What fans. More information. Part number or how much current the fans use.
What coin cell. More information. Coin cells hold very little power. They might not last very long.
What LED. More information.
How long should the battery last?
It looks like you need to "boost" the 1.5 volts up to 3.0 volts.
Hello everyone, the fans are mighty mini fans by sunon. The led is just to light up (blue) will 1.5 v power 3 fans? How do i boost power only using 1 small coin cell that is only 5mm
Basically you don't, as you have very little power available to play with - by far the easiest option would be simply to use two cells in series to power the fans. This will have the added bonus of powering them for considerably more than twice as long (as there's no waste), which probably still won't be very long anyway.
The Sunon data sheet has 36 (!!!) different part numbers on it, spanning 9 different sets of operating conditions and sizes. The required current ranges from 36 mA to 97 mA.
A lithium coin cell in your size has a standard discharge current of 0.1 mA. At a minimum you need *360 times* more than that. Even if you could extract 100% of the energy (30 mAh) at a current you can use (and you can not), it would run the smallest fan for less than one hour.
The only silver-oxide cell in your size range is a pair of SR68's, with a max capacity of 26 mAh. IF you could extract 100% of the that energy (and you can not), it would run the smallest fan for less than 45 minutes. In the real world that reduces to approx. 15 minutes.
Just for the 3 fans we need 100 to 300ma.
The Panasonic Lithium 3032 is not rated for more than 2mA. The internal resistance is too high to run one fan.