Outdoor - Portable Power Station - Sine Wave?

[Jaspla]

There are a pile of low power, lithium battery based, portable power stations out there. Looking for a lower priced unit that can supply about 200-250W for outdoor, busking performance of keyboard and a low power amp (60W or so)

 

I know a 250W unit should give 3-4 hrs of performance, but am trying to figure out if a pure sine wave power station is actually needed, or if modified sine wave (or other), which typically cost less, are OK

 

Considerations would be possible damage to amp or keyboard, and any 'line noise', buzzing that might be created with a power bank that does not provide a pure sine wave

..might also be doing some vocals thru the amp, so 'power station noise' would be of concern.

 

Both the keyboard and the amp being use use external power modules to convert AC to DC for the respective board or amp

 

..your experiences using these, suggestions....

[Konnector]

Pure sine wave for electronic gear. Modified sine wave = dirty power. Good clean power comes at a price. Use the cheap ones for power tools.

[Polychrest]

Pure sine wave for electronic gear. Modified sine wave = dirty power. Good clean power comes at a price. Use the cheap ones for power tools.

+1

From experience with small off-grid solar systems, electronic gear runs hot and noisy with modified sine wave inverters, especially cheaper low-power ones.

[Delaware Dave]

To the OP, can you provide a couple of links to the lithium battery based, portable power stations that you looked at; it helps to get a better feel for specifically what you were looking at.

[Tom Williams]

You may want to check the assumption that a nominal 250 watt supply is good for 2-3 hours. Many Uninterruptible Power Supply (UPS) units are designed to provide at most 15 minutes' time at rated output.

[Jaspla]

Appreciate the comments so far. Am most interested in knowing if anyone has actually used any particular brand of 250W or less power stations successfully (with no smoke) that ARE NOT providing sine wave power.

 

As I had noted, the amp and keyboard I would be using use power packs that convert AC to 12-16V or so DC. So the brunt of the 'damage' from a non sine wave source would likely be to the external power pack, or some resulting line noise. I am inclined to think pure sine wave is the best choice, and would not risk plugging in keys or amp with internal power supply if the power source was not sine wave.

 

However there are a gazillion 'power stations' available at lower prices on the big name (starts with A) on-line eCommerce company site.

...if you type in your favorite search engine or eCommerce search box "portable power station pure sine wave" you see a ton of products, however, as an example I saw a unit listed for just under $100 that stated 'pure sine wave', however 1) no PDF was listed 2) when I located the 'manufacturer's' web site, I saw what appeared to the the similar product, no mention of sine wave, no PDF manual, and as I looked at their other product lines I saw trampolines, weight lifting equipment...NOPE.

 

..as you can see, credibility is an issue, and with such a large collection of suppliers (that you've never heard of), its hard to determine which companies are providing the trusted products.

 

....search engine sites, that provide a link to 'Best Portable Power Stations for 2021', usually show you a list of units, all noting that your refer to 'A's" site to check the latest price, where you know someone is making a 'nickel' off all the forwarded links....no credibility there. YouTube...lots of reviews, lots of products are 'liked'...and you are provided a link...usually to 'A's' site to check the latest price....

 

Seems like it doesn't matter if you're inclined to spend $300 or $125, you still have to deal with such a large collection of vendor brands, and very little understanding of which ones might be most reliable, and accurately described.

..if most of us saw vendor names like Roland, Yamaha, Casio, Kurzweil, Sony, Honda etc. We might have some level of confidence...

[Tom Williams]

I used to mess with batteries and inverters a lot in a previous occupation, and I am 4 weeks into a UPS-centered project. So, I offer a couple more bits o' wisdom:

• Gotta reiterate, a consumer-oriented power unit that says "1500 watts" is talking about 1500 watts for between 5 and 15 minutes, just enough time to shut down cleanly.
  
