Facts and Infos about the Opus BT-C3100 Charger

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Cherry67

Active member
Joined
May 13, 2018
Messages
497
Sorry, a second info i can give:
https://secondlifestorage.com/t-Kelvin-measurement-4-Wire-connection-Inner-Resistance
On the first page a little down, a detailed comparison between a B6AC IR Measurement and the same on the Opus, showing that even with wire mod the IR can be far ( 3 times ) off from a real value, especially on low IR.

Conclusion is, that the (two) contact resistances come into the same region as the Cell IR, plus they are unstable and not repeatable.

Update, re below Post :
Sorry, have not seen that.
 

Overmind

Active member
Joined
Jan 16, 2019
Messages
422
daromer said:
Dont put a fan om top over the cells. Cooling should be under the Opus or om the back

The objective was to trick the over-sensitive at room temperaturesenor.
The cells I put in cannot overheat because they are pre-tested before capacity measurement, so practically there is no OH danger.
 

friedpenguin

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Joined
Apr 1, 2019
Messages
27
I have what appears to be a dead C3400. Is there any way to revive it? I've tried a higher amperage 12v power supply to no avail. It started phasing out on the screen before going tits up and I read the bricks could be an issue so I went overkill with a 12v 8a but no display. Just the fan spins up.
 

theblackpawn

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Jul 31, 2019
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2
Thanks for the post. I really appreciated knowing what some of the options mean. Brand new to the field and the Opus BT-C3100 is my first charger.

Before I learned what "test" meant I threw a couple of (what I was told were new) samsung30Q in and let them charge (.5A) up to 4.2V and then switched to discharge (.2A), let them discharge until the Opus stopped the dischargeat 3.4V. All 4 batteries showed 2000+/- 10mah. I expect the 3000mAh the specifications are across their whole volatage but is there really 1/3 of the mAh under 3.4V or is charge then discharge not?

I'm using the charge test mode now to compare, I'm hoping to get better results :/

Any answers, thoughts,or tips?
 

barns

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Joined
Dec 23, 2018
Messages
29
rev0 said:
I did a bit of analysis of how the Opus works for those who are interested. Also have oscilloscope traces I took of the current waveforms, but I haven't processed/uploaded those: http://rev0.net/index.php?title=Opus

Images are dead

My opus fan mod:

image_znsbbq.jpg
 

cichy45

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Joined
Sep 10, 2020
Messages
4
Did any of you noticed issue, where Opus reads too LOW voltage? When charging with 200 mAh voltage @ Opus is what show my multimeter, when charging at 1000 mA, it can be 0.05-0.08V difference. Issue is not connected with Voltage Jumper since jumper sets to read voltage higher, not lower and my is disconnected as it should be.
 

bianchifan

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Joined
Jan 16, 2021
Messages
1
Just stumbled about this thread a week ago while looking for an alternative fan.
So..this thread is called: FACT & INFOS


FACT is: The linked Wire Mod is nonsense!
I own the BT-C3100 for roundabout 6y since I found it on Budgetlight or CPF or something else...
The spring is totally out of the game, no current flowing through!
The pins fixing the springs fit with the cover and are fixed itself with some silicone.
The current flows through the slider contacting the slide channel on the PCB.
Contact problems may occur over the time due to settled dust and other mud.
A clean job will do the trick for better resistance measurements.
Inaccurate (useless) IR (Internal Resistance) readings
The readings may not be the best precise but far away from "useless".
 

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Fabioxp79

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Jul 13, 2021
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Good morning sorry for this reply to a quite old discussion but I am owner of an Opus charger, I use occasionally to recharge my Ni-Mh batteries used in child toys and a series on eneloop for my camera external flash. I know this kind of charger have a lot of feature and I will search best practics to do a good job of charge (i.e. Discharging or test, refresh etc). My main concern is about fan noise. I know there are some suggested mods but I ask, an original replacement fan will be more silent maybe because of improvements design? If I don't wanto to do any fan mod because I use this charger occasionally, will be enough to silent a bit the fan to use a sylicon oil in spray? Thank you for any tips about my questions.
 

OffGridInTheCity

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Joined
Dec 15, 2018
Messages
1,657
My main concern is about fan noise. I know there are some suggested mods but I ask, an original replacement fan will be more silent maybe because of improvements design? If I don't wanto to do any fan mod because I use this charger occasionally, will be enough to silent a bit the fan to use a sylicon oil in spray? Thank you for any tips about my questions.
I've sprayed wd-40 on my OPUS fans - no difference. Maybe buy some fans and you might get some that are more silent than others... its likely a hit-or-miss kind of thing :)
 

floydR

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Aug 23, 2017
Messages
1,224
I have used silicone spray, and it does quiet the noise down for a while. I have also used an external fan on the bottom of my Opus 3400 (3100 board inside, different firmware?)connected to fan switch. But for the last 2000 cells just place the Opus's on top of a comuter fan sucking the air out of the Opus's, On my Opus that I have set up to test 26650 LiFePo4 cells I have the cells in cell holders . Cell holders-wires-Opus I notice that 90% of the heat is from the resistors. The fan makes noise from time to time bu no where near as often as the other Opus's.
later floyd
 
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