external power supply for Canon EOS400D or 50D

Hi all,
is any product available I can use with Canon EOS 400D or 50D body to plugin an external Powersupply, such as:
http://www.solariflex.com/20-batterie-externe-universelle-50w-mp3450.html
(withou using grip extensions holding 2 Canon accus or 6 AA cells...)
I found this product above in merlin/pw thread as source for the Merlin pano head.
background: standard canon 750ma accu is accurate if using 18-55mm lens. but If I use sigma 120-400 APG DS OS lens I can take 60 raw images (if OS is activated... ok in practice for panos senseless...).
So if I plan to use a bigger pano using HDR I finally can take max. 60/3 = 20 images before changing battery ;-).
in case of 360 pano I have to change battery 5-6 times per row ;-)
something like a mobile diesel would be perfect ;-))
Liebe Gruesse,
Georg
is any product available I can use with Canon EOS 400D or 50D body to plugin an external Powersupply, such as:
http://www.solariflex.com/20-batterie-externe-universelle-50w-mp3450.html
(withou using grip extensions holding 2 Canon accus or 6 AA cells...)
I found this product above in merlin/pw thread as source for the Merlin pano head.
background: standard canon 750ma accu is accurate if using 18-55mm lens. but If I use sigma 120-400 APG DS OS lens I can take 60 raw images (if OS is activated... ok in practice for panos senseless...).
So if I plan to use a bigger pano using HDR I finally can take max. 60/3 = 20 images before changing battery ;-).
in case of 360 pano I have to change battery 5-6 times per row ;-)
something like a mobile diesel would be perfect ;-))
Liebe Gruesse,
Georg