Been contemplating this for awhile, as I have sort of an irrational fascination with battery powered rigs. A few weeks ago, one of my credit card companies sent me a message to either use it or lose. Also, Jackery had a nice 15% discount over the Father’s Day weekend with a 1-year extension on the warranty. So I pulled the plug on a Jackery 300, which normally sells for $299.99 plus tax. I will probably never do a gig with it, but it will be nice to have the next time the power goes out.
I chose the 300 as I felt it provided the best balance of size, performance, and value. It’s fairly compact and weighs just over 7lbs. It’s rated for 300W continuous/500W surge. The battery is rated for 293Wh. The next step up is the Jackery 500 which weighs 13.32 lbs and is rated for 500W continuous/1000W surge. The next lower step is the Jackery 240, which is practically the same size/weight as the 300, and rated for 200W continuous/400W surge.
AFAIK the 240 is the smallest product Jackery sells with a pure sine output…so it’s the smallest I considered. One of my primary concerns was the power bank having a high enough surge capacity so the amp could turn on without pushing the pushing the power bank into protect mode. I was pretty confident the Jackery 300 would be up to the task.
The amp I envisioned using is my old GK 700RB/112 combo. This is a heavy old amp, but it has wheels and a telescoping handling, so you can drag it around like airport luggage. The woofer amp is rated for 225W with the internal speaker and 380W with an extension cab. It is rated to pull 615W at full power and 210W average. I assume this is with an extension cab, and the power draw will be lower with only the internal speaker.
When I pulled the Jackery out of the box it was charged to 57%. Plugged it in an let it charge up to 100%. When you turn on the AC outlet with nothing plugged in, it indicates that it is using 1-2W. The GK turned on without problems. The amp does produce a slight low-level, low-frequency hum when running on the Jackery. With the amp on and idling, the Jackery indicated it was supplying 22W. I played the amp as it was currently setup and it sounded normal. Then I cranked the amp up till it was barely clipping on loud transients. The Jackery indicated it was supplying about 50W. I don’t think I ever saw the meter indicate higher than about 52W.
I measured the AC output of the Jackery and it indicated 109.7V. The spec sheet says 110V. This was with the amp on and idling. I believe the amp will make slightly less power on 110V than it would on 120V. However, I put the amp back on the wall outlet and did not notice an obvious change in the power level.
I played for about 10 minutes with the amp near clipping, and the power reserve dropped down to 98%. With a 293Wh rating and a draw of 50W, the calculated run time is 5.86 hrs. However, the amount of Wh (Watt hours) a battery can provide varies somewhat with how fast you pull the power out. Pull it out too fast and the available Wh decreases.
AFAIK, the 293Wh rating is based on how much total power can be supplied over 20hrs. 293/20=14.65W continuous per hour (for 20hrs). If the amp is pulling 50W continuous, it is pulling the power out 3.4 times faster than was used for the rating. So the calculated run time would need to be downrated.
While playing the amp at high-volume, the Jackery’s internal fan came on. It’s noticeable if you stop playing, but nowhere near as loud as the fans in my vintage SVTs, so not a problem for me. The bottom of the Jackery became slightly warm to the touch.
For additional fun, I tried the Jackery with my Ashdown LB30 (Mk1). I think this amp pulls about 110W at idle on 120V. The Jackery indicated the amp was pulling 70W at idle and 74W when pushed into grind territory. So you could conceivably have an all-tube busking rig, although the run time would be a bit shorter. The amp sounded and performed pretty much the same as it does on wall power.
I think a 16.4lb Roland Cube Street EX would probably be a better choice for campfire gigs with a few acoustic guitars. But IMHO, the Jackery and a real amp like the GK 700RB/112 would be a way better choice for busking under most circumstances.
Jackery 300 in action with LB30 Mk1.
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