Review: Opus BT-C3100 V2.1 (with teardown and video)

According to Henry Xu the voltage difference is within the tolerance of the charger (±0.03V). I miscalculated the difference by a decimal place. :zipper_mouth_face: It is easy to do when expecting 4.20V resting voltage after charging!

It is nice that the display is updating more often.

The problem is that 1000uf is a drop in the proverbial bucket compared to what is actually needed in a V1 or V2 charger. The thumbnail calcuation for the V2.0 version of the charger suggested 100,000uf at 16v would be required. The current is a little lower on the V2.1 charger, but the basic problem is the same. IF you are concerned just buy a larger AC adapter. You can get a 6-8 amp unit on eBay for under $15 in the US. I have a V2.0, and bought a 6 amp adapter.

Do you think your 6 amp adaptor works better than the 3amp it came with? Have you seen any difference in performance?

Yes, the charge capacity and the discharge capacity measurements are now only about 10% different. Given that the charging process is not 100%
efficient, that squares with reality reasonably well. The real question is can the AC adapter sustain the short term current requirements. The 3 amp
AC adapter suffered from substantial voltage sag because it could not.