Someone else upgraded theirs by adding a fan to the base and supporting the back of the charger with 2 long screws. I think that’s a much better solution and also gives good visibility of the screen at a glance. The bigger fan is going to run with much greater efficiency and be close to silent!
Got my charger today. Just put in 4 shitfire cell to test out their capacity. I put it DISCHARGE mode, selected 1a. 2 of the batteries start discharging but the other 2 start flashing 500mA instead of 1a. They do have protection circuits. I instead changed the discharge current to 200ma but still the same thing happens, reverts to flashing 500mA. Have tried just the two batteries alone, same thing.
Is it likely the protection circuit or something? The other two seem to be fine with the same circuits.
Did you try the batteries that started to discharge in the bays that the other batteries would not discharge?
Also consider:
- do the cells in question work correctly in 1amp+ lights?
- are the cells in question charged?
- do the protection circuits need a “reset”?
Tried charging 4 AA xxx eneloops, they came off 1,425-1,435 not really satisfied with that.
That voltage is the usual figure out of the charger in my C9000 at “done” (1.44v to 1.48v). It will settle eventually to 1.3+
Can’t say for certain if they work in 1a lights.
The cells were at 3.7v~
Don’t know what reset the circuit means.
I did lower the discharge current down to 200mA and it was still doing funnies. I also reversed the slots and the batteries and they cells were still having issues in the other slots. Doesn’t seem to be the slot it must be something with the battery itself.
I’m gonna have to ditch the supplied travel adapter (EU>AU). It’s making crackling sounds when moved about. Oh and I also get a little spark shoot out when I plug the power into the charge itself. Scary!
Just started using the opus charger and there are a few quirks when using discharge mode and quick test mode.
I placed an old laptop and xxxxfire cell and charged both. After both cells where fully charged I set the discharge to 1A. The discharge test continued for 32 minutes before stopping. But when the discharge test had stopped one cell read 3.84v, the other 3.62v :~ Why would the discharge stop at only 3.8v I wonder when the manual states that discharge mode discharges to 2.8v?
Cell resistance is also widely inaccurate. One cell read 132 milliohms, I repeated the test and the same cell in the same slot read 431 milliohms 
Anyone else have similar issues?
You cannot measure what voltage the discharge mode stops at. What you measure it what voltage the battery recovers to.
In this curve I discharges down to 2.5 volt, but the battery recovers to about 3.3 volt very fast when I stop the discharge.
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Try pressing the slider against the battery, while it is measuring ohms. Contact resistance is a big problems when measuring Ri.
That seems unlikely since the discharge capacity read 414mah on the laptop cell and 326mah on the crapfire. Although the crapfire’s capacity may actually be that low :p. (remember these are both 18650 cells, if the tested capacity is true I guess it’s time they got the chuck). Is it possible that old cells with high IR will actually jump that high in voltage after being discharged to 2.8v?
Yes, you also mentioned this in your review. How would opus or any manufacture/designer be able to rectify this problem? It would seem that this is an important issue since increased resistance will result in less efficiency and more heat created at points of contact. Or would the gain in efficiency be only negligent?
Higher Ri means larger voltage jump.
Yes, you also mentioned this in your review. How would opus or any manufacture/designer be able to rectify this problem? It would seem that this is an important issue since increased resistance will result in less efficiency and more heat created at points of contact. Or would the gain in efficiency be only negligent?
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A sharp point with fairly high pressure is one way to reduce connection resistance.
Another possiblity is to use two separate connections, then connection resistance can be ignored.
Thanks HJK 
That clears up a lot of issues. I will test the discharge mode with a new NCRB
and hopefully the test results will display a relatively correct reading.
I don’t have fancy testing charts, but I find that this does not charge my various li-on 18650 or rcr123 or nimh aa as well as the i4. Those are the only cells I have tested. It refused to charge my sanyo 2700 and it under-charges my li-on cells, but I do very much like the discharge function that seems to work properly. I find the fan to be ridiculously loud and the ui is manageable.
Hi guys, this charger lacks reverse polarity protection afaik. What would happen if you put cells in a wrong way?
BTW today i received my unit, looking good for now, but i don’t understand why the charging current at some times was 750ma instead of 1000ma?
I noticed mine is a bit funny too. I just put 4 Samsung ICR 4.3 on Charge Test. 3 of them started and 1 just sat there doing nothing. Had to manually put it back in and restart. I also had 2 other batteries terminate at an indicated 4.15-4.16v and say FULL. Put them back in after an hour and they went up to 4.19/4.20.
Dazed I think the current tapers off towards the end of the cycle as indicated in HKJ’s graphs. As it approaches 4.20v the current is reduced. And no need to ask same questions in two threads!
There is need, when you dont get answer and you are a bit in panic 
When the voltage of the cell reaches 4.2V, after a while the current will gradually decrease down to about 1/10th of the rate chosen.
While the LCD display of the charger shows it terminated at 4.2V, the cell almost always goes back to the natural voltage of that specific cell, usually in the range of 4.14v to 4.19V, and in my experience, the most common is about 4.17V after a while.
I’d put a (slow) charge on those cells and try the discharge again. They probably have terrible voltage sag, a full charge will help a little with that. Based on what others have said you can probably expect relatively early termination if they are that bad.
Good demonstration of this.
A question a bit at an angle to the thread. What would be the best "hobby" charger to replace the Opus with better results and maybe more features? Assume that a power supply will be available.