[ausev] meeting

[Willie McKemie]

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