Date: 2026-03-10

Bulletin version: 1.1

Applies to: SOWA Live 6, Live 12, Tour 6, FOH — all firmware versions

Audience: Distributors & service partners

Summary

All current SOWA speakers have a known quiescent current drain of approximately 1 mA while powered off. This is caused by the DC/DC converter remaining active in the off state. Over extended storage, this leads to measurable battery depletion that may not be accurately reflected by the battery management system (BMS).

The BMS is unable to reliably track such a low continuous drain, meaning the reported battery percentage may appear higher than the actual charge level. This can result in a speaker that appears healthy but is unable to power on, shuts down unexpectedly, or dies suddenly during use — particularly after a period of storage or shelf time.

Technical Details

• Quiescent drain: ~1 mA continuously while off
• Daily loss: ~24 mAh/day
• Battery capacity: 5,000 mAh (INR21700 5S1P, 18V 90 Wh)
• Expected depletion at 4 weeks: ~720 mAh (~14–16% of capacity)
• BMS may still report near 100% despite actual depletion
• Full discharge from storage alone: ~208 days (approx. 7 months)

Risk

A speaker that has been in storage may show a healthy battery percentage but fail to power on or shut down unexpectedly under load due to the BMS under-reporting the actual discharge. This is especially likely after 4+ weeks of storage, and has been observed in the field.

Customers receiving a speaker with a degraded battery may experience a dead unit on first use, leading to a poor unboxing experience and unnecessary support cases.

Recommended Actions

For distributors — before shipping any unit

1. Always charge to 100% before dispatch, regardless of the reported battery level.
2. Do not rely on the BMS percentage for units stored more than 2 weeks.
3. After charging, verify the unit powers on and operates normally before dispatch.
4. Track shelf time for all stock. Units stored longer than 4 weeks should be considered at risk and must be charged before shipping.
5. Rotate stock — ship older units first.
6. Consider a periodic top-up charge for any stock held longer than 4 weeks.

For customers — in the box / quick start

⚡ Charge your SOWA speaker before first use.

Even if the battery indicator shows a high charge level, we recommend a full charge before powering on for the first time.