[ausev] Battery choices

[Mike Seningen]

I will look into the charger as well as the battery pak electronics too.

I just want to make sure my numbers are correct -- and that I am not 
deluding
myself into thinking it maybe more economical than is reality.

thanks

mike


Rob H wrote:
> This is great!  It's nice to have a better info than the rule of thumb 
> that I'd been working on.
>
> Please be sure we factor in the costs of the charging system.
>
> On Mon, Jul 7, 2008 at 7:42 AM, Mike Seningen <mseningen at austin.rr.com 
> <mailto:mseningen at austin.rr.com>> wrote:
>
>     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> <mailto: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.)
>>
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>
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> Rob
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