^
Thanks,Mine are 3mm X 12mm. I think Home depot has your size. I will get them if they do when my new batteries[sold the others] come in next week. First I will see if these 3mm X 12mm work.I would only be able to use 1 because of their size. 2 of your size seems better!
@ Peter J.
Just got some 6mm X 1mm Neodymium magnets on Ebay….3X the money but will get here 3X faster than coming from China! :+1:
Thanks for your help, I am sure they will work after posting your pictures.
Did you try just using 1 magnet?
Are you using 2 to make it even?
,thanks,
I use two. On plus and minus. I bought them 100 pieces. The price was very low - US $ 1.51. The price is really fun. 100 pcs!! The shipping cost was US $ 0.63.
I bought them here:
https://www.aliexpress.com/item/Cylinder-Rare-Earth-Mass-Neodymium-6mm-x-1mm-Magnet-100-Pcs-Mini-Small-Disc-Magnetic-Materials/32849096796.html
Yes, I saw that. Great deal. I just did not want to wait 2,3 4 weeks for it. I paid $7.64 including shipping for 100 pieces! I only need 10 at the most. I will have them next Wednesday or Thursday.
Judging from my own experience, the only way to keep the OPUS BT-C3100 from overheating and also from heating the batteries, is to stick a big ass fan under it, there is no other option. 
Here is mine abomination, works great so far! xD I also put a step down converter, so I can control the fan speed.
hmmm…….I’ve got an extra Corsair liquid CPU cooler around here somewhere………
Nice custom fan A_M_K. :+1:
Now you just need a better power supply so you do not have stoppages and Resets where you lose all data during discharge tests like me and many others had from the original power supply.
My 12V/5.5A/66W Liteon SMPS
/\ :+1: That is a nice fan set up A_M_K. Good job.
Yep WolfDog, the ‘LiteOn’ power supply was a great find by you; as well as a lifesaver for our chargers with the crappy power supplies!! :+1:
Mine is still going strong…… 
A job well done by you!
We have to give Professor Gauss some credit for suggesting it!
My Delta fan and Liteon power supply are still working like a charm,15 months later! :+1:
Yep…. your right, “Professor Gauss” had slipped my mind. . :+1:
SUCCESS! Thanks Petr J. :+1:
Those same magnets doing something incredible!!
So what resistor was used to get the 12V down to 5V?
Excuse me being clueless 
Heat protection no longer works, but it’s noisy.
^
Heat protection no longer works The Delta fan REDUCES the heat!!
Sure it is a little louder but that is well worth the results. I turn my off when i go to bed,sometimes I have left it on and slept w/ no issues!
Looks like you modified it a bit more by removing some material.
Here is mine,It protrudes by 1mm,that is how much more depth it has then stock fan.
lol you make your things louder, those things are already annoying loud
I am right now installing in my Oscilloscope, bench PSU and reflow oven more silent fans
Sure I loose some air flow
2% - 25%
but those things are a lot more silent, especially the decoupled mounting with fan build in silicone edges reduce noise a lot
Rigol DP811
69.7m³ at 33dBA
1.7W
M8-S3
59m³ 19dBA
0,96W yes 18% less air with 44% less power
.
Siglent SDS 1202X-E
DFM6025S
12V 0.11A
29.56m³, 24.64dBm, hey nice they give the power of noise not the usual dBA value
http://p.globalsources.com/IMAGES/PDT/SPEC/115/K1115909115.pdf
Noctua NF-A6x25 FLX
29,2m³, 19,3 dBA
.
T-962A
SanAce 40
0.11A 8000 RPM
33dBA, 13-15m³
Cooltek Silent Fan 4020
13,5 dBA, 4.000 U/min, 11,5 m³
Can you shave a mil or so off it with a belt sander to make it more fitty?
I tried that and ruined one,made the walls too thin.
It works FINE the way it is,been working great for 2 years! The slight protrusion is a NON ISSUE!
I am not making anything louder! The DELTA is a bit louder than stock. Big deal!
The benefits are:
1. NO more stoppages during discharge. The old SMPS and fan would give inaccurate reading because of this.
2.No more resets. ALL info was lost when transitioning form charge to discharge. It would reset and turn off,hence losing all info.Hours wasted!
3. More accurate discharge results, overall LESS heat on Opus because of more efficient CFM,Cubic feet per minute,ability to move air is SUPERIOR to stock fan. 
The problem is not really the fan its the thermal design of the charger,
usually you place the fan close to the hot parts, use proper sized heat sinks and also align the cooling fins efficient to the air flow
If done so a fan with like 30% of the CFM would cool it way better than stock fan
so as this has no heatsinks at least mount the fan to the side so the air flow gets over the whole board equally, not mainly to the right side of it
probably any cheapo stock aluminum heat sinks across the 4 chips would have helped far more than any fan with more CFM and pressure
compared to the SkyRC your fan is likely a lot more powerful but the rest of thermal design is not good
