Battery power for ANY guitar amp

Here’s a question I’ve seen come up again and again: “Which battery-powered amp should I get?”

Fender Pro Jr. tube amp powered by a lunchbox-sized battery

In my past life as a software engineer, I learned this lesson quickly: asking the wrong question often yields the wrong solution.

In the early days, I’d nervously walk up to a more experienced engineer and start rattling off a hyper-specific algorithmic question, probably while fingering exact lines of code on the laptop cradled in my arms. My thought process was this: I need to prove that I have been really digging through the weeds and whittle my question down to something unambiguous to save their precious time while saving face. After some confusing back-and-forth I’d usually get the quizzical response, “what exactly is the problem you’re trying to solve?”

That, as it turns out, is first question I should have been asking. In the end, the more-experienced engineer would likely just google a term I had never heard of that precisely describes my problem, and present me with a handful open-source libraries (or a stack overflow post) that already solved it. Turns out all my prior digging was unnecessary. I got a better solution from a different angle.

In this case, the problem is perhaps this: I’m playing a rustic wedding ceremony while floating on an artisanal hand-whittled raft in the middle of a frog pond for a small audience of 50… this is purely hypothetical–I can’t swim and I’d probably turn down this gig.

In summary: I want to amplify my guitar without access to a power outlet. Now I might think, “clearly I need a battery-powered amp. Now which is the least-crappy sounding battery-powered amp and how much does it cost?” Wrong questions! How about: how do I power an amp without access to a power outlet?

With the same lithium battery technology used in electric cars and smartphones this is now possible in a package as small as a lunchbox.

These batteries are usually branded for camping/emergency use and include a standard 120V mains outlet. Various models are all over Amazon, but I got the cheapest I could find: a 222-watt-hour (update 8/29/2020: previous model no longer available) 250-watt-hour model (affiliate link) for under $200. It has one multi-international outlet with a ground pin, and one 2-prong outlet. It also has some handy USB ports for charging devices. I suppose the other benefit of these is you can use them for, well, camping and emergencies too.

250watt hour means you can power a 250-watt device for about one hour. So if your amp is 60 watts, you can power it for 4.17 hours. But the real figure is much more, because your amp probably only uses 60 watts at full volume. If you’re like me, playing at full volume, or even anywhere near it, never happens.

I’ve powered my AER Alpha for multiple 2-3 hour gigs without recharging. I’ve also put some 15-watt tube amps through it, like my Fender Princeton Reverb. I’ve even plugged in power strips and powered multiple devices. I’ve loaned it to a buddy who powered a PA speaker (QSC K10) with it.

The only issue I’d report is that there can be some noise interference due to the transformer in the power supply. Be sure to move it a few feet away from the amp. Also, single-coil pickups tend to hum more when not touching the strings since there isn’t grounding to speak of. If anyone knows a solution to this, let me know. Although, perhaps I’m asking the wrong question 🙂

If you MUST get a battery-powered amp, I’d recommend something from Roland’s CUBE series. They run on AA batteries for a truly impressive amount of time and volume. Don’t bother with stuff with heavy, proprietary sealed-lead-acid batteries. Guess what, if you forgot to charge it you’re out of luck. If some ubiquitous AA batteries ran out, you can solve that problem much more easily.

7 thoughts on “Battery power for ANY guitar amp”

  1. As a professional writer and semi-pro guitarist who plays lots of outdoor party settings… and someone trying to solve this exact problem… I would like to say that this is the best-written, most thoughtful answer to a common question that I have seen. Bravo and thanks.

  2. Please help! I (very cheaply, at least) purchased a Roland AC-60 amp, foolishly assuming that it would be AC-DC b/c my AC-33 has that capability. The news here about an external battery is quite encouraging and my only question: how does one use it w/the amp? Is there some kind of line out for alternate current? I’m hoping against hope and if the answer is no I probably will cancel my purchase…

    1. I think you might be overthinking this. Any amp with a wall plug should work fine with this battery. It’s basically a 120V AC power outlet in a box.

      Edit: If you’re confused looking at the jack on this battery, it does accept 3-prong AC power plugs. It might look weird because it’s one of those universal international plug jacks

  3. Hey man, I’m looking into getting a blues Jr for busking with a portable amp, Any idea how long this will last? Cheers =)

    1. This is all explained in the article, basically you take the watt hour rating of the battery (250 watt hour) and divide by the wattage of your amp (15 watts for a blues jr). That means it could potentially last 16.6 hour on a full charge. Though I have never put this to the full test. I can confirm I’ve run my pro jr. (Also 15w) for 3-hour gigs

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