Gearbest were very kind to send me this updated charger to review.
Much of the performance improvements have been covered already by HKJ, so I hope members find my review useful!
Opus BT-C3100 v2.1
Opus branded retail box, feels more like a product now:
Back of box with CE and FCC logos:
Contents include manual sheet, charger and 12V 3A PSU:
Back of charger, shown beside included Meic branded MN-A036-E190 adaptor:
It is a small detail, but I preferred the right angle plug on the adaptor that came with v1.0. There is also no power indicator on this adaptor.
Rear cooling fans, with v2.1 (above), v1.0 (below):
Underside (left v2.1, right v1.0):
PCB comparison (left v1, right v2.1). Has yellowed slightly from use in v1.0:
Most notable is the inclusion of a 1000uF capacitor to smooth input from PSU. Lower case molding now covers the fan, where before there was black tape. There is also some adhesive foam to help isolate vibration from the casing.
Some of the resistors are a light green colour, so might be from a different source.
v2.1 PCB (click for full size):
Other side:
Close examination of PCB showed many small solder flakes which can cause shorts. I used an anti-static brush to clear them. Here are some stuck to inductors:
On power up 2.1 is very briefly shown. Note the blueish tint to the backlight:
Also different, the screen is not as bright as v1.0, and I find it harder to read.
This is how it looks with no ambient light:
A travel adaptor was also included since the PSU has Euro plug connector. A little warning about these, they do not conform to BS 1363 standard.
Since I don't have any spare 3A supplies I removed the earth contact inside because it was uncomfortably close to the other terminals.
Display showed cells 0.03V higher than v1.0 and my DMM, which is within the stated ±0.03V tolerance.
I do wonder if this might cause the charger to terminate too early (I have an ML-102 that terminates at 4.16V). I will update with my findings.
Cell | DMM | v1.0 | v2.1 | ||||||
1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 | ||
Eneloop AA | 1.4 | 1.39 | 1.39 | 1.38 | 1.37 | 1.37 | 1.37 | 1.37 | |
Sanyo UR18650FM | 4.19 | 4.18 | 4.18 | 4.18 | 4.18 | 4.21 | 4.22 | 4.22 | 4.21 |
Warsun Protected 18650 | 4.13 | 4.13 | 4.13 | 4.13 | 4.12 | 4.15 | 4.16 | 4.16 | 4.16 |
I made a short video to demonstrate the improvement in fan noise:
Thanks for reading! ^_^