[SPARCbook] Ultrabook AC adapter replacement

[Super-User]

Hello all!

I'm in need of an ac-adapter for the Ultrabook I 200 MHz.

It can be ordered from Tadpole but the price is trough the roof as usual
with them.
Do anyone know if there is any special quirks to this battery charger /
AC - adapter.
Would it be possible to replace it with something less expensive.

The connector is rather unusual but the pinout is in the manual so it
should be possible
to connect some other power supply if I can find one of these unusual
connectors.
(its small and circular with 5 pins in it, it appears to be different
from the Ultrabook II which uses a more
standard plug)

The voltage is 18V according to the manual. I guess one should take out
the battery if using
another power supply, but what would the odds be of damaging the actual
laptop, provided 
the voltage is <=18V ?

BTW, if anyone has an ac-adapter to sell I would of course be
interested.

Thanks
Peter