I replaced the fan after it went bad. I thought I was careful putting it back together, but now it is not working correctly. When I put a battery in to charge, the display freaks out, goes blank, flashes, then settles down and starts charging. When I put another battery in, the display freaks out again, goes back and forth from ‘null’ on some of the displays (whether they have batteries in them or not), then settles down and maybe a display might say “nu” or some other garbled mess. The displays also seem to be affected more when the springs are stretched back and forth on the slots.
If memory serves me those springs kinda float on the poles at the one end. If there is bad connection at the pole connection or the other end, it could explain the random issues you are seeing.
Tear it apart again and clean everything, got nothing to lose at the juncture.
Hmmm, following this thread, since I’m waiting for a new fan for one of my Opus BT3100 v2.2 chargers. If changing it can do that, maybe I can live with the noise from the old fan.
I am also thinking about just making a big box to sit the chargers on. Put some large, quiet, high flow fans under a screened top. Maybe open some more holes in the chargers, and go. Could be cheaper and quieter. Little fans can get pretty noisy.
In my case, I use a fan taken from a busted computer PSU, then drilled holes at the bottom of the case of the charger, then cut the wire with the connector from the original charger, solder it to the wire of the new fan. Now the fan functions automatically and as needed, just like the original fan. No need to take out the original fan. My fan sucks the air from in inside of the charger, fresh air is drawn from above the cells, passing through the four rails, cooling the inside of the charger and is finally sucked out of the charger. It’s been that way for almost to years and the cells and charger barely get warm, even at discharging 4x1A.
$3.29 same fan, just thicker.
You will need to dremel the case a small amount and the very corner/edge of the motherboard, no big deal.
It is still noisy just not as bad and it seems to hold up.
Another good solution is one of those cheap USB powered laptop base fans.
HTH
My charger over charge my 18650 to 4.3V (indicated on LCD and later verified with dmm) for the first time! I happened to place my mobile phone right under the charging station rack. Not sure if it was due to the radio interference from phone. I thought of replicating the problem again, but I afraid more damage to my batteries.
Did you find the problem krono? I took apart my D4 and the LCD wasn’t sitting in place correctly so it was a jumpy try and see if the LCD is in place? maybe the new fan is apply pressure in the wrong areas?
Using the control from the charger for an external fan is a good idea. I have looked at how the 4 wire fans work and was thinking about building something with a 12 VDC supply and some 4 wire control chips. With or without temp sensors. And looking into possible use of the internal control of the chargers. The post above from tatasal has already resolved that.
Just a 12 VDC supply and the internal controls from the charger is a nice simple solution.
I took a stock 2-wire 80mm computer fan. Took 4 of those coarse screws commonly used to attach them to the case and put them part way in. Put a little bit of foam ’padding” on top the screw to minimize vibration, and power it with a small 12v wall wart. I just put the whole charger on top and run them both at the same time.
FWIW, those little fans have crappy sleeve bearings, often poorly lubed to start. Before I ever even ran it I took it out and put some real good silicone grease in it. You want to get it BEFORE the bearing wears and gets sloppy. Results may not be as good doing this after it starts to get troublesome. It’s still whines a bit but that’s normal fan noise from the little high speed blades. It’s never gone bad in over a year of use. I was forewarned by this forum and obnoxious experience with other similar fans in the past.
