I ended up buying this (link below) you can make offer which I made at $175 and they accepted.
Extreme Mini Mate Thumper 15 AH 12 Volt Battery Pack - Cigarette & USB outlet
http://cgi.ebay.com.au/ws/eBayISAPI....m=291105825242
SPECS
Thumper Extreme Mini Mate 15 AH Battery Pack
Introducing the Extreme Thumper Mini!
This limited edition unit is the smallest of the Thumper range.
Offering 15 AH of battery storage, 1 x cigarette type outlet, DUAL USB outlets, digital volt meter for accurate reading and a two pin socket for charging, this unit is designed for a person with a small power draw.
Ideal for running lighting and small draw 12 Volt accessories, the Thumper Mini will even have the capability of running a 40Lt compressor type fridge for an approx time of 6 – 8 hours (variables apply).
The Thumper comes included with a 2 Pin to cigarette plug charge lead.
If completely discharged (10.5Volts) the unit will reach fully charged off the vehicle's factory fitted cigarette outlet within 3 hours of drive time!
The Thumper Mini is a perfect companion to link with a larger Thumper in order to increase your capacity. It may also be linked to a larger Thumper in order to recharge together from the same charging source.
Please contact our store for options to charge you Thumper Mini via 240 Volt.
Weight – 5 kg Length – 165mm
Height – 175mm Width – 140mm
2 Year Warranty
R.R.P $ 229.00