[ausev] Battery choices

[Mike Seningen]

Thank you Brian --

if what you say is correct that one would need 1/2 the battery energy of 
the AGMs
(and I have no reason to doubt you), at ~$2 cell, that make these 
LiFePO4 very competitive.

That puts it at  1.5x-2x the cost, with 1/5-1/6 the weight.

Granted this is a manufacturer direct, Chineese supplier -- but still 
very interesting.....

http://www.fuzing.com/vli/0005509cd235/Li_ion-battery

The same type of cell was tested here:

http://zeva.com.au/tech/headway/

will continue to do some more homework,

Mike


Brian Lasseter wrote:
> On Mon, Jul 7, 2008 at 12:23 AM, Mike Seningen <mseningen at austin.rr.com> wrote:
>   
>> 12v 20 Hr Rate AH = 100  -- so is this a 100AH battery at 12v -- or 1200AH at 12v?
>>
>> Li-ion 3.7v @1.7AH -- to get 100AH @ 12v is roughly 190cells?  (100/1.7)*(12/3.7)
>>     
>
> Volts X Amp_Hours = Watt_Hours
>
> 12V x 100AH = 1200wh of energy for your AGM.
> 3.7V x 1.7AH = 6.29wh of energy for your Li-ion cell.
>
> Your final count of 190 li-ion cells would give you the same energy though.
>
> However, just to confuse you more, the peukert exponent comes into
> play here.  Long story short... the li-ion cell can use nearly 100% of
> it's energy, while the AGM cell will likely only be able to use 50% of
> it's energy at the high rate of energy depletion used in electric cars
> (depending on what it's peukert exponent is).
>
> So... 95 li-ion cells should suffice to give you the same amount of
> "useable" energy.  If you know the peukert exponents for each battery,
> then you could calculate an exact number.
>
> http://en.wikipedia.org/wiki/Peukert%27s_law
> http://www.smartgauge.co.uk/peukert_depth.html
>
> --
> TTFN,
> Brian "Lasso" Lasseter
>
> · (512)736-1677 · AIM:digininja · ICQ:2238123 · MSN:azoreg ·
> "No Sane man will dance." -Cicero (106-43 B.C.)
>
> _______________________________________________
> AusEV mailing list
> AusEV at austinev.org
> http://www.austinev.org/mailman/listinfo/ausev
>
>   
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.austinev.org/pipermail/ausev/attachments/20080707/580360d3/attachment.html