Isn’t the Opus BT-C3100 the unit/model that has the pain in the A$$ fan noise failure issue? if so I would that this deserves to the added to the pro and con list?
And also how to they compare on price? It might be possible to buy two of one type over only one of the other? that might help address charge/capacity runtime issues?
No worries. I appreciate that you both were trying to help me with my question.
Did my Charge Test photos in post # 61 not convinced you yet?
Hi!
This is an old tread but here is my 2 cents.
I also get higher capacity ratings on both my Opus bt-3100 and my Liitokala lii-500. I have a project going to rescue some cells from dead laptop batteries and get some mesurements that are higher than their original capacity. (And almost all are higher than expected)
I use the “test” program on the opus that charges-discharges (and mesure this)-charge to 4,2V again.
The Lii-500 I use the “NOR TEST” that charges-discharges (and mesure this)- end (so it does not charge the battery back up.
Both mesures the discharge from 4,20-2,80V at a discharge of 0,5A.
When I get a cuple of cells that are 3-4 years old from defect laptop battery and have slightly higher (mesured on lii/opus) than original something is a bit off.
I will do more testing (have 4 lii 500, 2 Opus and 2 imax B6) to find the most realistic number. The B6 only discharge from 4,2-3,0V but I think the numbers I get from this is closer to reality.
Do any of you have a good thumb rule of what to take of the test numbers on the chargers to get the most realistic capacity?
Is 100-150mV around the right amount to discount from the capacity testing?
If I do remember correctly, HKJ pointed out that the way the Opus BT-C3100 consumes power (high current bursts) was probably the cause of the inaccuracy of its measurements, due to the fact that its power supply can't cope with these quite high input current demands without its Vin crumbling. Check this graph:
Has anyone tried to feed it with a proper 12V 10+A PSU, in order to see how it fares?
Cheers ^:)
I have an Opus and I’m feeding it 5A. I also have a Li-500 and an Accucell-6 hobby charger. They all give me different results but are probably within 10% of one another. Repeat tests on the same charger is more in the 2-5% difference, sometimes better.
The internal resistance measurement on my Li-500 is useless. On the Opus it’s pretty erratic but seems to at least be in some kind of ballpark.
Looking for a good charger that gives capacity reading and found this thread/argument. This gyzmo2002 dude is an arrogant tool to fight over a battery charger the way he did in this thread. :person_facepalming:
Interesting observation SSV…… 
Go with the Lii 500…. the OPUS does give “optimistic” discharge capacity readings. I have both & the Lii 500 is my go to charger for capacity measurement.
It is a bit cheaper also. 
Thanks man. Does it take hours to get the measurement, or can you insert and get it in a reasonable amount of time?
The Zanflare C4 should probably be thrown into the decision given the good review by HKJ.
Your welcome. It takes a while, but no longer than the OPUS.
I’ll check it out. Thank you sir!
the lii 500 at its maximum discharge current will take twice as time as the C3100. You have 500mA max discharge vs 1000mA discharge. So yes C3100 will discharge your batteries in half of the time if needed.
Discharging at the same current should obviously lead in the same discacharge time. And yes discharghing at 500mA a 3000mAh battery will take you about 6 hours (a bit less in reality since full capacity is less).
So at 1A with the Opus you will save 3 hours theoretically
An additional point: Storage charge-
On the bottom of the Opus main board after taking off the bottom (4 screws) is a switch: 4.2v/4.35v/3.7v. I cut a small hole so I could access it with a small rod. Tried out the 3.7v and it works! Now I have a charger that I can easily use to put cells in storage.
They do have to be below that voltage and be charged up.
Not sure any other non-hobby charge has this capability. If it has LiFe charging you can use that to get “close enough”.
Pretty sure that “3.7V” C3100 mainboard switch setting was intended for LiFePO4 charging, flydiver. 
I may end up assembling a fully current and voltage adjustable custom battery charger someday, there are plenty of parts and modules available to make it good, and a lot of handwork to be done if I aim for it to look at least minimally user friendly. 
Maybe it would be better not making it user friendly and equip it with electroshock safety measures against careless potential users (LoL!). 
Cheers ^:)
I think you may be right, but it works fine to create storage charge for Li-on. Tried it a number of times now and it seems to be reliable. Lots of people want a storage function in a 4-bay multi-charger. This is the only one I know of that can do it easily once you create the access hole. :+1:
I also tried it for LiFePO4 and that also worked a treat. 
I am using a Lite-on 12V/5.5A SMPS which was recommended by Dr. Gauss.
It has worked flawlessly with NO Stoppages during discharge cycle and MORE accurate capacity results.
I am also using a top tier Delta fan which also helps.
oh,yes,This is for my OPUS BT-C3100 2.2V
I average ~1% to 2% high. Never more than 3% high. Many times LESS than 1%.
This is in comparison to HKJ. My tests are also discharged at 1Amp
These were tested brand new. VTC6. HKJ got 2976mAh @ 1Amp
My 4 slot median was 3015mAh which is 1.29% higher than HKJ. I have some tests where I was less than 0.03% from HKJ. I will find them!
Here is One of my closest to HKJ.
HKJ 30Q= 2884mAh- My 4 slot median is 2905mAh which is ONLY 0.0072% higher than HKJ! :+1: