[MagnusH]

I have a DAC that takes 10 - 15V input, and would like to run it on batteries, something like 12V and 20Ah, but which battery type is best? SLA, LiFePo4, Gel, AGM etc? Other technologies?

Obviously there should not be any interfering electronics in the battery, which might make some LiFePo4 less suited!

From what I understand a low internal resistance in combination with electronically quiet is best.

Suggestions?

 

[wink]

Any battery at the correct voltave should do as long as it has the capacity to run the equipment for the length of time it needs to be used.
Recharging the battery when the battery is connected to the equipment and running it will introduce power supply noise to some degree.

 

[MagnusH]

Charging while using is not a good idea, than the charger becomes the power source which is anything but optimal for HiFi. So I plan to take a big battery that lasts more than a day, and then charge each night when sleeping.

But the question is, which type of battery will make the DAC sound best?

 

[sonance]

Batteries still have residual DC noise and ripple - a high quality filtered linear power supply should sound better. But compared to a crappy switched wallwart (some switching supplies are better than others) a battery would be better.
https://medium.com/@larryhotwit/battery-power-vs-linear-power-supply-915cbf1854b0
https://www.mojo-audio.com/power-supply-faqs/

To get back to your question, many generic battery packs have dc to dv switching circuitry to maintain voltage and will not be optimized for audio. Some companies that build raspberry pi streamers and DACs sell isolators + battery packs that would work better if you are taking a DIY apporach (e.g. https://www.allo.com/sparky/isolator.html and https://www.allo.com/sparky/battery-pack.html). I'm sure there are decent all in one solutions out there that are audio optimized. Just don't assume a generic battery is going to sound "good".

 

[MagnusH]

The reason I like batteries (especially in combination with toslink) is that you get away from the mains grid. No more "my HiFi sounds better at night". And a little varying voltage over time is no problem, as long as the DAC has good internal voltage regulators (which most do).

I bought a sealed lead acid battery today, it has 12V, 17Ah and 6 mohm internal resistance which means it can very fast (much faster than any voltage regulator) supply the power needed. I have also heard that SLA batteries are used as reference by many manufacturers of LPS.

Power banks are not good though as you say, they contain very cheap switched regulators.

And yes, the sound improved