13500mAh Replacement Battery 400 for JBL PartyBox Stage 320 and Xtreme

Our review of the 13500mAh Replacement Battery 400 finds it best for owners of the JBL PartyBox Stage 320 or JBL Xtreme 4 who need a reliable, long-running spare battery. It excels at extending playtime with a high 13500mAh capacity and straightforward LED charging indicators, and it ships with a USB A to C cable for fast, convenient recharging. If the priority is simple swap-in replacement power that restores long listening sessions without complicated setup, this battery delivers that core promise well.

Key Features

• High capacity: The 13500mAh (99.9Wh) rating provides noticeably longer playback so users can run a speaker through extended events without frequent recharges.
• Fast charge ready: Included USB Type A to Type C cable lets you recharge from a portable power bank or wall charger quickly and is also compatible with the original battery charger.
• Visible charging status: The LED indicators clearly show progress with green for charging and red for fully charged, so you always know when the battery is ready.
• Simple replacement: The battery installs via the rear compartment on the PartyBox Stage 320 and by unscrewing the top cover on the Xtreme 4, making swaps straightforward for most users.
• Long runtime: Rated to deliver up to 18 hours of playtime per battery, allowing parties or long sessions to continue with minimal interruption.

Who It's For

This battery is ideal for people who already own a JBL PartyBox Stage 320 or JBL Xtreme 4 and want a high-capacity spare to extend playback during gatherings, outdoor use, or long work sessions. It suits DJs, event hosts, and anyone who values straightforward replacement and long runtime over wireless charging features.

Those who should look elsewhere include users whose speaker model is different from the two listed, and buyers seeking a battery with a smaller, exact OEM form factor; a few customers noted the size is bulkier than original cells, so check fit before purchasing if space is tight.

Pros & Cons

Pros

• Long-lasting 13500mAh capacity gives up to 18 hours of playtime per charge.
• Fast charging via included USB A to C cable and compatibility with original chargers.
• Clear LED indicators make charge status easy to monitor.
• Easy to replace in supported speaker models, restoring hours of use quickly.

Cons

• Size can be slightly larger or bulkier than the original battery, so fit may be mixed for some users.
• Only compatible with the PartyBox Stage 320 and Xtreme 4, not a universal speaker battery.

Specifications

Voltage	7.4V
Capacity	13500mAh / 99.9Wh
Compatible models	JBL PartyBox Stage 320; JBL Xtreme 4
Included cable	USB Type A to Type C charging cable
Indicators	LED: green charging, red fully charged
Support	12-month replacement exchange

Our Verdict

The 13500mAh Replacement Battery 400 is a practical, cost-effective way to restore long runtime to a PartyBox Stage 320 or Xtreme 4 without fuss. It offers reliable charge indicators, fast recharging with the included cable, and clearly targets users who need extended playback rather than a perfect OEM fit. Given the capacity and included support, it represents good value for owners who need dependable backup power.

Frequently Asked Questions

Will this battery work in any JBL speaker?
It is designed specifically for the PartyBox Stage 320 and Xtreme 4 and should not be used in other models without confirmation of compatibility.

How long does a full charge last?
Rated runtime is up to 18 hours per battery under typical use, which lets many users run long events or combine two batteries for extended sessions.

Does it come with a charger?
The package includes a USB Type A to Type C charging cable and is compatible with portable power banks and the original battery charger for the speaker.