Power Bank for a Joya BA-30 Amp? What do I need?

[dBdB]

I am thinking about buying this little amp for an acoustic bluegrass meetup group. Amazon has the amp for $90.
It can run on a power bank.
Their site says to use this type power bank.
"USB Type-C power banks (PD 2.0+ 65W+ required). Note: Requires continuous power connection - no internal battery."

Can someone tell what Power Bank I need to buy for this on Amazon?
I'd like to get 3 hours on the amp with the power bank.

Thanks

 

[Kenny056]

I am thinking about buying this little amp for an acoustic bluegrass meetup group. Amazon has the amp for $90.
It can run on a power bank.
Their site says to use this type power bank.
"USB Type-C power banks (PD 2.0+ 65W+ required). Note: Requires continuous power connection - no internal battery."

Can someone tell what Power Bank I need to buy for this on Amazon?
I'd like to get 3 hours on the amp with the power bank.

Thanks

I just picked up one of these. Im not sure if its what you had in mind, but it works great for me. I saw someone on here recommend it and i jumped on it when Amazon had a sale.

https://a.co/d/bwUwClm

 

[96tbird]

You need a power bank that has USB C PLUS THE 65 part. Anything with those specs will power it

Now to last 3 hours you need to know the battery capacity. The one Kenny056 showed you is rated at a capacity of 81000mAh. That's 81 amp hours (Ah), in other words it can deliver one amp of draw for 81 hours. So we then need to find out how much the amp actually draws.

Max output is 30watts. Let's say we split that in half because music is transient and moves from 0 watts up to 30 watts. So 15 watts average. Assuming 5 volts we would be drawing 3 amps to yield 15 watts. This is only using assumptions because we don't know enough about what's really happening in the amp, data isn't provided and there's a ton of other factors. Especially in an amp where actual power draw in amps vs net output in watts has a bunch of electronic components wasting energy as heat.

So 3 amp average draw and 81 amp hours. 81/3 =27. That bank can supply 3 amps for 27 hours continuously.

Although this is in no way anything than an estimate and assumptions may not be true, I would say the bank our friend suggested will do a good job of powering you for 3 hours. Unplug it when you take a break to conserve your charge.

As I said variables and lack of data drive this very rough estimate. The only experience I have is in the electric RC aircraft motor area. In those cases, it's a much simpler circuit and we have all the data we need to calculate what size (mah) battery we need and calculate how long runtimes can be expected. So I'm fudging this without sufficient data, but an 81 Ah battery should be plenty.

 

[blr2]

Several things to point here:

1. The suggested PB will cost way more than the amp itself.
2. Calculating run times, it should be noted that many PBs state the total capacity of the cells inside. This is not the same as the capacity they can deliver at their regulated outputs. At least you should factor the efficiency of the voltage converters (typically 70-75 %).
3. We don't know what voltage the amp needs to operate. Most probably there is another converter in there.

 

[Kenny056]

I just looked at the listing for the one I have and saw that there is a 150 watt model. It has just one AC outlet but still offers USB C. It's a good bit cheaper as well. Its the only power bank like this that ive used but so far its been great. There are tons of these types of banks available so im sure you'll find something that fits your needs.

 

[dBdB]

Thanks for all the info, folks.

I have an old Duracell Powerpack Pro 1300 that surprisingly still works. I got it 10 years ago to power a GK MB 150 combo amp with the 12" metal extension cab. I also used two small Fender Rumbles, a 25-watt and a 40-watt. The maximum usage time I ever did was four hours, and it still didn't run out of juice. After three years, the internal wet battery died, and I bought a new one in 2018 on Amazon for $30 and replaced it myself.

I used this from about 2015 to 2020, when Covid hit, and that little weekly gig ended at an organic farmers' market. Last Sunday, I tried the Duracell again with the Fender Rumble 40. I ran MP3s into it, turned the amp up loud, and layed it flat on the carpet with the speaker down to muff the sound. After five hours, it was still blasting.

I remember years ago, I also used a larger Ampeg amp with it. It was fine, too. The only issue was with a MarkBass Amp. It would buzz.

So, I guess until this Duracell finally bites the dust, I can keep using it for this bluegrass group along with the Fender Rumble 40.

To get this Duracell setup 10 years ago, I met a guitar player who worked at their main plant. He told me about it and said, 'When not using it, keep it plugged in all the time.' He mentioned that every three years, the internal battery would probably die, but it is pretty easy to change.
He was right about the three-year mark. In 2020, I stopped using it but still kept it charging full-time. It's crazy that it still works!

Another benefit of the Duracell is that it has jumper cables to charge your car battery, a compressor to pump your tires, two huge flashlight lights, and two USB ports to charge your phones.
Ha-ha!

It was this Duracell: Amazon.com
and ths was the replacement battery: Amazon.com

 

[agedhorse]

On average, for a small amp, dividing the audio power (rms units) in half will be plenty close enough to account for losses in the real world power consumption. If you use 7.5 watts as power consumption, you will be fine.

A 100W rated capacity power bank will be fine, do will a 75 watt.

 

[blr2]

The cheapest will be to buy a new Pb-acid battery for your existing unit. It will be heavy though.

 

[dBdB]

Right- that is exactly what I did before. I have had the newer battery in there for over 5 years, and it still works.
And yes, the whole deal is heavy because it also has the big attachments like the tire pump and jumper cables.
It was 2015 technology, and it was great back then. I'd like it all to be smaller and lighter these days.
The Duracell is rated at 600 watts is why I was able to use larger bass amps with it for long periods. (I guess).
Now that I tested it for 5 hours and it still works, I guess I will keep using it with the smaller Fender Rumble 40-watt until it goes dead.
Then I'll buy one of those smaller power banks on Amazon.

Thanks to all for your input.

 

[blr2]

Something like this:

Pardon Our Interruption...

Or with similar specs may work. It will be much smaller and lighter, but don't expect the same performance as what you already have.

 

[agedhorse]

Just be careful with these, there have been issues with some catching fire and if this happens they are EXTREMELY difficult to extinguish.

Try to find one with a UL, CSA, TUV safety agency listing.

 

[blr2]

Just be careful with these, there have been issues with some catching fire and if this happens they are EXTREMELY difficult to extinguish.

Try to find one with a UL, CSA, TUV safety agency listing.

Oh yeah, lithium fires are tough to extinguish. There are extinguishers for this purpose. Lead-acid batteries are much safer in this respect, but the weight energy density is only 1/4 compared to Li-based chemistries.
I only pointed to a spec, not a particular product. I haven't used this particular one, and the internet is full of junk.