ITS current that causes overheat ,but if the battery is 450 ma i would guess it draws 75 ma to 100 ma,so its a very little load on your EZB.

So you will not have a problem,i have a bluetooth speaker that uses USB input also,haven't had a chance to hook it up yet.

There is another problem if the speaker uses USB its not a good idea to ,use the 5 volt usb input. Reason is that you using a battery to charge a battery ,5 volt usb input charging 3.7 volt battery

So the solution is remove the battery and attach 2 wire to it from the regulator board and have the board adjusted at 3.7 .

I use two of those exact converters in my robot. They work great and are fully adjustable. I did, as Rich says, connect to the battery and not the EZ Board.

Good luck with your build!

I agree with @Rich & @Herr Ball, tap into the battery with the voltage regulator ( voltage converter), modify voltage as needed ( 3. 7v) and leave EZ-B alone.

I would say the say thing,no problems overheating or making the 5 volt regulator very hot if you tap in using the battery and might last longer.

Second i would remove the 3.7 volt battery you don't want to charge a battery with another battery.

Ok so I will go with connecting it to the battery direct and will set it up to allow 3.7-4v

4 volts might be to high voltage for that circuit,i would say 3.6 volts to 4.8 volts and mostly you check it under a load hope this helps you TECHNOPRO

@robotmaker, 4 volts will not be too high, a 1s LiPo cell when fully charged has a voltage of 4.2 volts. 4.8 volts on the other hand would be too high, I assume a typo?

@Technopro, stick with your last thought, the 3.7v to 4v regulator. 3.8v is probably the best voltage to set it to since this is the "official" rating of a LiPo cell. Although a week since your post I assume you may have tried this already? Have you had any luck or any further problems?

Don't forget to mark this one as solved once it is solved