[ausev] Battery choices

[Mike Seningen]

Sorry if this is a bit simplistic -- but I'm confusing myself here:

Help with apples to apples here:

Trying to determine an equivalent number of needed Li Ion cells relative 
to one AGM Deep Cycle.

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)

If so -- In bulk I have seen these Li-ion at about $2 per cell.  that 
puts it at 100AH @ 144V for $4600.

you of course would need to pack it and put some battery control 
circuitry in there.
(the thought of building a pack for 2300 cells seems quite tedious!)

Also weighs in <350lb (cells only) --- compared to 840lb+ for Pb.

While $4600 is nothing to sneeze at -- the AGM batteries are $150-200 or 
so, even at $150 per,
thats $1800.

If my numbers are right -- that puts the Li-on closer to 3:1????

I'm sure I'm missing something.......

thanks,

Mike




Rob H wrote:
> As a rule, it seems that for equal capacity, pb is 10x the weight for 
> 1/10 the cost of Li.  Li options do not supply as much current so the 
> max power out (P=IE) is limited.
>
> For Pb conversions, you should estimate 1/3 of the GVW as lead.  Too 
> much will cut your range, too little will (of course) cut your range.
>
> 50 miles at highway speed will take some effort.
>
> On Sun, Jul 6, 2008 at 11:44 AM, Mike Seningen 
> <mseningen at austin.rr.com <mailto:mseningen at austin.rr.com>> wrote:
>
>
>     I'm reading -- Pb are cheaper -- but heavier
>     Li Ion are getting cheaper -- but not there yet.
>
>     One of the problems with reading internet articles -- is that
>     there are
>     rarely time stamped -- so
>     you really don't get a feel for what "not there yet" really means.
>
>     Can someone point me to prices for Pb, and Li Ion batteries/packs to
>     continue my homework.
>     I'm trying to get values to plug into a spreadsheet and see what
>     my $$$,
>     and weight deltas would be.
>
>     Assume I'm looking to do 50 miles, at highway speeds in the Hill
>     Country
>     on a single charge,
>     make up of 2 or 3 equal distant runs.
>
>     merci!
>
>     Mike
>
>
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>
>
>
> -- 
> Rob
> ____________
> Rob Hirschfeld
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