Portable power supply for amps or PA.

[One_Dude]

There are times, especially when playing outdoor, when there is no AC power available. For those times it would be nice to have a battery powered amp, or a DC to AC converter you can connect to a 12 volt battery. Battery powered amps seem to always have very low wattage output, with small speakers and don't sound very good.

I know there are few battery powered amps available that compare in sound quality to normal AC powered amps, so I have pretty much have given up on finding that kind of unit at any kind of reasonable price. A setup using a 12 volt car battery and a power inverter seems much more affordable. Since this is an arrangement that will not be used often, I don't want to spend a bunch of money. Does anyone here have a setup they use that they are happy with that doesn't cost many hundreds of dollars. I know there are small generators available, either gas or propane fired that will do the job, but I have played where those kind of units were used and they usually make enough noise to interfere with the performance. So what are your thoughts or experience.

Thanks in advance for your input.

Thump on,

One_Dude

 

[lug]

First you will need to figure out how many watts you will need (i.e what are you trying to power with it and how much power does that take to run). Once you figure that out, you will need what is called a pure sine wave inverter. You plug these into Google and you're good to go! My advice would be to double the power needed when choosing the inverter.

 

[Wasnex]

There are times, especially when playing outdoor, when there is no AC power available. For those times it would be nice to have a battery powered amp, or a DC to AC converter you can connect to a 12 volt battery. Battery powered amps seem to always have very low wattage output, with small speakers and don't sound very good.

I know there are few battery powered amps available that compare in sound quality to normal AC powered amps, so I have pretty much have given up on finding that kind of unit at any kind of reasonable price. A setup using a 12 volt car battery and a power inverter seems much more affordable. Since this is an arrangement that will not be used often, I don't want to spend a bunch of money. Does anyone here have a setup they use that they are happy with that doesn't cost many hundreds of dollars. I know there are small generators available, either gas or propane fired that will do the job, but I have played where those kind of units were used and they usually make enough noise to interfere with the performance. So what are your thoughts or experience.

Thanks in advance for your input.

Thump on,

One_Dude

If you want any significant amount of power for any significant amount of time, it's going to cost a significant amount of money and weigh a significant amount. .

There was a thread on Talkbass recently that eventually results in a home-built power bank that used a pair of 6V golf cart batteries wired in series. I believe this is it. Best Deep cycle marine batteries for mobile PA system

The first step is to decide how loud you need to be and what instruments you plan to push through the system.

Options:
1. Battery powered speakers
2. Use some sort of inverter or power bank
3. Use some sort of car stereo-based amplification system

I have participated in a lot of threads related to these options. So you should be able to find relevant threads by searching with the right keywords and my user name.

Here's a link with someone who assembled their own power bank.
Cableless setup from mixer to floor monitors.
If you search using his user name, you should be able to find posts where he identified the specific parts he used.

However at $527 you may want to just buy a pure sine power bank. Two quality brands I have looked at are Goal Zero and Jackery.

I believe Goal Zero's smallest pure sine power bank is the Yeti 500X. They used to make a 400 and 400 Lithium, but it looks that those have recently been discontinued. Goal Zero Yeti 500X Portable Power Station Yeti 500X Power Station

The smallest pure sine Jackery is the 240 Jackery Explorer 240 Portable Power Station If you have a small class D bass amp, I think the 240 should work fine.

 

[BassmanPaul]

To supply a band with AC power from a battery would need a battery the size of a truck. Far easier would be a Gas/Petrol generator. Remember it's isn't just the bass amp and PA but all members of the bands amplification equipment. There has been a quantum leap in battery technology in recent years but we are still far away from powering a band from batteries.

 

[One_Dude]

While it is not my intent to power the entire band from battery, my powered 8 channel mixer draws 800 watts AC , so any voltage converter capable of putting out more than that should have no trouble with the mixer. I have several powered mixers and one of my 4 channel mixers draws 150 watts AC. Bass and guitar amps draw varying AC wattage depending on their output power; my smallest bass amp draws 75 watts AC, and one of my highest output bass heads draws 900 watts AC. So theoretically there should be no problem powering an amp or powered mixer provided the converter puts out enough AC wattage. Powering an individual amp for each band member plus a high output PA would require far more AC wattage, and that is not my intent. I'm not talking about mega rock band stadium shows here, but more likely small outdoor venues with 1 to 4 players. For instance, check out Allie Sherlock on Youtube. She uses a small battery powered PA system that provides plenty of power for her busking needs. Since I already have PA systems and amps, I am looking for a way to utilize what I have by converting a 12 Volt DC supply to 110 Volt AC.

So my question is, has anyone found a 12 volt DC -AC converter that puts out enough 110AC power at say 1000 watts that is affordable and works well.

