Mac notebooks: Reducing cable strain on your MagSafe power adapter
Proper usage and maintenance of the MagSafe power adapter can substantially increase the life of the adapter.
While the MagSafe power adapter is designed to travel with your Mac notebook, certain usage patterns can contribute to the fraying or breaking of cables. The MagSafe adapter, like any other metal wire or cable, is subject to becoming weak or brittle if repeatedly bent in the same spot. Follow the recommendations below to reduce the likelihood of damaging the adapter.
The most important way to maintain adapter health is to regularly inspect the cables, connectors, and the adapter itself for any kinks, breaks, bends, or other damage. Should you find any such damage, discontinue use of the adapter.
Setting up and using the adapter
When unwrapping the cord from the adapter, be sure to support the weight of the adapter (Figure 1). If the connector is held and the weight of the adapter is used to unfurl the cable (Figure 2), the cable or the adapter itself could be damaged.
Figure 1 Unwrapping the cable while supporting the adapter
Figure 2 Unwrapping the cable by letting the adapter fall
Excessive bends in the cable may ruin the cable over time. The most likely points where excessive bending may occur are near the adapter brick (Figure 3), or the MagSafe connector itself (Figure 4 and Figure 5). Ensuring slack in the cable at these particular points (Figure 6) preserves the durability of the adapter. Aim for gentle curves instead of angles. Proper usage increase its longevity.
Figure 3 Bending by the adapter brick
Figure 4 Strain at MagSafe connector on T-style adapter
Figure 5 Strain at MagSafe connector on L-style adapter
Figure 6 Slack at MagSafe connector on T-style adapter
Using the Two-Prong "Duckhead" AC Plug or Three-Prong Power Cable
If you are using the two-prong "Duckhead" connector for your MagSafe adapter and you find the cable barely reaches, switch to the three-prong, grounded connector to improve the reach of the cable and reduce strain. Figure 7 shows the length of the adapter with the Duckhead and Figure 8 shows the length of the adapter using the three-prong, grounded connector which is much longer.
Figure 7 Two-prong Duckhead connector
Figure 8 Three-pron, grounded connector
Routing the adapter cable
Mac notebooks have the MagSafe connector on the left side of the computer. With the T-style adapter, if you need the cable for the adapter run to the right side of the computer, run the cable around the back (Figure 9) instead of under the computer (Figure 10). When using the L-style adapter, never run the cable along the ports with the connector plugged in backwards as this will make it very difficult to disconnect. Make sure there is plenty of slack on the connector side and that the connection is not strained (Figure 14).
Figure 9 T-style adapter cable run around the back of the computer
Figure 10 T-style adapter cable run under the computer
Figure 11 L-style adapter cable routed along the I/O ports
Always keep the area around the adapter and its cabling clear. Some items that come into contact with the cable could cause significant damage. The cable shown in Figure 10 is likely to be run over by the wheel of the chair which could cause a break inside the cable.
Figure 12 Cable likely to be damaged by objects in the workspace
Disconnecting and storing the adapter
Properly disconnecting the MagSafe connector from the computer can prolong the life of the adapter. Using the connector itself instead of the cord is discussed further in Mac notebooks: How to disconnect the MagSafe power adapter.
The 'wings' (Figure 13) allow the cable to be stored with the adapter using a very small footprint. Note that improper wrapping of the cord on these 'wings' may cause issues similar to bending the cable. When wrapping up the cabling, be sure there isn't additional strain on the cable where it connects to the adapter brick. Figure 14 shows excessive stress and Figure 15 shows proper wrapping. Wrap the cable loosely to avoid creating undue stress or harsh angles with the adapter.
Figure 13 Wings open to accept the cable
Figure 14 Excessive strain on cable when wrapped
Figure 15 Properly wrapped cable
If the computer is being used regularly in the same locations, consider obtaining an adapter for each location. Having a dedicated power source in each location limits the need to setup and store the adapter on a frequent basis and helps avoid potential strain relief issues all together.
Whether your product is in or out-of-warranty, you can take your adapter (you don't need to take the computer, however please do bring the computer's serial number) to an Apple-Authorized Service Provider or Apple Retail Store for evaluation and replacement if necessary. You may be eligible for a replacement adapter free of charge. Make a reservation at the Genius Bar before visiting your local Apple Retail Store. To make a reservation, go to http://www.apple.com/retail/geniusbar/ (available in some countries only).
If you received a notice that referred to Apple's Power Adapter Replacement Program, please view About Apple's Power Adapter Replacement Program -- U.S. only, to learn about strain relief and to learn how to obtain a replacement adapter if eligible.
For information on properly disconnecting the MagSafe power adapter, see Mac notebooks: How to disconnect the MagSafe power adapter.