[ausev] meeting

[Paul Widmer]

I think you hit 2 of the 3 points when I was talking to you, no worries.
Thanks for the info Willie!

-Paul


On Sat, Mar 14, 2009 at 6:09 PM, Willie McKemie <mckemie at spamcop.net> wrote:

> I enjoyed my second AustinEV meeting today.
>
> I was chatting with someone about the advantages of using large LFP
> cells and did not come up with the points I wished to make.
> Befuddlement, be gone.  Here are the points:
> 1) large (>=200ah) TS LFP cells have an advertised life of 3000 cycles
> at 80% discharge and 4000 cycles at 70%.  Smaller cells are 2000 and
> 3000 cycles.
> 2) For a given application, the large cells can be discharged and
> charged at lower relative rates.  I infrequently demand more than .5C
> and never more than 2C.  The low rates are supposed to lead to
> longevity.
> 3) For a given voltage and given average trip length, the large cells
> will be discharged to a higher SOC than smaller cells.  That, also,
> leads to longevity.
> So, that is the "triple whammy" that makes large cells more attractive
> with respect to longevity.
>
> I am frequently asked about the cost of TS cells.  I always get to talk
> about:
> 1) I paid $1.50/ah (about $400/cell and about $18K for my 45 cell
> pack).
> 2) They might be bought now for $1.30/ah.
> However, I don't always get around to mentioning the other expenses:
> 1) Shipping.  As I recall, about $1.3K from China to Houston by ship.
> 2) Shipping insurance - 1%
> 3) Import broker fees.  These were modest, about $300, as I recall.
> 4) Import duty.  3%, again, as I recall.
> 5) Shipping from Houston to Kansas was supposed to be about $700, but
> ended up more like $200.
> All the above were applied to 77 TS-LFP260 cells.  Only 45 of those
> cells are in the Hyundai.
> I paid EV-Power of Australia $3.5K Australian dollars for
> 2 TBS meters, 2 EV-Power control units, and 77 EV-Power cell modules.
> I believe a AuD is worth about $.75 USD.  The cost of the BMS and TBS
> meter for a 45 cell pack would then be about $1400 US.
>
> http://www.evalbum.com/2314
>
> --
> Willie, ONWARD!  Through the fog!
> http://counter.li.org Linux registered user #228836 since 1995
> Debian3.1/GNU/Linux system uptime  455 days 12 hours 26 minutes
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>
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