USB fan with 18650 battery power bank - will it work?

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ArminVanBuuren

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If I buy this portable USB fan:

**broken link removed**

And connect a 5V power bank from 18650 battery:

**broken link removed**

Will it work?

I know it's quite crazy, but the bank states max. discharge 1 A, the fan takes 0.5 A. So with a 3000 mAh battery, could it even last for 6 hours?

Thanks
 

USB 2 supports up to 500mA with enumeration ( communication) otherwise only 100mA and USB 3 supports up to 900mA

However this cable supports 1000mA but you need a 1000mA source which is not provided. All they do is insert a diode to drop the charge voltage for LiPo which will lower your fan speed.

Get a proper power supply. or use a CPU fan with 100mA on 5V from USB.
 
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You do not know the current used by the fan. They recommend using a 1A transformer to power it.

A Lithium rechargeable battery has an average output voltage of 3.7V, not 5V. The power bank uses some battery power to work so for it to produce 5V at 500mA then it takes (500mA x 5V/3.7V plus maybe 50mA=) 726mA from the battery. IF the battery is actually 3000mAh then it will last for 3000/726= 4.1 hours.
 

Output: DC 5V,1000mA(Max) (from the power bank's specs)

Why is 1 A source not provided, then?
 

it is just a simple LiPo charger for an MP3 player battery. No battery included. No power source included, unless you provide 3.7V Lipo battery then you get 3.7V+/-.3V

This will not work.
 
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SunnySkyguy said:
it is just a simple LiPo charger for an MP3 player battery. No battery included. No power source included, unless you provide 3.7V Lipo battery then you get 3.7V+/-.3V

This will not work.
Click to expand...

Sure I would insert a battery :-DDDDDDDDDDDDDDDDDD But not Li-Pol, I would prefer Li-Ion (18650 4.2 ... 3.2 V)
 

Most of the 18650 cells I see are Lithion Ion Polymer.

The correct term is “Lithium-ion polymer” (Li-ion polymer or Li-polymer for short). Li-polymer can be built on many systems, such as Li-cobalt, NMC, Li-phosphate and Li-manganese. For this reason, Li-polymer is not considered a unique battery chemistry. Most Li-polymer packs for the consumer market are based on Li-cobalt.

It still wont work very well unless half speed is ok for you.
 
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SunnySkyguy said:
It still wont work very well unless half speed is ok for you.
Click to expand...
No, it will work perfectly because the Power Bank claims to produces an output that is 5V at up to 1A.
BUT it is cheap and is sold on E-bay so maybe they lie about it and it might be fake.
 

Audioguru said:
No, it will work perfectly because the Power Bank claims to produces an output that is 5V at up to 1A.
BUT it is cheap and is sold on E-bay so maybe they lie about it and it might be fake.
Click to expand...

I was also wondering, where he got the half speed from. If the device really produced 5V, it should work on full speed.

Do you know any similar devices that would provide portable supply (from batteries) for USB 5V? If this one might be fake?
 

Hi, I bought a power bank and a USB fan a while back. The fan was very similar to the one that you linked to, but from Menards. The power bank had 2.1 amp and 1.5 amp ports. When I plugged in the fan, it would start and stop. It didn't run at half speed. In my mind I think that the fan was pulling too much power and the power bank thought it might be a short, cut the power, and then tried it again.

On paper it does seem like it should work because 2.1 amps @ 5V is over 10 watts, and I have tested the fan using an AC adapter and even with converting the voltage it only used 6 watts. However, it didn't perform how I was hoping. I'm still looking for a way to get it to work.

Since then, I have seen other power banks with reviews that say that using a fan works great, but I don't know what type of fan. They do make smaller USB fans, and it might have been referring to that.

Were you able to try it? If so, did it work?
 

The trouble with buying cheap Chinese junk on ebay is that there are no valid detailed spec's and quality is absent. Maybe if you bought 10 of them you might find a few that work OK.
 

Audioguru said:
The trouble with buying cheap Chinese junk on ebay is that there are no valid detailed spec's and quality is absent. Maybe if you bought 10 of them you might find a few that work OK.
Click to expand...

That's why I went with one from Amazon...
 

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