• The bulk of consumer-grade UPS's are sold by APC and Tripp-Lite. The second one has a much longer history of power backup and conditioning.
  
• So the main advantages -- and they are real -- are (1) power conditioning and (2) momentary loss of power.
  
• Lithium-based UPS's cost 4-6 times as much as lead-acid units.
  

[bourniplus]

Many years ago when I put together my busking setup I used a cheap, modified-sine-wave inverter that caused some annoying noise. I bought a 600 watt, pure sine wave inverter from China and it solved the noise problem. It doesn't seem to really have a brand other than "Power that really moves"...

[JimboKeys]

As others have pointed out, the 250W rating of the units you are considering doesn't really address how long it will operate at that level. That's determined by the Amp-hr rating of the power pack.

 

For a real world example: I've been using a lead-acid type power pack (the kind you'd find at a big-box hardware store) rated at 22 Amp-hours at 12VDC, which i run into a pure sine wave inverter. Taking into account the less-than-100% efficiency of the inverter and allowing for aging of the battery, i'd put the actual energy available at a conservative 15 Amp-hr. 15 Amp-hr at 12V works out to be 1.5 Amp-hr at 120V. So as long as i keep my total power requirement to below 60W (0.5A * 120V) i can get through 3 hours of playing (3 * 0.5 = 1.5).

 

A few things i've found: the inverter i'm using is rated for 400W - i think this helps to keep the inverter from conking out during periods of peak current draw. In fact, i found i had to power up the speakers (two ZxA-1's) before the keyboard and mixer, as the power-on inrush current for the speakers caused a sufficient transient voltage drop that would put the other electronics into a non-operating state until rebooted.

 

Also, don't worry too much about trying to meet the power spec on your devices - for example, the ZxA-1's are spec'd to draw 0.6A each, but at a moderate output level the current draw measures about 150mA per speaker.

 

- Jimbo

[OB Dave]

As I had noted, the amp and keyboard I would be using use power packs that convert AC to 12-16V or so DC.

Instead of using an inverter to convert a battery to 120vac only to step it back down to 12 volts DC, why not completely eliminate the middlemen and just run your whole setup off 12 vdc? Go to Costco and buy a Deep Cycle Marine/RV Battery. Cost you about 90 bucks and you wire it up to power your keyboard and amp directly, assuming those both run off 12 vdc. A battery like that will be rated at about 100 amp-hours.

[stoken6]

As I had noted, the amp and keyboard I would be using use power packs that convert AC to 12-16V or so DC.

Instead of using an inverter to convert a battery to 120vac only to step it back down to 12 volts DC, why not completely eliminate the middlemen and just run your whole setup off 12 vdc? Go to Costco and buy a Deep Cycle Marine/RV Battery. Cost you about 90 bucks and you wire it up to power your keyboard and amp directly, assuming those both run off 12 vdc. A battery like that will be rated at about 100 amp-hours.

This x120 (x230 in Europe). None of those pesky sine waves to worry about.

 

What keyboard and amp are you using? Some amps labelled "60w" draw 180w, some draw 20w. The keyboard probably draws 10w or less.

 

I was going to suggest a powerbank with a 12v output (not materially different from a 12v battery, just with some charging electronics and displays/LEDs) - they do exist, but rarer than the 5v USB jobs. Depending on which amp you use, the capacity of the powerbank/battery will vary.

 

Cheers, Mike.

[Reezekeys]

Also, don't worry too much about trying to meet the power spec on your devices - for example, the ZxA-1's are spec'd to draw 0.6A each, but at a moderate output level the current draw measures about 150mA per speaker.

That looked like a typo to me so I had to check - yes, the spec sheet says those ZXA1s draw .6A, however the fine print says "at 1/8 power" which appears to be some kind of standard measurement because that same "1/8 power" is how my old QSC K8s' current draw is listed. However my speakers draw about 2 amps at that power level! Sounds like those ZXAs would be an excellent choice for a battery-powered rig.

