  A
Java program running on the PC displays reads to mouse clicks on the USB
ports to display real-time info and record the history.

My goal was that components would cost less than $1.00US per cell.  Each
mouse cost 99 cents and measures four cells, so it was like buying a
pre-made circuit for 25 cents per cell.  I'm trying to find a way to
increase it to 6 cells per mouse, using some of the chip's other
functionality, which would make it even cheaper per cell.  Peripheral stuff
(capacitors, optos, resistors) adds up to about 60 cents per cell.  

Hey, I told you it was silly.

------------------------------
From: damon henry <[hidden email]>

Ok, wasn't sure what your price point was.  Seems like you could use your
paktraker that you are already familiar with.  It would not give you individual
cell data, but you could wire one sensor across multiple cells and still get
some pretty useful data.
------------------------------
From: "matt lacey" <[hidden email]>

If you are going to use the paktrakr with lithium cells,
make sure the first "12v" lead isn't connected to the actual pack.

The power for the module comes from the first battery, pulling it outta
balance relative to the rest of the pack.

------------------------------
From: Doug Weathers <[hidden email]>

Last year I built a datalogger out of a Parallax Propeller chip and some sensors
and a microSD card slot.  It flew into space on a sounding rocket (peak
sustained G-load of around 18 gravities), recording data on the microSD card all
the way.  I got it back in perfect condition.

Note that I didn't (and still don't) know what I was doing.  I'm just an aging
computer hobbyist, not an EE or even a CS grad.

The Propeller is quite easy to program (lots of code already available for
download from the Propeller Object Exchange), and it's dead simple to wire up.  
We went from concept to sack of parts to delivery in six weeks.

However, if I had it to do over again I'd probably just start with one of these:

<http://gadgetgangster.com/find-a-project/56?projectnum=257>

Already has the microSD slot on it.

Then you could some of these to it:

<http://gadgetgangster.com/find-a-project?subcat=33>

Note the prototyping module with the RCA coax jacks on it.  Looks like it would
work nicely for an implementation of Lee Hart's EVILbus.  Hmmm.

The Propeller chip has 32 I/O pins, all of which can be used as either analog or
digital input or output, or as a serial port, or I2C or SPI buses, or audio or
video, or whatever else you can come up with.  There's no reason you couldn't
have several of these all talking to a dashboard unit with a user interface.

The problem of sensing the battery voltages - safely - is left as an exercise
for the readers.  What's the minimum amount of easy-to-make hardware required at
each cell?  A current-limiting resistor?

end of compiled messages
**********************************



     
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110125/0f0d87ed/attachment.html 
_______________________________________________
| REPLYING: address your message to [hidden email] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
12