What About LiFePO4 Batteries and Pure Sine Wave Inverters?


Lots of threads on dedicated AC circuits, but not much information regarding DC to AC battery driven systems. I never considered this as a power option because I assumed that the inverter would be noisy, but is this true? The setup is pretty simple where an AC/DC charger has the negative lead attached to the battery and the positive passes through an appropriate fuse on the way to the positive terminal. The on/off function can be a simple removal of the plug from the wall, or a smart wall plug. The charge state can be read from the charger, or you can add a wired, or Bluetooth battery monitor. The battery then feeds the inverter with a much larger fuse on the positive line to the input of the inverter. Your system is then plugged directly into the inverter, or at least your power conditioner is plugged into the inverter. Depending on battery capacity and system power usage, you can then run off the grid for many, or not so many hours. The problem is that it is difficult to find advice on such a power arrangement here on Audiogon. I’m just now putting together a system and I’m thinking that for better lithium battery life and shorter charge times, I want a larger capacity battery that I charge to 80%. I might also want an inverter that is oversize compared to the load that it experiences, in that most inverters turn on their fans when they reach 40% of their max power, or reach thermal trigger levels. The latter makes me think that mounting to a large aluminum surface might be thermally advantageous. Perhaps, someone that actually has some experience with this subject could offer some pointers.

vonhelmholtz

You ask about the inverter but never answer your question. I think that it will be very hard to find a commercial inverter that is not noisy simply because all loads other than high end audio don’t require a high quality inverter. And commercail audio is fine with bad power. So why would a manuafacturers waste money on it? The original inverters sold to drive skill saws from a truck battery were actually a square wave.

So I would confirm that I had an audiophile quality inverter before I spent a dime on anything else. The battery doesn’t matter at all for sound, it is all the practical concerns you mentioned.

And I agree you should ovesize the inverter, partly for quiet as you mention but also to esure you have the high power that quality audio needs.

I’ve offered for anyone with the popular battery backups being bought to bring one over and let my PS Audio Power Plant analyse it as an input. I get about 4% thd from the grid. I haven’t been able to test any inverters.

Frankly, I thing the major cost of the PSAudio power plants is the high quality inverter.

Jerry

So, with all of the many companies making audio oriented power equipment, why aren’t there high end inverters marketed for audio?  I would think that this either means that they are already available via products made for the general marketplace, or they are difficult/cost prohibitive to make.

Post removed 

Thanks for the information. I found this link:

Tweak Audio on Power Inverters

He  suggests a specific brand of power inverters and claims that just powering off the charger isn’t sufficient, but the charger should be disconnected from the battery during listening. Powering down the charger is easy to do remotely, whereas disconnecting and reconnecting the charger is more work and in my room, would require stepping over cables and moving around components. A WiFi power switch could be used to disconnect the charger.

Post removed 

I am really shocked at how little attention this subject gets. I am even more surprised when I consider that power is one of the top contributors to a great sounding system, or perhaps I should say that poor power is a certain road to a bad sounding system. There’s so many threads dealing with dedicated power lines and variations in system sound depending on what time of the day it is, yet so few people consider getting off the grid. There must be a reason that a battery powered system is not considered

Post removed 

I was introduced to this topic by someone with a system much higher end than my system. He has a better ear for small changes. So, I was impressed when he told me that getting off the grid made a noticeable difference. So, when posting this topic, I thought that other closet DC members would contribute, but this doesn’t seem to be the case. Regardless, I’m moving forward with putting together such a system. Unfortunately, as mentioned above, manufacturers don’t make inverters for high end audio, but some do claim low EMF radiation. All inverters seem to be rated at less than 3% THD. Nobody reviews, or compares inverters for high end audio. So, getting the right inverter is probably critical. I have yet to receive all the components. I do have all the electronics, and a giant cable cutter, so I’ll be getting out my soldering iron and drill this week and should be up and running.. oh.. I’ll be using a Synergistic Research A/C Power Performance Enhancer plugged into the inverter and a Shunyata Everest 8000 will handle power distribution.

Gary

I don't know if Living Voice will sell you just their inverter- they have been doing a serious battery array for big systems for years. May be worth reading up and giving them a ring (UK). 

The learning curve when putting your own battery/inverter system together is pretty steep.  The main goal is to not burn down your house and don’t fry your electronics.  To that end, understanding how cable gauge is determined is very important.  Also, it is pretty tough determining input power for components, but luckily power amps generally pull high power levels for short lived peaks.  Other than @whart  suggesting Living Voice, inverter selection for audio appears to be uncharted territory.  I’ll be using both Synergistic Research power treatment via Juan @blisshifi which plugs into an open power socket on the inverter and my Shunyata Research Everest 8000 to hopefully tame any digital hash that comes along with the “pure sign wave”.  Now waiting on cables. 

I’ll take the credit for telling @vonhelmholtz about how I took my whole system off the grid and implementing a battery supply. I got the idea myself from @ricevs replying to an inquiry of mine on GAN amps (thank you, Ric!), which led me to another thread on this forum of Class D enthusiasts who have gone off the grid.

My biggest hesitations at first were simply the risks of fire, leakage, or shock, and the pains of having to manage and charge the battery given that I have a high powered system that isn’t efficient like Class D. Once I got it set up, though, it’s been pretty easy to manage. Never once did I worry about the noise from the inverter, but I chose the Giandel 2000W model as I learned that most noise seems to occur if you utilize more than 40% of the power draw and fans kick in, etc.

