Here are the results of my tests of the last few days regarding 2 issues reported about the MuseLuxe :
- Short battery life while playing audio
- Short standby time when the device is OFF after a few hours it does not wake up
Executive summary
in a nutshell the battery capacity is not good. For backers who bought the Luxe before February 4th 2022 I admit that the specification advertised was wrong about the battery capacity thus you can if you wish return the product for a full refund (I will also pay for the shipment return) If you wish to do that please send me a message.
There is also a tutorial at the end to guide you to replace the battery.
Analysis and root cause :
1. Short battery life while playing audio
I ran a discharge test while streaming an internet Radio using SqueezeLite and I got a playing time of about 4h15mn.
The battery management chipset (BMS) is charging to 4.16v and cut-off is at 3v. The battery capacity is quite low as I tested some discharge cycles at about 1500mAh, the battery is labeled with 1200mAh. Also notice that the value of the ADC is quite unstable, to me this is due the rather low capacity of the battery that when under discharge has a voltage drop, as the discharge changes quickly tension changes too.
| ADC reads | Vbat | factor |
|---|---|---|
| 2416 | 4.09 | 590.71 |
| 2407 | 4.04 | 595.79 |
| 2331 | 4.01 | 581.30 |
| 2324 | 3.98 | 583.92 |
2. Short standby time when the device is OFF after a few hours it does not wake up
For short standby time, when the switch is in off position, the battery only lasts about 14h. So there is a current leak even when off. The root cause of this current leaks come from the BMS chipset bug that draws about 14mA in off position, but this alone can’t explain that the battery is empty after half a day, so the quality of the battery is still in question.
When I did my prototype this was not the case so I suspect that it is a problem with the batch of this chip that I have used for production even if it was bought from an official source. This combined with a small capacity battery leads to a standby time below industry expectations for bluetooth speakers.
The BMS was also tested for security features, and it behaves as expected protections of overcharge and under discharge is working as expected. The battery built-in protection is also working as expecting. So no security issues.
Conclusion
Yes the BMS chip is drawing current even when off, this with a shorter battery capacity than I expected leads to the 2 issues mentioned. Changing for a better battery quality will drastically improve performance of the Luxe.
Just as a matter of comparaison original battery vs 3500mah Battery:
- Playing time goes from 4h to 9h+
- Standby time goes from 14h to 60h+
here is a tutorial on how to change the battery
For all backers that bought the Luxe before February 2022 I admit that the specification advertised was wrong about the battery capacity thus you are eligible for a full refund (I will also pay for the shipment) For future buyers the specification will be changed so they will be informed of the performance to expect before buying.