Mac Geekery

Background

The introduction of the MagSafe connector for MacBooks and MacBook Pros was NOT good news for users of iGo or Kensington airline/car/boat power supplies. Neither manufacturer has yet come out with a MagSafe tip, for reasons probably related to Apple’s patent.

This hint describes a simple method of using an iGo power supply with a MacBook. Some simple soldering is required, and following these instructions will obviously invalidate your warranty for both the power supply and your MacBook. The author takes no responsibility whatsoever for any damage caused!

If you already have an iGo (mine came with tip 4 included), this hint will set you back £2.08.

The principle is very simple: Insert an in-line plug and socket into the cable of the original Mac power supply. When connected together the power supply functions normally. In order to use the iGo, simply remove the plug and insert the iGo using tip no 4. That’s it!

Technical details

The Apple power unit supplies 16.5V (for more details see http://en.wikipedia.org/wiki/MagSafe). iGo tip no 4 produces 16.6V (close enough) AND fits into a standard 2.1 power line socket!

Parts Required

• iGo power supply (I used the iGo Juice 70) available from www.igo.com
• iGo tip number 4, (£5.95)
• DC power line socket 2.1mm (Part number JK11M from Maplin Electronics http://www.maplin.co.uk/) £1.29
• DC Power Plug 2.1mm (Long) (Part number HH61R from Maplin Electronics http://www.maplin.co.uk/) £0.79
• You also need a pair of wire strippers, a soldering irion and some solder

Steps

1. Take the original MacBook power supply and cut the low voltage cable (courage required here!). It is a coaxial cable with the core 16.5V relative to the shield.
2. Strip the wires and solder the plug onto the power supply end of the wire, and the socket onto the MagSafe end. Ensure that the cable core is soldered to the central terminal of the plug and socket, and the cable shield onto the outer casing.
3. For normal use simply insert the plug into the socket
4. For travelling, disconnect the plug, and insert the iGo using tip number 4.

Notes

1. This has been extensively tested using the iGo (70W) plugged into mains electricity in the UK, US and seven other countries, cars, boats, and empower airline sockets.
2. This should work exactly the same for the MacBook pro, though a higher power iGo may be required (eg 90W).
3. This should also work with the Kensington power supply as long as an equivalent tip to the iGo tip number 4 is available.
4. The MacBook power supply drops the output voltage to 6.8V when not plugged in (not sure why). The iGo does not. This has not been a problem so far but comments are welcomed.

This was submitted a while back (2007-07-17). Great apologies for not posting it sooner; it got lost in the queue of things I’m working on and I forgot that it was done. AK