Powering a 12v dc computer fan with batteries

Thread Starter

r_dawson12

Joined Jul 27, 2013
7
Hey guys, I'm thinking of doing a very basic project. I'd like to make a portable air conditioner using a 12v fan powered by 8 AA batteries. You may have seen them, it's essentially a computer fan that pulls air from the outside, into a container filled with ice, and then there is a vent of sorts that the cooler air is pushed out of. My questions is would something like this:

http://www.amazon.com/electronics/dp/B00CQKCXXE

Work for powering a fan along these lines:

Fan


Thanks in advance, and sorry if this is a stupid question...I'm pretty new to electronics :p
 
Last edited:

wayneh

Joined Sep 9, 2010
17,495
Yup, that'd work fine.

You might consider pre-cooling the incoming air with a swamp cooler, basically cooling it by evaporating water into it. It adds humidity, but since you're passing the air over ice anyway...

Perhaps just have it all oriented vertically so that incoming air passes over the water that has thawed off the ice.
 

Thread Starter

r_dawson12

Joined Jul 27, 2013
7
I'll be using out outside and I'd like to keep it rather compact and portable. My GF will use it at my softball games I'm sure and she just had shoulder surgery so she wont be able to carry much lol.
 

wayneh

Joined Sep 9, 2010
17,495
The fan spec said 10mA. A typical AA might be 2500mAh, so would run the fan for 250 hours! (Putting them in series does not add capacity, just voltage.)
 

odinhg

Joined Jul 22, 2009
65
On the webpage for the fan it says 10mA under specifications, but on the picture of it, it shows 100mA (0.1A). For me, 100mA sounds more realistic than 10mA.

In that case it would be what wayneh said, but divided by 10. That is 25 hours theoretically.
 
I look to use a 3 cell lithium battery typically used in RC cars. pretty cheap these days (Under $40 with a charger for a 5000mah probably), and will run your set-up much more cost effectively.

Battery: http://www.hobbyking.com/hobbyking/store/__9184__Turnigy_5000mAh_3S_20C_Lipo_Pack.html

Charger: http://www.hobbyking.com/hobbyking/store/__9184__Turnigy_5000mAh_3S_20C_Lipo_Pack.html

I have personally used this charger and battery, they work great. I power all my battery operated projects with RC lithiums. 3 cell batteries like these are great for 12V projects, 12.6V full, and about 10V when needing to be recharged.
 
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