Thump on,

One_Dude

 

[Wasnex]

While it is not my intent to power the entire band from battery, my powered 8 channel mixer draws 800 watts AC , so any voltage converter capable of putting out more than that should have no trouble with the mixer. I have several powered mixers and one of my 4 channel mixers draws 150 watts AC. Bass and guitar amps draw varying AC wattage depending on their output power; my smallest bass amp draws 75 watts AC, and one of my highest output bass heads draws 900 watts AC. So theoretically there should be no problem powering an amp or powered mixer provided the converter puts out enough AC wattage. Powering an individual amp for each band member plus a high output PA would require far more AC wattage, and that is not my intent. I'm not talking about mega rock band stadium shows here, but more likely small outdoor venues with 1 to 4 players. For instance, check out Allie Sherlock on Youtube. She uses a small battery powered PA system that provides plenty of power for her busking needs. Since I already have PA systems and amps, I am looking for a way to utilize what I have by converting a 12 Volt DC supply to 110 Volt AC.

So my question is, has anyone found a 12 volt DC -AC converter that puts out enough 110AC power at say 1000 watts that is affordable and works well.

Thump on,

One_Dude

It's not just the ability to put out 1000W, you need the ability to put out 1000W for an extended period of time.

For an example look at the Jackery Explorer 1000. It's rated for 1000W continues with a 1002WH (watt hour) rating, and surge rating of 2000W. That basically means if your pulling 1000W average it will last about an 1 hour **. Keep in mind this is a $1,000 power bank.

** I say "about: because the WH a battery can produce depends somewhat on how quickly you pull the power out. My understanding is if you pull the power out slowly you will get more WH than if you pull the power out quickly. This paragraph explains:

An amp hour (AH) is a rating usually found on deep cycle batteries. The standard rating is an amp rating taken for 20 hours. What this means for a 100 AH rated battery is this: Draw from the battery for 20 hours, and it will provide a total of 100 amp hours. That translates to about 5 amps an hour. (5 x 20 = 100). However, it's very important to know that the total time of discharge and load applied is not a linear relationship. As your load increases, your realized capacity decreases. This means if you discharged that same 100 AH battery by a 100 amp load, it will not give you one hour of runtime. On the contrary, the perceived capacity of the battery will be that of 64 amp hours.​

Source: Battery Basics - Guide to Batteries | BatteryStuff

Here is a calculator that allows you to convert from AH to WH and vice versa.
Convert Amp hour to Watt hour (Ah to Wh)

For example, the Jackery Explorer 1000 has a 21.6V battery with a 46.4AH rating. If you put these figures into the calculator, you will get the 1002.24WH. I believe this 46.4AH rating is for 1hr, rather than 20 as described in the paragraph above...sorry this stuff gets complicated.

Here's another page, the will either confuse or inform you: Understanding Battery Amp Hours

It basically says AH can mean the amount of current a battery can provide in one hour, our there may be a "C" rating that specifies a duration like 5 hours, 20 hours, or 100 hours. Deep cycle batteries generally have a C20 rating.

This article also explain why a battery can provide more energy as it runs longer at a lower current.

 

[Jazz Ad]

Using power supply with gear designed to run off wall AC is a bad solution. Not enough protection, too much energy wasted in conversion.
Use a portable PA. There are many nowadays and they're not even expensive.
A JBL Eon One for example is 120w with Bluetooth, 4 channel mixer complete with effects and bluetooth, for 600 or so.

 

[SteveFromBerlin]

There's a somewhat new trend in the camping field... portable batteries that can deliver clean sine waves and won't hurt your electronics! You can charge them via solar power, car cigarette lighter or mains socket.

I have a PowerOak 500 which delivers up to 300 Watts. I played a couple of shows using a GK 700RBii and a big fat 212 cab... after about two hours, I still had 80% battery left. I just love it!!!

The bigger the cab, the less power you'll need.

By the way: That GK is a beast and seems to have a very clever usage of power.

 

[One_Dude]

Thanks to WASNEX for all the info, it makes sense when I read the links you provided. And also thanks to Jazz Add; I have been looking at small battery powered PA systems, but at this point can't justify spending very much. As the Covid continues that may change.

There's a somewhat new trend in the camping field... portable batteries that can deliver clean sine waves and won't hurt your electronics! You can charge them via solar power, car cigarette lighter or mains socket.

I have a PowerOak 500 which delivers up to 300 Watts. I played a couple of shows using a GK 700RBii and a big fat 212 cab... after about two hours, I still had 80% battery left. I just love it!!!

The bigger the cab, the less power you'll need.

By the way: That GK is a beast and seems to have a very clever usage of power.

Thanks Steve From Berlin, I have exactly the same GK bass head that you mentioned. I have also done some reading about battery fed converters using solar cells to help support the battery. As you said, this arrangement seems to be gaining popularity in the camping community. I have also read that long haul truck drivers are using the same setup to power the small appliances in their sleeper cabs.

As for converters, there seem to be two basic design options; pure sign wave, and modified sign wave. The difference being a pure sign wave closely resembles the AC sign wave from a typical household electrical outlet, whereas the modified sign wave converter puts out a square AC sign wave. The modified sign wave converters are cheaper to buy, but are thought to be less efficient and can cause any powered device to work harder. There is also an issue of sometimes inducing a "hum" into an audio device that is being fed. I looked at the PowerOak 500 online and it seems to be primarily for the European Market, and I could not determine if it is a pure sign wave unit or a modified sign wave unit. Based on its price I suspect it is a pure sign wave unit; do you know for sure?

Thanks again guys for your input.

Thump on,

One_Dude