Hi
One of the guys in my local club uses one of these batteries to power his 22" Obsession clone with full goto / argo navis and heaters/cooling fans. Its a 36 Amp hour deep cycle battery (like a marine battery). It is surprisingly small-slightly smaller than a standard power pack but obviously heavier. He claims to get 3 nights out of a full charge. They are normally used to power portable fridges in camper vans/ boats and are available from Waeco. Not sure if it is available in Europe but it probably is. This is my next purchase as soon as the Halford power packs die (mind you they are still going strong after 4 years-recharged immediately after each use). Just over $300 Australian.
www.raysoutdoors.com.au/online-store/pro...d=310026#Description
www.waeco.com.au/products4.asp?id=259&ca...tId=78&subCatId2=127
  