how to run a cpu fan on batteries?

Pardon my ignorance... I have no doubt this is a simple question, and I wish I knew more about electronics so I didn't have to ask it!

I need to run an old CPU fan on batteries.

On the back of the fan it reads: DC12v 0.24A -S43V

Since I need 12v, would it be as simple as running 8 x 1.5 batteries in series?

If that is the case, would it matter if they were AA, AAA, C, or D batteries?

Thanks for your help!

Walter

thatguywhojuggles said:

Pardon my ignorance... I have no doubt this is a simple question, and I wish I knew more about electronics so I didn't have to ask it!

I need to run an old CPU fan on batteries.

On the back of the fan it reads: DC12v 0.24A -S43V

Since I need 12v, would it be as simple as running 8 x 1.5 batteries in series?

If that is the case, would it matter if they were AA, AAA, C, or D batteries?

Thanks for your help!

Walter

Click to expand...

No matter battery types. All you need is a 12V DC supply. It might work even at low voltages.

So I might be able to run it on a 9 volt battery?

If the 9 volt wasn't enough, I could also run a 9 volt and 2 1.5 volts?

Thanks
Walter

Sure! 9v pp3 won't last long. 12V 250mA X'former with bridge is another choice.

8x1.5V batteries will be fine providing it will work down to 10V (which it should do).

AAA, AA, C or D cells will do, it will just last much longer when run off larger cells.

The size of a battery determines how long it lasts to drive a load (your fan).
Go to the website of a battery manufacturer like Energizer and click on Technical Info to see the datasheet for every battery they sell:
1) A little 9V alkaline battery can supply 0.24A for only half an hour when its voltage will be less than 7V. In 1.5 hours its voltage will be less than 6V.
2) Eight little AAA alkaline cells in series make 12V. They can supply 0.24A for 1 hour when the voltage will be 9.6V and for 2.5 hours when the voltage will be 8V.
3) Eight AA alkaline cells in series make 12V. They can supply 0.24A for 3.5 hours when the voltage will be 9.6V and for 7 hours when the voltage will be 8V.

You can look up how long C and D cells will last yourself.
I would use rechargeable Ni-MH cells.

Thanks for the responses, guys. I just got back from Radio Shack with everything I needed and now have the fan running smoothly.

Thanks again.

Walter

And no one mentioned a switch mode power supply or microcontroller to get the apsolute maximum life out of the the batteries?
Are you guys loosing your touch?

forumlicker came close =) I'd use a 9pack of NiMH rechargeable, 2000ma AA's will last you close to 10 hours. Cheap RC car batteries (labeled 12V) and a charger might work better do, they use C and sometimes D cell Nicads.

Will the fan run off a car battery as well?

I have a pc fan that i need to install to help cool and cooler radio that i'm building.

character79 said:

Will the fan run off a car battery as well?

I have a pc fan that i need to install to help cool and cooler radio that i'm building.

Click to expand...

Yes, as long as it is a 12 volt fan it will run fine off a car battery.

Ron