There is no electronical reason not to use them, as they will provide the DAC and receiver with perfect DC
and very low internal resistance.

However, the "sealed" part of SLA is not exactly sealed, so I really don't want an SLA-battery inside the house.
I could elaborate on this topic (we use 100's of them @ work), but I guess you'll share my opinion when reading the wiki:
http://en.wikipedia.org/wiki/Lead-acid_battery

If you really want to use batteries, you'd better examine these: http://www.nrgdynamics.co.uk/index.htm
Those NiMh IB4200 cells can deliver 35Amps at an internal resistance of less than 2Ohms.
The guy at nrgdynamics can configure those cells in a pack, so actually you can choose any voltage you want.
The only downsize is that you have to charge them with a NiMh-compatible charger.

I know, not exactly something you see in high end, but far more safe than keeping an SLA battery inside the house.

--> up till now, I only used these batteries to power the brushless engines of my buggies, but I like your idea,
battery-powering digital audio ;)

Edited by user Monday, September 10, 2007 2:23:26 PM(UTC)  | Reason: Not specified