Quoting too often leads to this pyramiding effect.
From HKJ”s review:
OPUS BT-3100 v2:
Testing with 2500 volt succeeded, but 5000 volt between mains and low volt side on the power supply failed. This means this power supply is only safe for 110VAC, not for 230VAC (This is the US supply, the EU supply passed the 5000V test in the first review).
Conclusion
The charger has been improved with the updated software, but many of the problematic areas are stil present:
The user interface is fairly easy to use, but it may take a some time to learn what the different modes does.
The high current peak from the power supply is not good for the power supply and makes the charger show wrong readings.
Generally the peak charge and discharge current for LiIon are a bit high, especially on the outer slots.
The resistance measurement has limited use, not only due to contact resistance, with NiMH the precision is generally low.
I would have preferred constant current, instead of the pulsing.
The NiMH termination has changed, but it is a bit slow to terminate now (It does definitely fill the cells).
LiIon charging now works on all slots. The NiMH charging is probably not as good as in the first version, because the -dv/dt is rather slow to terminate
The analyzing function makes the charger very useful for anybody that wants to know something about the state of their LiIon cell.
The charger is not perfect, far from it, but as long as the problematic areas are know, the charger is a very useful tool
Liitokala Engineer Lii-500:
Testing the EU mains transformer with 2500 volt and 5000 volt between mains and low volt side, did not show any safety problems.
Conclusion
I like the user interface, put a couple of batteries in and select mode/current with the respective buttons. As long as the number keys are not touched the selection is for all slots (Showing all slot numbers would have been nice).
The charger is very good at charging LiIon, but stops a bit early on NiMH.
The fast test works fine on LiIon, but with NiMH it shows too much capacity (the full test looks more correct).
As usual I am not impressed with the resistance function.
The usb output has very low noise, but need multiple cells to work well with 1A load.
The final result must be that it is a good charger with a useful analyze function.
I have both & prefer the Liitokala UI & I think it charges a little faster when charging 4 x 18650 cells than The Opus, although that could just be me. (the Liitokala is also a bit cheaper in the UK than the Opus)
Thank you. I’m not familiar with this forum. Only the last quoted should be displayed. Not all… It is weird on my iPhone 6+, a lot of scrolling.
Next time, I will try to erase some of them.
Opus BT 3100 v2.2
Although it gives a higher capacity measurement, this is a great charger. I like more my Opus than my Nitecore D4. If I would not have the MC3000, it would still be my daily charger.
For the Liitokala, I don’t have it so I cannot give my opinion.
I also have a Nitecore D4 as well as the Opus & Liitokala.
The D4 is fine as a basic charger, just a little slow when charging multiple cells which is not a problem really.
Of the 3 chargers the Liitokala is my favourite.
In my post above wherein I quoted a 2.5v cut-out voltage, it was done with the iCharger, not the Opus, and the cell used was a Panasonic NCR18650PF. as shown in the link.
With Opus you can charge up to 4.35V (but you have to open it to get to the switch). You have the refresh program for NiMh batteries, you can charge up to 2000mAh on bay 1 and 4 with only two batteries. On the negative side, you have the noisy fan.
So I have two Opus BT C3100 V2.2 and two Lii 500 chargers. If I need to test or charge in the night, I use Lii 500, on the day Opus.
go for the Opus, its voltage are spot on, on my 2 DMMs my Liitokala 500 overcharges to 4.22V
and since this question has been asked many times, (it was something i wondered myself for a long time, until I bought both), i will paste here what I already written on 12/21/2015 - 07:24 in the Lii500 review topic Test/Review of Charger LiitoKala Engineer Lii-500 - #64 by TheBo
QUOTE: 1) The Opus uses pulse charging (HKJ would prefer it didn’t) and that the LiitoKala slightly undercharges NiMHs.” (quoting like this as quote button on OP is missing since site upgrade).
I saw a link posted some time ago (by tatasal maybe?) about tests showing that pulse charging is not an issue. I couldn’t find the link though. Has this changed?
“go for the Opus, its voltage are spot on, on my 2 DMMs my Liitokala 500 overcharges to 4.22V”.
Accepted charging voltage for 4.2v cells is +/- .05v so 4.22v is absolutely fine.
Immediately off the Lii 500 my DMM (Amprobe) shows cells at 4.19v.
