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Mozzoom

5000mAh Replacement Battery Compatible with JBL PartyBox 520 and PartyBox 720 & for Boombox4 Speaker, with USB-C Port (FG6CELL21700G)

  • Based on 3 reviews
Condition: New
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$72.98 Why this price?
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Availability: In Stock.
Fulfilled by Amazon
Arrives Oct 25 – Oct 26
Order within 13 hours and 44 minutes
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Features

  • Compitable DeviceSpecifically designed as a high-quality replacement for the PartyBox Stage 520, PartyBox Stage 720, and Boombox 4 Portable Speaker.
  • Battery Detail 21.6Volt, 5000mAh, 108Wh. Lithium-ion battery.
  • Versatile USB-C Charging & On-the-Go Power No proprietary charger? No problem. Featuring an integrated USB-C port, this battery can be charged via a wall outlet, laptop, power bank, or car charger. Weve included a USB-C charging cable in the box, giving you the flexibility to recharge your speaker battery anywhere, from the road to the living room.
  • Easy to installEasy to install and remove, includes an LED power indicator for quick charge-level monitoring.
  • Advanced Smart Chip Safety & Guaranteed SupportPlay with peace of mind. Our integrated smart chip provides comprehensive multi-protection against over-charging, over-heating, and short-circuiting. Your purchase is backed by a 1-year replacement or refund warranty and 24/7 dedicated customer service to ensure a worry-free experience.

Description

Battery for JBL PartyBox Stage 520/720 and Boombox4 Speaker,Replacement for JBL Battery 520, 21.6V, 5000mAh, Lithium ion

Number of Batteries: 2 Nonstandard Battery batteries required. (included)


Brand: Mozzoom


Battery Cell Composition: Lithium Ion


Recommended Uses For Product: Reclining Furniture


Unit Count: 1 Count


Number of Batteries: 2 Nonstandard Battery batteries required. (included)


Brand: Mozzoom


Model Number: 520/720


Model Name: battery replacement


Manufacturer: Mozzoom


Warranty Description: 1


Reusability: Rechargeable


Unit Count: 1 Count


Battery Weight: 1 kg


Antenna Location: Reclining Furniture


Battery Cell Type: Lithium Ion


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Oct 25 – Oct 26

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
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  • Zip Pay in 4
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  • Financing through Google Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Similar Products

Top Amazon Reviews

    • Easy Replacement That Brings the Speaker Back to Life
I picked this up as a spare replacement battery, and it fit my speaker without any surprises. Installation was straightforward, and once it was in place everything powered up normally. The USB-C charging feature is especially convenient because I don't have to keep track of a dedicated charger. I can top it off with the same cables I already use for other devices, which makes it much more practical. The battery has a reassuring, solid weight that makes it feel like a quality replacement rather than a cheaply made aftermarket part. Once installed, the connection to the speaker was seamless, with no pairing or recognition issues to deal with—it simply worked as expected. The battery indicator is also a nice touch since it's easy to see how much charge is left before taking the speaker out. Performance has been solid, providing the kind of runtime I expected for casual listening and outdoor gatherings. Considering the build quality, dependable connectivity, and added convenience of USB-C charging, I feel it offers good value for money if your original battery is wearing out or if you simply want a fully charged backup ready to go. ... show more
Reviewed in the United States on August 4, 2026 by Vine Reviewer
    • Doesn’t work that long
Only had it for a little more then 3 months and only charges 56%
Reviewed in the United States on September 10, 2026 by Saul anguiano
    • **Restored the Runtime of My JBL Portable Speaker**
This replacement battery is an excellent way to restore the portable playtime of a compatible JBL speaker without replacing the entire unit. If your original battery isn't holding a charge like it used to, this is a cost-effective solution. The battery fit my compatible JBL PartyBox/Boombox speaker properly and installed without any issues. After a full charge, the speaker was back to delivering long listening sessions with consistent performance. Charging through the USB-C port was convenient, and the battery charged reliably each time. The build quality feels solid, and the battery has performed consistently through repeated charge cycles. Replacing the battery is far more economical than purchasing a new portable speaker, especially when the rest of the speaker is still in excellent condition. Just be sure to confirm compatibility before ordering, as this battery is intended only for the specified JBL models. Overall, this is a dependable replacement battery that restores portability and extends the life of a compatible JBL speaker. ... show more
Reviewed in the United States on August 10, 2026 by Mictom

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