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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.
Post Subject: LiFePo is very differentPosted by rickmcinnis on: 9/15/2022
And I wish I had looked more carefully before taking the cheap way out - which turns out to have become the more expensive way since I have no idea if anyone will buy a month old used battery.

From the graphs the traditional lead acid batteries all perform similarly - you get an initial period of full voltage that lasts depending on the load - but then declines in a linear way to the point where you should not go beyond for the likelihood of damaging the battery.

I go to 11.5 volts before turning things off.  I got a solid two hours last night after removing the SMPS powered components from the battery supply.  If the LiFePos allow four hours that is longer than i usually ever sit down to listen.

The LiFePo's curve looks like a sixth order Linkwitz Riley low pass curve - stays flat (in this case substantially flat) until you reach the "crossover point" and the fall is precipitous.  From what I read it does not ruin the LiFePo battery to be depleted fully.  Of course, the re-charging cycle is probably greatly increased.  There is also advice that taking them down too far will harm the life of the battery.  So not a good idea.

I have copied an illustration.  

Now I will find out what this means in reality when i install the LiFePos next week.

I have to repeat that once one hears what this does, not having the vagaries of the AC line, one would most likely not be able to return even with all of the inconvenience.  AC noise is much like digital noise - it infects the whole "note" - not a noise that resides alongside the note but something that intermingles with it.  One of those things you thought was just how it is until you find you no longer must live with it.

As Harry Pearson described the differences between digital noise and LP noise - the LP noise is distinct from the music signal and the brain can learn to disregard it.  The digital noise is impossible for the brain to disentangle.  When he wrote this I had lost my "faith" in Harry Pearson but that struck me as a insight he deserved to be lauded for.  Almost as great as when, in the early years of the magazine, he went on and on about how the Carnegie Hall renovation had bestowed a glassy sound on the Hall only for it to be discovered a decade or so later there had been tons of broken glass placed underneath the stage for some unknown reason.  Though I started out as an 18 years old reading the first issue of the magazine with mindless enthusiasm I had with time become far more cynical about Mr. Pearson's bulls.  But that allowed me to think the really had a fine pair of highly tuned ears even though he played fast and lose with other people's stuff.  Those long term equipment loans were a bit on the suspect side.  (don't know why the font changed.
There I go again ...

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