When plugging in your Boombot REX, the optimal charger current is .5A. Some USB outputs will have more current than this. As long as the voltage does not exceed 4.2V, you will not cause damage to the battery, however the excess current has been known to over-ride a switch in the circuitry that tells the MPU that the battery is at full capacity.
One might think that the speaker is not fully charged when in fact after an hour, of charging on even .5A, your speaker will be fully charged. To test this, try hooking your speaker up to a lower current charging source such as the output of a laptop. Most laptops USB outputs are lower current. Under the lower current input, the LED indicator should show that the battery is fully charged indicated by a solid green LED.
If you still have doubt regarding the charging status of your device, the other ways you can validate it are:
- Battery indicator on iOS - When connected to Bluetooth, your iOS device will show the battery indicator in the upper right hand corner.
- Runtime testing - Conduct a runtime test and 70% volume and see how long the playback lasts. At 70% volume, you should get the specified 4-6 hour run-time.
If you still run into charging issues, please contact firstname.lastname@example.org