Why do we not see more battery powered audio gear?

[PHC1]

I'm a bit surprised that with all the attention we pay to "clean up" our AC to get clean power for a more faithful sound reproduction that the audio industry has not adopted some more DC powered designs. Since the invention of Lithium Polymer batteries and those batteries pack some serious punch, I think it would be feasible. I have not done any calculations but was thinking about it the other day so maybe I will try to approximate how that would work out.

We obviously see tons of smaller/portable devices that are running on rechargeable batteries but nothing in terms of bigger amps we use for home audio.

But with the larger LiPo packs, even the hobby grade ones I use for my helicopters, I am running 12s packs (44.4V) that can easily put out 200 amps according to my transmitter telemetry while flying my models hard! That's 8800 watts of power on peak bursts of high g-load maneuvers and the batteries can take it! Obviously at that rate the charge only lasts a few minutes but our amplifiers are not drawing anywhere near that amount since we are limited to 15 to 20 amperes from our home wiring and most of the time are just cruising our amps at fractions of the actual peak power.

Would eliminate the need for fancy power conditioners and deliver clean and robust power. The only drawback being is that they need to be recharged but that can easily be incorporated into the design.

Something to think about.

Anyone aware of any battery powered audio amplifiers? I've seen phonostages and preamplifiers but no amplifiers I can think of.

[jdandy]

Serge.......The Aurender W20 music server is battery powered.

https://aurender.com/w20

[PHC1]

Originally Posted by jdandy

Serge.......The Aurender W20 music server is battery powered.

https://aurender.com/w20

Dan, interesting, they chose their flagship server to receive the battery treatment for the dramatically lower noise floor. I'm not familiar with Aurender pricing. What does that server retail for?

[jzzmusician]

Serge,

Found it online for $17,500.00

[PHC1]

Originally Posted by jzzmusician

Serge,

Found it online for $17,500.00

Thanks Bob. Not exactly a cheap product but it is their flagship. In any case, it may or may not be an interesting idea but I will certainly put this on my "to think about" list.

[SteveJ]

From a power quality point of view it is a no brainer.

From a marketing point of view there are issues. The configuration of a commercially viable unit must appeal to everyone that would purchase said unit. The prospect of changing batteries would deter some that would otherwise purchase a particular unit although to your point, might entice others.

The prospect of encountering a degradation of sound quality due to low batteries might be another deterrent.

If it were configured such that it would be charged when the unit is turned off and completely disengage the charging circuitry when the unit was turned on, an internal, rechargeable battery pack might overcome these concerns.

[W9TR]

My digital audio player (MSFT Surface Pro) and DAC are battery powered. I can’t hear a difference when they are connected to mains power though.

Sutherland makes some battery powered phono preamps that are highly regarded.

With rechargeable batteries so powerful and inexpensive, I’m also wondering why more designers don’t go this route.

Tom

[jdandy]

Aurender W20 music server review from The Absolute Sound.

https://www.theabsolutesound.com/art...usic-server-1/

[PHC1]

Originally Posted by SteveJ

From a power quality point of view it is a no brainer.

From a marketing point of view there are issues. The configuration of a commercially viable unit must appeal to everyone that would purchase said unit. The prospect of changing batteries would deter some that would otherwise purchase a particular unit although to your point, might entice others.

The prospect of encountering a degradation of sound quality due to low batteries might be another deterrent.

If it were configured such that it would be charged when the unit is turned off and completely disengage the charging circuitry when the unit was turned on, an internal, rechargeable battery pack might overcome these concerns.

That it could be done is pretty obvious but you are correct in the fact that it would be a bit more complex than a switch on and off conventional AC unit.

The few obstacles are indeed the obvious need to charge and recharge the batteries. The batteries needed for an amplifier specifically would have to be the large capacity LiPo batteries that could easily provide the current needed.

The main Rail voltage could easily be whatever the design calls for by running the packs in series and LiPo batteries come in various configurations from 1S to 12S and no doubt could be made to order if need be.

The run time based on a few calculations I threw together would be easily in the few hours range of the typical wattage of an amplifier running at 30w average.

I don’t think the run time is a concern at all given enough real estate in the amplifier chassis or the battery power unit could be a separate chassis all together which I think is even better.

The charging part is not an issue, the smart charging technology today is not a concern and easy enough to incorporate into the battery unit chassis. A quality LiPo pack can be charged at 1C to 5C charge rates. About 35 min average for a conservative and safe charging rate of 1C.

The few obstacles I see is that the batteries do age with use, nothing lasts forever. As the internal resistance builds, the batteries will be prone to building up heat and degrading further.

The biggest concern is that while LiPo packs pack a wallop of energy density, they can also easily burn a house down if something goes wrong. It has happened enough times for anyone involved with the hobby of higher capacity LiPo packs to be extra careful and not leaving them unattended while charging.

I nearly caused a fire just by carelessly using a power cord that was rated at 10 amps while charging at 15 amps recently. Fortunately it melted and tripped a breaker when it shorted. The LiPo battery fire on the other hand would have been a disaster.

So besides a remote chance but a fire hazard possibility nonetheless, it is something to think about.

Then there is the battery life. Used daily, I can see the battery packs not lasting very long, perhaps a year or less at most as they all have only so many charge/discharge cycles in their lives.

So, perhaps some of these obstacles are indeed the reason we don’t see any battery powered amplifiers around.

The lower powered devices could easily be run on batteries and other less volatile chemistry batteries could be implemented in those devices such as phono stages, the Aurender and preamps.

[PHC1]

Originally Posted by jdandy

Aurender W20 music server review from The Absolute Sound.

https://www.theabsolutesound.com/art...usic-server-1/

I’ll have to read the article to see if there is any mention of battery type/chemistry. Thanks Dan.