Aldi Power Station

Anyone know how many amp hours this delivers?

You can get 12v - 9v DC-DC convertors which will then happily power the ETX. Like this one;

www.powerstream.com/dc6.htm

Just make sure you get the polarity right!!

You could even knock one up yourself if your brave.

www.uoguelph.ca/~antoon/circ/car912.htm