I suggest you have a look for LiFePo batteries, some one had a link for them
here
a few months ago. the size and performance is quite a bit better than LiPo.
If memory
serves a 14v battery weighed in at about a pound and was good for about
150amp draw
so you could use it to start your A/C a bit of quick hunting I found AA size
cells 3.2 volts
at 10Ah capacity.

http://www.alibaba.com/product-gs/225162127/Lithium_Battery_Pack_12V_20Ah_Li
FePO4.html
  -----Original Message-----
  From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Paul McAllister
  Sent: Tuesday, 7 April 2009 8:49 AM
  To: europa-list@matronics.com
  Subject: Re: Europa-List: Battery capacity


  Hi All,

  I am trying to determine the battery technology.  Unless I am missing it,
I can't find it stated.  Can anyone else ?

  I did find a light weight battery for the race car fraternity that was Li
Ion, that was 4 pounds at around  16 a/h capacity, but I have lost the URL.

  The Li Ion tehnology brings with it different problems.  I saw a very
impressive video demonstrating a nail piercing a set of cells, the result
was explosive to say the least.

  Anyhow, if anyone tumbles over the URL please forward it on to me.

  Cheers,  Paul