Home Tech Marshall’s Stockwell III Stretches Its Battery to 40 Hours, and You Can Swap It Yourself
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Marshall hasn’t touched the Stockwell since all the way back in 2019. And in portable speaker years that’s roughly an eternity. Bluetooth standards, battery chemistry, and charging ports have all moved on, and the little amp-shaped speaker was starting to show its age.
Now the third generation is here, and Marshall wisely resisted the urge to reinvent the thing. The Stockwell III looks nearly identical to its predecessor, which is exactly the point.

The headline upgrade is the battery, which Marshall doubled from a respectable 20 hours to a frankly ridiculous 40. That’s enough to soundtrack an entire weekend without ever hunting for an outlet.

When you finally do plug in, it’s over USB-C. The battery even moonlights as a power bank, so a dying phone can borrow a few percent mid-playlist.

The bigger functional change is True Stereophonic 360-degree sound, which fires audio in every direction instead of blasting it straight out the front like a real amp would. No more sliding the speaker around the room chasing the sweet spot, because there isn’t one anymore.

A Dynamic Loudness feature handles the rest, quietly boosting bass and treble at lower volumes so the mix doesn’t go thin when you turn things down.

With right-to-repair rules looming in the EU, Marshall designed this one to come apart, and nearly every wear item is user-replaceable.
The battery, the front and back grilles, the silicone sleeve, and the carry strap can all be swapped when they wear out, which means a tired speaker no longer has to mean a landfill speaker.

Brand: Marshall
Model: Stockwell III
Drivers: One 3″ woofer, two 1.75″ wide-band drivers
Sound: True Stereophonic 360-degree
Battery Life: 40 hours
IP Rating: IP55 (dust and water resistant)
Connectivity: Bluetooth
Charging: USB-C (doubles as power bank)
Dimensions: 7.1 x 5.9 x 2.8 in
Weight: 2.9 lbs
Materials: Silicone sleeve, PU leather strap, brass control panel, metal grilles
Colors: Black and Brass, Cream
The Marshall Stockwell III is priced at $249.99 / £199.99 / €229.99 and is slated to land August 18, available through Marshall’s website and, somewhat amusingly, Costco. Head over to Marshall’s website for the full rundown.
Marshall Stockwell III
Marshall’s amp-inspired portable speaker returns after a seven-year hiatus with double the battery and a build you’re meant to repair, not toss.













