Hi Guys,
I have brought a bluetooth receiver which I would like to power with my 12v 7000mah battery.
The bluetooth receiver has a rechargeable battery, the only info I have on this is that it is 140mah.
I want to remove the battery that is inside and power off of the 12v battery.
I am assuming that the bluetooth unit is 5v as it can be charged through USB.
How would I step it all down to the appropriate wattage/amps/volt.
I tried using a 12v to 5v car usb adapter but it burnt out the board. I think this is because 7000mah was going through it.
Any help would be greatly appreciated. Is there any more info that you guys would need from me?
I think I just need to use resistors, but I am confused with how to use a calculator to work out what I need.