DIY Bluetooth Headphones 6 Steps with PicturesSolder 3 wires to the battery. The middle one is used to determine whether the battery is chargingblue wire on the picture. OaQcLgd8L_400.jpg' alt='Where Is The Serial Number On Sennheiser Headphones' title='Where Is The Serial Number On Sennheiser Headphones' />Attach all three wires to the power connector and then extend wire to the second leg of the power switch. Once done mount the power connector 3. Make sure you dont block the Bluetooth module. If your battery is loose stick it to the back side of earphone housing and put a little hot glue to its sides. Do not overheat the battery, because it may stop working or explode Test power connector and power switch, before putting everything together. Ive used my old phone as power supply, because I only had one spare 7. V adapter, which happened to be a charger from my battery donor phone Ill try to come up with more permanent solution in a few days, but this would do for now. Charging only requires a steady supply of at least 5. A at 3. 5 4. V. you can use any charging device or power supplyjust dont use the middle wire from the battery, but you wont be able to see whether it is fully charged or not. There is also a danger of overcharging the battery shortens its life and may cause overheating. Where Is The Serial Number On Sennheiser Headphones' title='Where Is The Serial Number On Sennheiser Headphones' />Buy AKG K702 Reference OpenBack OverEar Studio Headphones. Free delivery and returns on eligible orders. Reviews 382httpswww. IDSERP,5226. 1Audiogd Master 11 DAC Headphone Amplifier 2743. Install Windows On Mac Powerbook G4. Accessories Amplifiers Analog Cables Computer Audio Digital Headphones Home theater Integrateds Miscellaneous Music Power Preamplifiers Speakers Systems Vintage Equipment. In todays hectic and noisy world, we are all searching for a little peace and quiet. Well, you might not be able to slip off to a tranquil forest for an hour or.