Perfect scope battery ??

I have too many scopes and want to pare down the collection to three or four scopes that will do pretty much everything a visual observer could want. While I know this is a broad-ended question, what would you see as the best all around battery of scopes if given a three or four scope limit?

Thanks!

A 12 volt Gel-Cell apprx. 8 ampere/hours with a constant voltage charger of 12.85 V. apprx. You can use a voltage regulator from radio shack to adjust the 12 volts down to 9 or 6 VDC too. Gel-Cells frequently show up at swap meets and are always found at radio amateur swaps in your area. Hope this helps. -Larry