Postbag #13: 99p VGA Fan, 5600mAh Banggood Power Bank

A couple of items of post from China

2 Pin 50mm DC 12V VGA Card Cooler Heatsinks Cool Fan SY

[JasonMasters]

Those "springy things" are for mounting the heat sink on a PCB. You mount the LED with the light showing through a hole in the PCB and mount the heat sink so that it's pressing against the rear of the LED, using holes in the PCB which those "springy thing" posts go through. Sometimes you lock them into place with a quarter-turn and sometimes it's automatic.

[iamdarkyoshi]

Julian, if those heatsinks are copper, try soldering the back of those 1w leds DIRECTLY to the heatsink. I did this with a soup can lid and it works fantastic. If you need more detail, i could post a video. Also, those spring clips would normally push into a graphics card's pcb, and the springs would provide the tension to hold the heatsink to the chip.

[j.lo.]

I once treated a small burning wound with a similar fan. Just tape the heatsink to the skin with a 9V Battery. 

[sourcedogDE]

Your fascination with power banks is... fascinating :P It must've rubbed off on me, as I'm currently fiddling around making a diy version with 18650 holders, and some soldered together charger/usb output modules. Thinking about adding an led display for voltage/amps and a combined step down/up module for a portable variable power supply while I'm at it.

[RicardoPenders]

Those springy thingies are meant to be pushed through the PCB and the springs will keep the right pressure on the heat sink... They are not meant to be used like you said in the video.

[NightWolfx]

Only thing i don;t like about the little VGA sinks is the fan life, however if you take the fan off to work on them, you can carefully put a drop of a good oil into the sleeve bearing on the fan ( unless you are luck and found cheap ones with ball bearings ) and you can make them last alot longer.

[JerryEricsson]

Got one of those 2 cell power banks after watching this video, dang thing failed me yesterday, went dead, well down to one dot, when I tried to charge would not connect. I tore it down and the USB in plug had seperated at the connection to the board. I tried to solder it back on but then it seperated at the plug.  Tore the board off and kept the cells.  Case may be used in some future project.  Not a lot goes to waste here in the Dakota's.  Must come from being raised on a farm back in the 50's.

[scivids]

How many watts of thermal capacity would those be able to take; they don't seem to have a lot of surface area?

[erlendse]

Not like my power-banks I have stepped on and used quite a lot.

I have never quite liked the auto-power-off function, so I prefer the "dumb" packs without micro-controller.

The fans looks good, but I would find a that small fan with that high speed annoying.

[jusb]

wonder if there is such a thing as thermally conductive epoxy? if so, would be handy!
, as for the cells, i wonder if they really are the proper capacity or if you were to open them up, you might see they contain a smaller cell and the rest filled with sand, or i have heard some are recycled worn out cells from old laptop supplies

[raykent]

Pardon me for being a bit "old school", but the way I'd measure the real-world capacity of a power bank is by fully charging it, connecting a resistor across the output and seeing how long it takes before it cuts out. I'm sure you don't need this, Julian, but maybe for others... A 5ohm resistor across a 5V supply will draw 1 amp. If it keeps going for 2 hours it has a capacity of 2 amp-hours at 5V. That resistor needs to be rated at at least 5 watts, but a bit of simple multiplication and waiting around longer let's you use almost any resistor you have lying around. I hate your videos, it's your fault that I still haven't done the washing-up because they're addictive! (in case of doubt, that's a big compliment, thanks)

[dorfschmidt]

After four weeks, I'm still waiting for my stuff from China.

[BMAK]

What is the best way to measure the output of a solar panel Julian. Do I just hook up a multimeter and see what it produces or is there a more forensic way of doing this?

[joshuasmith]

Never mind I got it working! For me I had to double-click to turn on the flashlight and long press to turn it off 👍🏼😊

[AntonBabiy]

From experience those fans die in a year. The bearings wear out and they start to wobble.

[FireSwordl]

I have IPC1 AA/AAA battery charger which can measure the mAh of NiCD and NiMH batteries. I hope such device exist for 3.7 Li batteries too...

[pcuser]

The ebay seller has 9 coolers sold in a hour. I like the idea. Bought 3 myself.
For the 10 watt leds.

[stanislavilchenko]

Hi Julian,
You can make just a simple discharger with a couple of resistors and Arduino. It is very simple and it can measure voltage and current per second. So, this would be more usefull power storage meter W*h instead of mA*h. I made it by myself and it is realy usefull for measuring real capacity of Li-ion batteries. If you need I can publish How-To of making such device.

[joshuasmith]

The flashlight on my power bank won't work? Any suggestions?

[CarlRecktenwaldJr]

How about a video on the DIY camera stand!!! Looks Neat...