[Oeva-list] Last Call Lee Hart Battery balancer mail thread

Theoldcars at aol.com Theoldcars at aol.com
Thu Apr 19 00:04:56 PDT 2007

We have gone one month and it  is time to now to place the order. I have sent 
this on to any groups  that I thought would be interested. 
Anyone wanting to review here is the link and past  emails are below.

Lee has asked for an email describing what you want below in Green.  

I have sent this to everyone who has responded. In case I missed anyone  I  
included the EV list. I am also going to send this on to some other  list 
this balancer would really help with.

1. Question  below by Paul can we add temperature probes?

2. In a prior email in red  below Lee brought up saving manufacturing  cost.  

The above  one and two going different directions. I would be for spending  
the  extra money for more options. I have little doubt in a short time we 
will be  
working with lithium batteries. Heat is a critical factor with them as well  
as  other battery technologies. The savings I am for is producing more  so 
cost is reduced. 

Please respond to all to keep everyone  informed.

Thank you

In a message dated 3/14/2007  1:11:15 PM Pacific Daylight Time,  
paul.wallace at intel.com  writes:


The design as it stands doesn't have enough  temperature  probe ports for 
NiMh.  I think that we need one probe  per  battery.  It is probably 
possible to add a multiplexer for  multiple  temperature probes and let 
the stamp select them at the same  time it is  selecting the battery it is 
going to measure voltage   on.


> Specifically, the old control board used  an  external digital multimeter 
> with isolated RS-232 output to  measure  battery voltage and current. They 
> cost $50-$100. I'm  experimenting with  a cheaper on-board circuit to do 
> this (since  everyone is obsessed with  cost).

Yes, there's an order in  the works. I'm trying to work  out the final 
details, and figure out  how many to order, and what features  people 
want/need. Stay  tuned!

What would help is if interested  parties send me an email  describing 
what they want;

1. Bare boards  only (with schematics  and parts lists)

2. Parts kits (boards with parts,  which you  assemble yourself)

3. Assembled boards (which you just need to  be  put into a box)

On the software side, I don't have the  time/resources  to supply more 
than a demo program (what I'm using for  my own EV). You will  need to 
change the program to suit your battery  pack (number of batteries,  
voltage per battery), the balancing method  you want to use (if different  
from mine), and other auxiliary  functions (like temperature measurement,  
charger control, fan control,  heater control, etc.) So, I would suggest  
that you buy your own BASIC  Stamp with its development kit, so you can  
make these  changes.

Time: This is a side project for me. I have a  backlog of  other contracts 
ahead of this one that I need to finish first, so   delivery is probably 
going to be 2-3 months.

Note: Just saying  you  want one won't make it so. Serious orders only! 
It's too expensive  a project  for me to order all the parts on the CHANCE 
that you MIGHT  buy it. Once I  know how many we need, then I can quote a 
price. When  folks pay for it, I  place the orders.

Ring the bells that  still can ring
Forget the  perfect offering
There is a crack in  everything
That's how the light gets  in    --     Leonard Cohen
Lee A. Hart, 814 8th Ave  N, Sartell MN 56377,   leeahart_at_earthlink.net

************************************** See what's free at http://www.aol.com.
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