[Delaware Dave]

As I had noted, the amp and keyboard I would be using use power packs that convert AC to 12-16V or so DC.

Instead of using an inverter to convert a battery to 120vac only to step it back down to 12 volts DC, why not completely eliminate the middlemen and just run your whole setup off 12 vdc? Go to Costco and buy a Deep Cycle Marine/RV Battery. Cost you about 90 bucks and you wire it up to power your keyboard and amp directly, assuming those both run off 12 vdc. A battery like that will be rated at about 100 amp-hours.

 

Or something like this:

 

https://www.ebay.com/c/1031505818

[RandyFF]

There are 2 measurements going on.

 

1) 250 watts is talking about the built-in inverter. The 250 watts is the continuous capability, and then there's the peak (which is often twice as much). The peak is also important as some devices have high start-up voltage requirements that last only a second or so.

 

2) The actual power of the built-in batteries is rated in watt hours (wh) for these lithium ion batteries (which are not 12v, I believe they're 3.7v) .

For 12 volt DC batteries the power is listed as amp hours (ah). So for what you've described, look for the wh ratings

 

I used to play several times a week outdoors with a QSC K8.2. At first I used a marine/deep-cycle lead acid battery. Cost me about $160 with tax for a 70 amp hour battery. Heavy as F, about 50-60 pounds?, and I had to use a separate inverter. Big hassle, way too heavy and cable-y.

 

Eventually bought a lithium ion battery/inverter. Weighed about 6 pounds: 250 wh battery, 300 watt inverter.

Worked surprisingly well considering what a powerhouse the K8.2 is, esp as you crank up the volume and bass. But I always ran into the problem of the whole system shutting down if I got too loud or had too much bass going. Didn't seem to hurt anything, but it meant I had to power everything back up.

Over the course of 3 months or so, this 250wh battery would shut down even at moderate volume. It's hard to know which is failing/shutting-down, when you've got the battery and inverter built into one unit. I assumed it was the battery was failing, but it could have also been the inverter.

That battery/inverter cost me $130, which was a great deal, normally for 250wh you'd pay $200 or over.

 

My conclusion was that for my use I needed to get more than the bare minimum needed. If I was playing outdoors again with that speaker, I'd want to get a unit with 400-500 watt hour capacity, with the inverter at 500-600 watts, so double what I was using, about $400-500, and double the weight. Keep in mind these were outdoor jam sessions in the park, sometimes with 20+ drummers, so I was playing very loud sometimes. If your volume is more moderate, your requirements go way down.

 

For your use with a low powered speaker I'd guess you could get away with a 200wh battery with a 250 watt inverter. So around $150. I found Amazon to be a good place to comparison shop.

 

 

There's another thread I'm not finding started by a guy looking to play on the streets. I went into even greater detail, but unfortunately I'm not finding that thread.

 

You might also consider the JBL Eon One Compact, which has a battery built-in. $549 though. Fantastic unit, simplifies everything cause with BT you can play backing tracks streaming from your phone. It also has extensive EQ and FX, and two mic inputs, including support for condenser mics. It's the unit I've been waiting for many years! And with BT mixing, I can use my smartphone to dial in my levels- brilliant!

[Jaspla]

I again appreciate the stream of ideas and suggestions. Responding to some of them - My Kurz keyboard needs 15v, my PX-5s can run off 12V, one of my amps the Roland KC-110 needs 13V...so trying to come up with a DC solution would not easily work. The watts required by either of the keys is around 15W or so. Lets say I use the KC-110 Amp which is 30Watts, unless I red-line it with constant bass notes, it's likely cruising at some 20W. With this one keyboard/amp combo (15W+20W total), I would anticipate you could get 3 hours play time off a 250W rated unit, assuming some loss of efficiency and power degradation over the 3hr period.

