I was just pricing the cost of buying a sealed gel battery (50-100Ah) compared to a small generator. You can pick up a Homelite 720W 2 stroke generator from Bunnings for $150. Even a relatively cheap 50Ah gel battery will set you back over $200-$250!!!!!
You could buy a small generator, a small UPS and some extension cords for about the same cost as you'd pay for one of the smaller batteries and the what makes it even better is you'll have power for a lot longer. Buy some power supplies for your equipment or use the ones they come with and you're set!!!
No need to buy multiple batteries to run everything.
This would be great if you're running several scopes at the same time, away from home, plus all the add on bits.