Thanks for your help bud, im just beginning in this field. I only need it to run for an hour for a presentation. The goal is to run it off a button cells. How can i make it last 8 hrs? maybe a joule thief and a capasitor. Or should i use a chip with rechargeable battery?By dry cells, Bill means alkaline type batteries such as AAA, AA, C, or D size.
How long do you want the fans to run on one set of batteries?
For example 2AA alkalines will run the three fans for about 2 hours.
Thank you so much for your replaying and knowledge. I have been on other forums and their replay was so discouraging and just plain wrong. Like ( can i use your coin cell to power my tractor) i know thats not possible but oh well to each their own. I know what im trying to accomplish can happen, i just need the right help. So when you said 6.72 / 0.2 = ~34 CR2032buttoncells does that mean 2 CR2032 BUTTON CELLSIf you need 8 hours of run time and each fan requires 0.28A at 3V, then you will need a battery that can supply 0.84A at 3V for 8 hours. So multiply your draw (0.84A) time the amount of run time you need (8 hours) and you come up with a requirement of 6.72Ah. Realistically you will need a little more. So look for batteries that can give you a bare minimum of 6.72Ah, plus some extra. A common CR2032 button cell is a 3V battery, but has about 200mAh capacity (will vary a little by brand, etc..). So to get your 6.72Ah you would need 6.72 / 0.2 = ~34 CR2032 button cells to get your required run time, in a perfect world.
I think he means 34 CR2032 button cells...Thank you so much for your replaying and knowledge. I have been on other forums and their replay was so discouraging and just plain wrong. Like ( can i use your coin cell to power my tractor) i know thats not possible but oh well to each their own. I know what im trying to accomplish can happen, i just need the right help. So when you said 6.72 / 0.2 = ~34 CR2032buttoncells does that mean 2 CR2032 BUTTON CELLS
Uh, no. ~34 CR2032 button cells means approximately thirty-four CR-2032 button cells.Thank you so much for your replaying and knowledge. I have been on other forums and their replay was so discouraging and just plain wrong. Like ( can i use your coin cell to power my tractor) i know thats not possible but oh well to each their own. I know what im trying to accomplish can happen, i just need the right help. So when you said 6.72 / 0.2 = ~34 CR2032buttoncells does that mean 2 CR2032 BUTTON CELLS
Depends on the fans, but probably not. If they are rated for 3 V, applying 9 V to them will probably not do them any favors.So can i use a 9v and not fry the fans?
Let’s consider that you’re thinking of wiring the fans in series. Your draw for all three would be 0.28 A and need 9V. A draw of 0.28A for 8 hours is 2.24Ah. Divide that by the capacity of a typical 9V battery (550mAh or 0.55 Ah). The result is 5 batteries in parallel.So can i use a 9v and not fry the fans?
None of those.What about using capasitors, joule thief, risistor or just a plain chip? With our technology this can be done right?
Uh, no one has figured out a way to get more energy out of something than it has in it.What about using capasitors, joule thief, risistor or just a plain chip? With our technology this can be done right?
Running them in series may not be a very good idea. That forces all of them to have the same current and depending on the exact characteristics of the fans as well as the air load seen by each of them, that may not result in proper operation.Let’s consider that you’re thinking of wiring the fans in series. Your draw for all three would be 0.28 A and need 9V. A draw of 0.28A for 8 hours is 2.24Ah. Divide that by the capacity of a typical 9V battery (550mAh or 0.55 Ah). The result is 5 batteries in parallel.
Someone check my calcs. I’ve already taken my sleeping pills.
The problems you face come down to having 3 fans with each fan being a 3 volt 0.28 amp fan. So with the 3 fans in parallel you need a source power of 3 volts at 0.84 amp. Now in the interest of allowing some overhead on a battery supply I would just consider calling it 3 volts at 1.0 amp. In theory a 3 volt 1.0 amp hour battery would run your fans for about 1 hour but the reality is that a 3 volt 1 amp hour battery is not likely to provide that max battery rating for an hour. You may, for example, get 0.250 amp for four hours but I doubt the maximum for 1 hour or 2 amps for a half hour.I need to power three 3v 0.28amp mini fans, do I use 3v batery or a 9v batery? I dont want to fry my fans.
by Jake Hertz
by Jake Hertz
by Jake Hertz
by Duane Benson