JBL Battery 400 Replacement Battery for PartyBox Stage 320 and Xtreme

In this review of the JBL Battery 400 replacement pack, the bottom line is straightforward: this battery is for owners of the PartyBox Stage 320 or Xtreme 4 who need a high-capacity, reliable replacement that restores long portable playback. The reviewer found the 10000 mAh pack delivers extended run time and sensible safety features, and that installation is straightforward with basic tools. For anyone wanting to avoid frequent recharges during events or outdoor use, this battery addresses the single biggest concern-playback endurance-while matching the form factor and connection style of the original unit.

Key Features

• High Capacity: The 10000 mAh (74 Wh) capacity provides significantly longer playtime per charge, helping reduce interruptions for portable parties or long listening sessions.
• Long Cycle Life: Designed with cycle protection and quality testing, the pack is claimed to last more than 1000+ charge cycles, which improves long-term value over cheap replacements.
• Built-in Safety: An intelligent protection chip guards against overcharge, overdischarge, short circuit and overheating to reduce risk during everyday use.
• Compatibility: Formulated as a direct replacement for PartyBox Stage 320 and Xtreme 4 portable speakers, so it fits the intended models without modification.
• Easy to Install: The compact pack is installed using a Torx T20 screwdriver for straightforward swap-out of the original battery (screwdriver not included).
• After-sales Support: The product includes a 12-month warranty and vendor support to help confirm compatibility and resolve issues after purchase.

Who It's For

This battery is ideal for PartyBox Stage 320 and Xtreme 4 owners who use their speakers for extended sessions outdoors, events, or mobile DJ work and need a dependable replacement that restores or extends runtime. The larger 10000 mAh capacity is especially useful for users who want up to around 19 hours of playback per battery in real-use scenarios and value longevity from more than 1000 charge cycles.

It is not for people who expect tool-free, instant clip-in swaps; installation requires a Torx T20 screwdriver. Also, buyers who need a different form factor or a speaker model other than the listed two should look for a battery specifically sized to their unit.

Pros & Cons

Pros

• High 10000 mAh capacity that noticeably extends playback time versus standard cells.
• Internal protection circuitry and extensive testing for reliable, safer use over many cycles.
• Direct compatibility with PartyBox Stage 320 and Xtreme 4 for a clean replacement.
• 12-month warranty and vendor support if questions about fit or performance arise.

Cons

• Requires a Torx T20 screwdriver for installation, which is not included, so some users will need to supply tools.
• Limited to the specified speaker models; not a universal battery for other devices.

Specifications

Brand	Sicimly
Model fit	PartyBox Stage 320, Xtreme 4
Capacity	10000 mAh / 74 Wh
Cell ID	PN FG4CELL21700H (3500 mAh cell spec referenced)
Chemistry	Rechargeable Lithium-ion
Warranty	12 months

Our Verdict

The Sicimly replacement for the JBL Battery 400 is a practical, value-minded choice for Stage 320 and Xtreme 4 owners who prioritize long run time and battery longevity. With high capacity, built-in protection, and a one-year warranty, it restores portable performance reliably; just be prepared to use a Torx T20 screwdriver for installation.

Frequently Asked Questions

Will this battery work in both PartyBox Stage 320 and Xtreme 4?
Yes, the pack is specified as fully compatible with PartyBox Stage 320 and Xtreme 4 portable speakers.

How long will the battery last on a single charge?
The pack is rated up to about 19 hours of playback per battery under typical conditions, thanks to its 10000 mAh / 74 Wh capacity.

Do I need any tools to replace the battery?
Yes, installation requires a Torx T20 screwdriver to remove screws and fit the battery; a screwdriver is not included.