First of all hello, I'm new in the arduino community so don't be bad with me : , so the problem is that I'm planning to make a bluetooth speaker powered with a phone battery which is Li-Ion 3.7V and I'm looking for Li-Ion usb chargers for 3.7V and I found this but as I'm new in this, I don't know if this will work, or if it will make my battery die, so I'm so glad If you can help me :-[ The usb charger is this:
Another thing is...In case this work how should I connect the battery, I mean for charging I know It will be B+ and B- but If I just want to use it to power the speakers I should solder again another cable from the positive of the battery to OUT+ and from the ground og the battery to OUT- ?
Thanks for read and sorry if this is a newbie question