Sick and tired of Opus. Is there a reliable, accurate and safe charger cheaper than MC3000?

CMU_84 · January 26, 2019, 4:43pm

@bushmaster Thanks for the feedback, really helps to confirm my decision.

Alexium · January 26, 2019, 4:48pm

Have you checked the voltage reading accuracy with a DMM?

bushmaster · January 26, 2019, 5:20pm

I have on several occasions. Always within a hundredth or two. Consistently charges my unprotected 18650s to 4.18. The only issue with it ( and this has been discussed ad infinitum in previous threads on BLF) is its insistence in analyzing button-top batteries as having high internal resistance and charging them at a slower rate when on auto. I don’t use button-tops that much so it doesn’t bother me and of course I can always kick the amperage up manually if I want.

Alexium · January 26, 2019, 5:22pm

The auto mode seems a gimmick anyway, unless you’re in a real hurry, IMO.

RobertB · January 27, 2019, 6:36pm

Alexium:

RobertB:

45C doesn’t sound like it’s over heating to me. Start worrying if it hits 80C.

It never did that before. This is a somewhat worn-out Sanyo cell, specced at 2000-ish mAh, some 1500 left in it. It could get slightly warm, 34-36 C, perhaps, but never hot. And the most bizarre is not the fact that it got hot but the circumstances. It was charging at 500 mA, the process was some 30 minutes in, it was nearing the switch from CC to CV. Voltage reading was something like 4.13 V. In fact, I think it might have switched to CV already but I’m not sure. Then I went out for ~50 minutes, and when I’m back it’s at 500 mA and 4.1 V, and the cell is hot. Clearly, it’s not normal for the voltage to go down during charging, the charger should have detected that as a suspicious behavior and stopped charging.

Maybe you got a dud charger, but maybe it’s time for a new battery. To be honest, after purchasing the Miboxer C8, I set my Opus for 3.7v, and use it only to discharge cells for long term storage. I drilled a hole in the bottom of the Opus for access to the switch.