 

I do have a 600W sine wave inverter and marine battery...which I no longer want to drag around. Thats why the consideration of a lithium ion based Power station (these lithium based units are compact; usually weight less than 10lbs)

 

Specifically commenting on RandyFF's reply...with the 250W lithium unit you used, was it noted to have sine wave AC? Noted your mention of running the QSC off the unit, but was not sure if you were also doing keys. Other than the cut-outs due to power demand (and your observation that you should go for a higher power rating)...was the unit satisfactory? Brand?

..also I could very see if you're punching up a bunch of bass notes, unit running time would likely drop.

[RandyFF]

The watts required by either of the keys is around 15W or so. Lets say I use the KC-110 Amp which is 30Watts, unless I red-line it with constant bass notes, it's likely cruising at some 20W. With this one keyboard/amp combo (15W+20W total), I would anticipate you could get 3 hours play time off a 250W rated unit, assuming some loss of efficiency and power degradation over the 3hr period.

 

I do have a 600W sine wave inverter and marine battery...which I no longer want to drag around. Thats why the consideration of a lithium ion based Power station (these lithium based units are compact; usually weight less than 10lbs)

 

Specifically commenting on RandyFF's reply...with the 250W lithium unit you used, was it noted to have sine wave AC? Noted your mention of running the QSC off the unit, but was not sure if you were also doing keys. Other than the cut-outs due to power demand (and your observation that you should go for a higher power rating)...was the unit satisfactory? Brand?

..also I could very see if you're punching up a bunch of bass notes, unit running time would likely drop.

 

Jaspla,

So are you playing solo? Vocals? Just keys?

 

Pretty much every lithium battery with inverter 'power station' I came across used a sine wave inverter. It'll say it right in the ad, so no big thing to worry about. Sine wave is the way to go if you can, is more gentle with electronics.

 

You realize the QSC K8.2 is one of those new monster speakers that is rated at 2000 watts, right? Actually AFAIK, it's more like 1,000 watts continuous, but even that's nothing to go by. I actually ran another speaker, the Turbosound IP300 off of it, rated at 600 watts (300 continous), and it made just as big of a demand on the battery/inverter as the K8.2 did, so go figure. There are ways to compute this from the ratings on the speaker of how many amps it takes, but I never figured that out. I was pleasantly surprised that my 250 WATT HOUR (not just watt) lithium battery would power the K8.2 so well. But in the end it didn't, with any system like this that you push to the limit you need a reserve. In my case, twice as much battery and inverter capability.

 

You said,

"Noted your mention of running the QSC off the unit, but was not sure if you were also doing keys"

Yes, the battery/inverter ran the QSC speaker, and also powered my keyboard that was playing thru the speaker.

 

It's a Picowe. I'm guessing it could never be satisfactory for how I was trying to use it, and I'm guessing I damaged the unit, because after 3 months of using it 2-3 times a week, it went overnight from running the K8.2 for 2-3 hours at decent/loud volume, to hardly running it at all.

 

All of this is just speculation. The portable lithium battery/inverter market is pretty new, and as I've heard from multiple sources, most of these units are made as cheaply as possible in China. The next time I would buy a little more conservatively (more power than I anticipate needing) and by a reputable company, not just the cheapest.

 

Don't you just love playing outdoors! I did it for years in Golden Gate Park in SF. Was sweetness itself to be in a beautiful natural setting and playing music with drums and guitars.

[Reezekeys]

You realize the QSC K8.2 is one of those new monster speakers that is rated at 2000 watts, right? Actually AFAIK, it's more like 1,000 watts continuous, but even that's nothing to go by. I actually ran another speaker, the Turbosound IP300 off of it, rated at 600 watts (300 continous), and it made just as big of a demand on the battery/inverter as the K8.2 did, so go figure.

I can't tell from your wording if you realize that the acoustic power output of an amp is a completely different spec than its power consumption.

