Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: 2 AA batteries instead of CR2033?

Learn more physics!

Most recent answer: 12/20/2015
Q:
I have a small LED "tea light" that runs on a CR2033 button battery at 3 volts. The battery only lasts about 100 hours. Can I hook up a pair of AA batteries (at 1.5 x 2 = 3 volts) in a double AA battery holder to this light, Gerry-rigged, instead of the button battery, to give it much longer run time before the battery needs changing. The lights have a timer which runs them 5 hours at the same hour every day. They sit in stone Japanese lanterns in the yard to give a lite appearance.
- John Sorensen (age 67)
Folsom, CA. USA
A:

Yes you can. Remember to connect the batteries serially, not in parallel. That is + electrode of one cell should be connected to - of the other, while remaining two electrodes should be connected to the circuitry.

Since you said that the system is outdoors: do your budget and the environment a favor and use solar power, so that you will not need to change the batteries in the foreseeable future. The easiest way is to buy some solar garden lights and connect your circuit in parallel to the batteries. It should be quite affordable.

Tunc


(published on 12/20/2015)

Follow-up on this answer.