Dc for power supply

An interesting question. I personally don't think that there would be any sonic difference in batteries, especially when using them for just the filaments. However stranger things are known to occur in this hobby. The use of batteries keep popping up in conversation to power audio gear. I.E. Southerland, Vinnie Rossi and Stromtank to name a few. 
I myself keep toying with the idea of installing a solar array to maintain the charge on a set of car batteries (installed outside).. Then using a pure sign wave inverter to produce 110VAC to power my system.
Got the idea from  my APC S15BLK power conditioner. It has battery back up with pure sign wave regeneration. Upon any main power disruption the battery backup kicks in. Even with the smaller batteries in the APC it can run my system for a very reasonable time. 1-2 hours.

 dc filament on a cd player

- eh?

you can certainly run a car stereo off a storage battery - what components are you planning to use?  (not a Class A tube amp, I hope)

any commonly available battery chemistry should be fine

Waste of time. Totally inadequate power. 

noise - free power

I think the OP is a non-native English speaker and filament means something else

if so, go ahead and put a post in your native language below your response - somebody may be bi-lingual

I tried using 2 x 12v lead acid 6Ah batteries in an ECC88 tube head amp (MC phono amp). It was quiet but sounded significantly worse with loss of air and dynamics. Reconnecting internal 24Vdc regulated solid state supply brought it back to life (but with a trace of mains ripple noise).

Noromance: try using a higher ah.  Your ah is too low, you need at least 12v 68-150ah ( car battery). No need to worry about ah if you have a regulator that can do dc-dc drop.   

@zipost Good point. Long time ago though. I did only use it for B+. Left heaters on AC psu. If I ever do DC, I'll use a car battery!

Another point i also notice.   Not all 12dc car battey are the same, i strongly recommend Odyssey battery at least 80-175ah.   Even the new technology Lithium or even the lithium polymer, the sounds has no dynamics.  In audio, i strongly prefer just lead acid or Agm ( glass mat).  

Zipost - You started this thread in 2017. Have you learned anything more about different battery types and audio quality?