[RandyFF]

You realize the QSC K8.2 is one of those new monster speakers that is rated at 2000 watts, right? Actually AFAIK, it's more like 1,000 watts continuous, but even that's nothing to go by. I actually ran another speaker, the Turbosound IP300 off of it, rated at 600 watts (300 continous), and it made just as big of a demand on the battery/inverter as the K8.2 did, so go figure.

I can't tell from your wording if you realize that the acoustic power output of an amp is a completely different spec than its power consumption.

I was just talking about the disparity between published wattage specs, and how long and hard I could drive these two very differently rated speakers that ranged from 1000 continous watts to 300. Turned out both seemed to use about the same amount of battery power. Yes, speaker efficiency figures in this, I wasn't addressing that.

 

I know next to nothing about figuring this stuff out. What do you mean about acoustic power output of an amp vs its power consumption? And how do you figure out if the battery/inverter 'power station' watt hours are sufficient based on the specs of the speaker? And for that matter, if the built-in inverter will handle the loads presented?

[Reezekeys]

From your earlier post it looks like you have a good handle on this - so you do seem to know a lot more than "next to nothing"! I was only referring to how active speakers' amps are rated in term of their output, which is usually at a certain distortion level, versus the current their electronics draw, which is the actual determining factor in how big a battery & inverter setup you'd need. The two numbers are correlated to some degree since a louder undistorted ouput needs a more powerful amplifier which will draw more current - but amps differ greatly in design classes so it's not as simple as a "2000-watt rated output" speaker needing a set size of inverter/battery to function correctly. And of course you're adding another variable, which is an amount of time you need a battery to supply said power.

[Jaspla]

RandyFF, thanks for identifying the unit you tried and your experiences "It's a Picowe" - and thanks all - for your thoughts....

At this point I believe I will 'wait out' developments on these portable power stations, and plan to utilize my 600W sine wave inverter, and maybe find a more lightweight and compact motorcycle battery.

[RandyFF]

From your earlier post it looks like you have a good handle on this - so you do seem to know a lot more than "next to nothing"! I was only referring to how active speakers' amps are rated in term of their output, which is usually at a certain distortion level, versus the current their electronics draw, which is the actual determining factor in how big a battery & inverter setup you'd need.

 

The two numbers are correlated to some degree since a louder undistorted ouput needs a more powerful amplifier which will draw more current - but amps differ greatly in design classes so it's not as simple as a "2000-watt rated output" speaker needing a set size of inverter/battery to function correctly. And of course you're adding another variable, which is an amount of time you need a battery to supply said power.

Reezekeys,

Hmmmm.... have never heard that before. Just looked at the back of my K8.2 and found no numbers listing their power draw / amp / whatnot.

 

From their website:

> AC Power Consumption 1/8th Power*

* 1/8 power is representative of current draw with typical music program material with occasional clipping.

> 100 VAC, 2.1 A / 120 VAC, 1.9 A / 240 VAC, 1.1 A

 

So does these specs tell me what I need to know about buying a battery/inverter?

[RandyFF]

RandyFF, thanks for identifying the unit you tried and your experiences "It's a Picowe" - and thanks all - for your thoughts....

At this point I believe I will 'wait out' developments on these portable power stations, and plan to utilize my 600W sine wave inverter, and maybe find a more lightweight and compact motorcycle battery.

 

Jaspla,

Keep in mind that sigificant discharge of a battery is why deep cycle batteries were made. The typical car/motorcycle battery is meant to start the vehicle, but beyond that the alternator tops up the battery, so not much discharge going on. If you repeatedly deeply discharge a car/motorcyle battery, your longevity takes a big hit.

 

Whereas a deep cycle is just as its name implies, you're able to do the deep discharges and not ruin the battery. I suppose deep-cycle/marine battery comes from using them for small fishing boats motors that rely on the battery for all power.

 

If your budget ever allows, take a look at the JBL eon one compact- amazeballs speaker, does so much for the busking/portable musician.