On the back cover of the April issue of Motorcycle Consumer News is a review of an 18 Ah Shorai LFX motorcycle battery ($186.95 MSRP) in a Honda Goldwing and a Kawasaki Concours. The reviewer was happy with the performance and light weight of this battery when used in these two motorcycles.
However, what caught my eye, is mention that Shorai promises a battery range in 24, 27 and 36 Ah battery sizes, to be offered in April 2011. Since these are pretty large for a motorcycle, I assume that they will be aimed at car usage. In any case, it seems to me that this size battery might be of use to anyone who has an electric motorcycle that is currently using auto lead-acid batteries. I imagine that if you connected several of the 12 V 36 Ah batteries in series, that would make a pretty simple conversion to a light-weight, much smaller, and hopefully longer-lasting battery system.
To give you an example how light these batteries are compared with AGM types, the stock AGM battery for the Gold Wing weighs over 15 pounds, while the equivalent replacement Shorai battery weighs under 2 pounds and is much smaller, according to the article. That sounds like a great advance for an off-the-shelf 12 V battery and one that perhaps might be something worth investigating as a power source when these larger batteries become available