I’ve figured out how to splice 2 USB heads together to make your favourite breast pump work with 2 phone battery packs.
We now have 10 hours of uninterrupted pumping action for those long trips or unreliable power sources.
The solution is so dead simple: wire 2 USB heads in series.
Geek note: Phone battery backs can output up to 5v at a time, but your pump will need up to 9V so wiring them in series gives it a theoretical upper limit of 10V.
You will need:
Two x USB Heads with some cable
One x Power plug that fits your pump (Buy at Sim Lim Tower for $1.20)
- Open up 2 x USB heads and cut the wires open. You should see 4 wires like this:
- Ignore white and green cables. Connect the BLACK wire (Head 1) to the RED wire (Head 2)
- Then wire the RED wire (Head 1) to the Positive terminal of the power connector. This is the TIP in the image below.
- Then wire the BLACK wire (Head 2) to the Negative/Ground terminal of the power connector. This is the SLEEVE in the image below.
- Test this out on a USB port that you don’t really like. IF you’ve wired it correctly, you should be able to pump while plugged into two computer USB ports. If your computer explodes, I accept no responsibility.
Now we can charge our phones and pump while on the go.
The battery packs came in.
And it works! 10 hours of pumping power on the go!