“3100 has a more precise Voltmeter in my opinion and chargin is always Spot on I always found batteries at about 4.17-4.19V even after 30min pulled out of the charger”
Surely for the voltage to be up to 4.19v 30 minutes after charging dosen”t that show that the Opus is also charging over 4.20v ?
Not arguing just curious ?
At the end of the day I have both chargers & they are both fine chargers IMO I just prefer the Liitokala.
I own both chargers. OPUS is much “friendlier” for day to day usage.
Curious in what way ?
If you mean friendlier to the cells then the D4 is even friendlier as it only charges to about 4.18v in my experience.
I demonstrated that Opus provides a higher measure regarding the capacity because you affirmed the opposite in your first post and this is not the first time. All I ask you is not to make this statement anymore because it is false and this will induce member wrong.
If you need some help with the MC3000, you have my mail. An advice, don’t bother you with the dummy mode, go straight in advanced mode and you will learn a lot about parameters to charge batteries.
Here are the results of Discharge Capacities of my Opus BT-C3100 v2.1 and v2.2:
Cells used: Brand-new Samsung 30Q flat-top, brand-new Sanyo UR14500P 840mah and a slightly-used Panasonic NCR18650B 3400mah
Charger used to charge the Sanyo 14500 is the Opus itself.
18650 cells were charge at 1A, 14500 was charge at 700ma. Straight discharge mode was used in the two Opus chargers.
The photos below will show that the Opus does not read high as you believe it does, and is just as accurate as the MC3000, discharge-capacity wise:
The O ma pic just shows that discharging has stopped:
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You said you got 3252mah on your MC3000, well I got 3254mah from my Opus v2.2 (not bad at 2mah difference huh)
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I can’t seem to straighten up the pics, can somebody please do it for me? Thanks
Do a charge test. Nothing prove me with your test that your battery was full at the beginning. I could take one at 4.10 and do a discharge to have an accurate result as the one you are. On a charge test, the charger will charge to full, discharge to 2.80 and charge again.
Edit: At the end, I need to see charge test on your display.
I have nothing to gain if I purposely ‘undercharge’ as you maliciously suspect it to be. The cells were charged full, I’ll be crazy not to and just ‘approximate’ it to get the discharge capacities?
It’s now just past midnight…goodnight!
It is the only way for me to see that your batterie were full at the beginning.
Goodnight, we are 11:50am in Montreal.
@Tatassal
I have think to that again. All my tests were done on a charge test. (C>D>C) and yours on a discharge only. I think there is a possibility of another “flaw” with the Opus.
I never did a test only with a discharge only to 2.80v to test it. What I think with your results is they could be different between these two test. An accurate charger must give the same results like the MC3000 does.
Could you try a discharge test as I asked before with the same cell you did it? I am 99.9% sure that your results will be higher than the discharge only you did above.
I can’t do this test for now, only in the next weekend.
@members
For the others testers who have the Opus BT3100 v2.2 or the Liitokala and want to try it, it would be useful to see your results. The Liitokala could be more accurate than the Opus to measure cells capacity.
I don’t do the ‘test’ mode since it takes a very long time to finish it without a break, and, call it a flaw or whatever, but the Opus, and I remember it now as I have not used the ‘test’ mode’ because of it, I get confused with the figures shown. IIRC, the numbers shown after the Discharge portion are actually the Charge numbers (that is why you are seeing a higher reading), and I think you have to wait for the last numbers to show to know the discharge numbers, and that is after the second Charge portion.
I have pointed this out the to this charger’s designer. I have made an example of the simplicity of my Maha C9000 that clearly shows ‘available capacity’ after a Test session.
This is the reason why I use the ‘Discharge’ mode only to get the capacity for I will be certain the numbers shown are surely the discharge capacity, and I can take a break between modes, or give the cell a longer break, etc.
If you have time, take the Discharge test and compare it to your MC3000, and I’m sure you will see a much closer result.
At 1A rate, my opus showed 3,450mAh after discharging a set of Sanyo GA down to 2.7V, and the same set of batteries in the MC3000 with discharge current reduction (similar to CC/CV but for discharge) of 50mA and down to 2.5V I only got 3,350mAh. But the numbers from the MC3000 were actually closer to various results from members with sophisticated testing equipment.
Maybe this doesn’t happen with every unit, But at less than 5% variation I don’t think it is an issue at all, if one isn’t looking for the ultimate accuracy.
The opus is actually much friendlier to use for basic tasks, doesn’t require too many button presses to get it working.