Regarding cooling and chargers with discharge/capacity test…
It’s good that the Opus BT-C3100 has a cooling fan, although it does get noisy.
The Vapcell S4+ and the Liitokala Lii-600 (both of which do not sport any built-in fans) will get quite hot when doing discharge/capacity test (the onboard temperature sensor display will usually get into the mid to high 50 degrees Celsius) when I do a discharge test at 500mA discharge (4 batteries at the same time) — and I live in a warm temperature country whole year around (average is around 30+ degrees Celsius, maybe getting to 25 degrees Celsius room temperature during early dawn time in the cooler month (yup, just probably 1 month of “somewhat cool”). Anyway, I bought some USB-powered fans to blow at the chargers when doing discharge testing on those 2 chargers.
Many other analyzing chargers don’t have fans, eg. the Xtar VC8, VC4S also don’t have fans, but have low discharge current (300mA).
The Xtar Dragon VP4 Plus maxes at 500mA discharge current (but the physical unit is much bigger, so it can probably dissipate heat a bit better even without cooling fan).
So, aside from the Opus BT-C3100, the only other unit that has built-in fans for discharge testing might be the SkyRC MC3000 (v1 has 1 fan; v2 has 2 fans).
Although there are likely other analyzing chargers with fans that I’m not aware of.
~
some other note:
I believe the Opus BT-C3100 cooling fan may turn on depending on the ambient temperature, even though the charger is not in use (but plugged in to power).
I’ve experienced a few times that the Opus BT-C3100 built-in cooling fan automatically turning ON (the unit is plugged in to power), even when there is no battery inside any of the slots, probably due to the warm ambient temperatuer. I wonder at what temperature it does this though…
Hm, don´t have the C3100 plugged in if I don´t use it.
I´m also a bit worried about the small fan because it reminds me of some old videocards with similar fans or chipset-fans of mainboards. These ones often fail because of cheap (ball/sleeve?)bearings. And if you don´t notice it the videocard failed. The difference between the C3100 and the other fans is, the other fans work mostly on highest speed and the C3100 use lower rpm or turn it off sometimes.
Too bad that the C3100 have no USB-output, else I would combine it with an USB-fan
A big difference here is you can both see and hear if the fan is functioning. For a couple years I’d just take it out, lube it, and put it back. It was good for ~ 6 months that way. There’s a thread in BLF somewhere about a superior replacement. I finally did that and it’s been fine since, over 2 years. Still whines, when it turns on, but I point an external fan at it 90% of the time.
If the fan fails, you don’t burn out anything. Your batteries will just get warmer……kind of like the ones without a fan.
I agee, a USB output could be handy for a fan. I’m using one but it’s plugged into an external USB output.
If you have an old pc desktop psu you can convert it to put out 12v’s and 5v’s from the rails. I wired it up with with a 5.5 x 2.1 mm jack to power my Opus and the fan I took out of the pc. With the fan under the Opus it’s internal fan never comes on.
Thanks for the Info. Maybe I have to place it near an PC or use a Powerbank with an external fan . I think I have also some active USB-hubs which I could use.
Yeah, in my old PCs the CPU-fan and the PSU-fan were also noisy, so the videocard-fan was not so clear to hear. My C3100 isn´t old, I use it mostly for NiMH, mabe I never get the fan speed to the maximum.
I like my C3100, hope it will have a long life
Or maybe Opus will someday bring a new model with similar specs (and without fan)
. I think I have also some active USB-hubs which I could use.