That said, I am using both a Synergistic Research PowerCell SX conditioner, from which everything including my amps are plugged into the inverter, as well as one of their UEF AC Performance Enhancers, which is plugged in to the second AC output of the Giandel. As an authorized SR customer since 2014 dealer since 2023, I’ve found their power and grounding solutions to be exceptional and likely further reduce any noise generated from the inverter.

What I will say is this. Not only do I have dedicated lines, but I run those lines starting with a quality breaker. The cabling I’m using is $50/ft DH Labs Red Wave cabling, which is 10AWG of over 1,300 fine silver coated pure copper with advanced noise rejection properties, and high grade outlets. It was quite expensive to put in place, yet once I got the battery and inverter system in place, the improvement was immediately notable at a fairly dramatic level. Added blackness resulting in sonic clarity, snap, and definition of decay were the first attributes that captured my attention, but the soundstage also shifted and became wider and more spacious. I have demoed the differences for clients that come over as it’s easy to shut down the inverter, replug my system into the dedicated line, and start everything back up.

As another Audiogoner who visited me this past weekend stated, there was also no shortage of current considering my whole system was plugged into the inverter. He has asked for the shopping list of the system I built, and I told him I would update him based on the learnings Gary implements in his build. I like some of Gary’s directions on trickle charging and monitoring, which I will likely add to mine as my charger is pretty loud and annoying when in use.

I do keep the charger connected to the batteries at all times, but there is a hard switch to turn the charger off when not in use.

The cost of entry was pretty low considering what I spend on my reference system, so I thought the experiment was worth trying. At worst case, I could use the system for something not audio related, say when I am ready to install some solar panels and have backup reserves for when power goes out.

I’ll mention it here, now that Juan has made his entry. I went with a 3000 watt inverter vs Juan’s 2000. Also, his inverter advertises that it has low EMF. I went with a 300ah Lithium battery vs Juan’s 200ah. I did this as an attempt to keep the temperature down and the fan off. The downside of my approach is that Juan’s inverter is a known entity, because Juan uses it. My inverter is well rated, but most ratings are for those camping, or running a power saw in a remote location. The other pitfall of going with a larger inverter is that inverters are most efficient as they approach their maximum output, so I might find that my run time is negatively impacted. Lastly, if anyone else goes down this path, there are U.S. companies that makeup custom cables at reasonable prices. Once you enter your power parameters into a battery cable gauge calculator, you might be surprised as to how fast you work your way up to 4/0 gauge battery cable. First rule: No Fire!

I ordered my four cables for power (not charging) two hours ago and they just sent me shipping notification:  Custom Battery Cables

OK… after some mis-starts.. I’m up and running on battery.

With my system, on my utility/home wiring and with my power solution, which includes an Everest 8000, there is a night and day improvement in what I hear. It might be a bigger step up than when I added my Everest 8000. Everything is improved, dark background, dynamics, sound stage…Very simply sounds much like the performance is in the room. Juan described things and I had a show-me attitude, but trusted him sufficiently to spend the $1600. Best $1600 spent on my system, but you need to know what you are doing if you want to be alive to listen to the results. Power levels involved are nothing to take lightly. I’m not sure how to take this with respect to the Everest, but one of the main jobs of the Everest is to electrically isolate all components and adding it when on AC greatly improved what I was hearing. Interestingly, dynamics and speed are greatly improved and this carries over to the bass. The bass is much better controlled and very fast. I didn’t realize that I was missing anything. My inverter/battery are capable of putting out 20+amps directly wired to outlet, but as I have it setup, through the built in plugs, I’m limited to 15 amps.. but for some reason it is not the 15 amps plugged into the wall. As usual 300 watt/channel A/B power amp and 900 w/channed class D subwoofers plugged directly to their own channel on Everest.  I should mention, unlike Juan, I wasn’t on a dedicated 20 amp AC power line.

I’m up and running on battery.

Does your system sound as good in the day as night? There has been a lot of conjecture why stereos sound better at night than day. Battery could eliminate one variable.

Juan has more time listening. I’m new to off grid listening. As mentioned, I didn’t have a dedicated circuit. I no longer need to turn off air filters and lights in other rooms while listening. Also, no issue with last night’s thunderstorm and lightening. I have a whole house surge protector and my battery charger plugs into a large local surge protector. I don’t care if it’s “audiophile grade”. The charger is off while listening to music.

I’ll take this opportunity to mention that I have been leaving my components switched on and once the.battery is charged the charger trickle charges to support the system’s sleep mode.

For the few that care, I’m getting almost eight hours of play time on my 300ah battery. You can see my equipment associated with my profile. My charger is controlled by a KASA wall outlet. It charges and then provides a trickle charge. I turn it off to play music. While playing, the SmartShunt allows me to monitor the battery via Bluetooth. I have included below one page of information from the SmartShunt during playback.

Battery Monitor

 

Again, remember that some knowledge of simple electrical circuitry is required.  With unsafe practices, you can start a fire (main issue here is the cable gauge), or electrocute yourself.

@vonhelmholtz Looks like a user friendly control system.  I was a bit confused by your numbers until I realized your battery is 300ah at 12V.  So that is 30ah at 120V.  Your 238 watts is basicly 2 amps at 120V so you would be getting 15 hours at 100% efficiency so your inverter and other losses are costing you about 50% which I would say is about normal.

Glad you're finding it easy to use.

Jerry