[Oeva-list] Re: used batteries

Bryan Avery bryan at photonlight.com
Sat Jun 11 16:19:23 PDT 2005


Yes, I think the 336V of 28Ah batteries sounds like the way to go.  Given
the same 681 pounds in a lower voltage higher Ah pack, the range should be
about the same I think, but as you suggested it might actually be more
expensive this way given that the ~40Ah batteries seem to be a bit more
expensive and there would be no opportunity for combining our orders for the
volume discount.  As for performance, it seems that peak power from the
siemens system is essentially current limited up to about the 336V range so
all else being equal, the higher voltage pack would get me the best
performance possible from the drive system.

 

I'm definitely interested in getting together for the volume pricing.  With
your 52 plus my 28, that gives us a total of 80 batteries for the order.  If
Gary wants another 20-28 for the Insight, that would put us up to 100
easily.  What did they quote you for shipping?  It seems that shipping
through a regular freight trucking company shouldn't be too bad with such a
large order.  Since the bulk of the order is going to be yours, we should
probably just have everything shipped to you and then I can drive up and
haul my bunch back down to Eugene myself. 

 

That's good to know about the powercheqs.  I've already got a bunch of
circuit boards printed & all the components for a set of the
voltage-regulator circuits that Victor designed for the TS cells.  I think
it may just be a matter of changing the resistor values to use the same
circuit with the lead acid batteries.  That would probably be the cheapest
solution since I've already got most of the components, although I'm not
quite sure about how well they would interface with the PFC charger (or if
that's even necessary).  The Rudman regulators I suppose would be the most
plug-and-play solution and guaranteed to do what I need.

 

-Bryan

 

-----Original Message-----
From: Theoldcars at aol.com [mailto:Theoldcars at aol.com] 
Sent: Friday, June 10, 2005 11:05 PM
To: bryan at photonlight.com
Subject: Re: [Oeva-list] Re: used batteries

 

Hello Bryan

 

With 336 volts the batteries would weigh 681 pounds. The batteries would
cost you more than used batteries if you could find what you need. New
though would provide years of reliable service until you find a better
replacement. 

 

The voltage you need and the weight I think makes these your best option.
With this even when your batteries were at 10.5 volts the pack would still
have 294 volts. The other thing I have noticed is the 33 to 42 Ah batteries
cost a lot more. Some as much as double this 28 Ah price. The 28 Ah battery
must fit more applications which allow the price drop. 

 

If you went on the low end 240 volt pack with 20 batteries they could only
weigh 32.5 pounds. Not enough to get into the larger better priced
batteries. With the higher voltage pack you would pull less Amps? With a
larger Ah battery and less pack voltage you would be placing a higher load
on them this would be a reduction in range correct? Would there really be
any gain then?

 

Digi-Key 1-800-344-4539 and Fedco 1-800-542-9761 both carry the 28 Ah. I
found they will try and beat one another on pricing. I would have liked a
little larger Ah battery but anything bigger than the 28 Ah will not fit in
the existing space. I have to do a buddy pack and this is the best deal I
have found on this size battery. I started with Digi-Key with a 52 battery
order and they were willing to sell them for 43.29 which is the 120 price
break they show. I contacted Fedco and they went to 41.45 for a 52 order.
They would do 100 for 39.95 so I went with them. I would be willing to order
another 52 to add to yours if it gets you the better prices. The only other
thing to watch for is shipping. Digi-Key at first was trying to charge 1500
dollars I had them contact their shipping department and the price was way
off.

 

Gary was telling me the power cheqs are not good for leveling during a
charge and I think he said some burned up. He said the Rudman regulators
would be the best way to go. 

 

I can assure you know more about electric vehicles than I do. I just happen
to have a hundred hours searching for AGM batteries and their prices in the
30Ah to 65Ah range.

 

Let me know if you would like to take advantage of the high quantity pricing
together. Gary might also be interested.

 

Don Blazer

 

 

 

In a message dated 6/10/2005 2:23:49 PM Pacific Daylight Time,
bryan at photonlight.com writes:

I've got one of Victor's AC systems, so 240V-336V is the recommended voltage
range with the higher voltage giving the best performance.  336V of the
Panasonic 28Ah batteries would be just about right at ~650lbs.  Of course,
240V of larger capacity batteries would probably be a little bit cheaper
though.  With a smaller pack like this, I imagine battery balancing is going
to be even more critical than it might otherwise be, necessitating the use
of Rudman regulators / powercheqs / or some other similar device?  Don,
where have you found the $45 price?  The best price I found with my brief
internet searches was $50 ea. + s/h in quantity from digikey, but every
other site I found had them listed at around $90.  At $45, that would be
$1260 + shipping which is a bit more than I was hoping to pay for a "cheap
temporary" pack, but at this point it's almost worth that just to get the
car on the road finally.  And of course, at the rate things have been going
with the TS cell replacement this could end up being a bit more than
temporary, in which case I will probably be happier spending the money on
the brand new batteries & high voltage pack than just going with used
batteries that are already near the end of their useful life.

 

Any other thoughts, advice, or things I should consider?

 

-Bryan

 

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