Adafruit Micro-Lipo Charger Prod ID: 1904 Moderators: adafruit_support_bill, adafruit

[mfrye1399]

Hi there, Not sure if anyone will understand my post, Complete newbie here when it comes to this stuff, So please keep that in mind. I had a idea to turn a pair of 2 AAA battery powered headphones into rechargable ones as a project for myself. Would I be able to use the Micro-LiPo charger to do this? and if so, Where would I put the + and - wires to the board to power said headphones? Like I said, Complete newbie when it comes to this stuff, Not even sure if I am doing it right.

[adafruit_support_bill]

It should be possible to do. The first question is whether your headphones can handle the increased voltage of a LiPo,

Common alkaline type AAA cells start off at around 1.6v when fresh and the voltage declines from there. So with 2 fresh cells in series your headphones will be seeing at most about 3.2v. And somewhat less than 3v for most of the battery life.

A freshly charged LiPo will be at 4.2v and will decline to about 3.7v for most of the discharge cycle.

Assuming that your phones could handle up to 4.2v, you could just connect the '-' wire to the GND pin and the '+' wire to the BAT pin.

If you want to limit the voltage to something closer to the alkaline cells, you could wire a diode in series. A 1n4001 diode will have about a 0.8v drop. That will limit you to about 3.4v max and around 2.9v for most of the discharge cycle.

https://www.adafruit.com/product/755

[mfrye1399]

I appreciate the reply, I think I will purchase this and try it out. I'm not worried about over-voltage or breaking them considering I have multiple pairs, It's just a project that would satisfy me to do. I may purchase the 1n4001 just as a precaution.

[mfrye1399]

Now would I wire a diode through both the positive and negative terminals? or just positive?

[adafruit_support_bill]

The diode would be wired in series.
* Connect the anode (the end with no stripe) to the BAT pin.
* Connect the cathode (the end with the stripe) to the + wire of your phones.
* Connect the - wire of your phones to GND,