I would like to know if I am able to use a 45W MagSafe Power Adapter in my MacBook Pro Retina 15 with a MagSafe to MagSafe 2 Adapter.

I am normally using the original one (85W MagSafe 2 Power Adapter) but I just want to know that the computer will charge correctly and that the battery won't be hurt.


It will charge. However, it will do so very slowly.

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  • agree - it may, in fact, not keep up if the machine is in heavy use. – Tetsujin Mar 13 '15 at 19:29
  • only good for overnight use – Ruskes Mar 14 '15 at 2:16
  • The other thing to bear in mind will be heat - I've used the charger for my 13 inch MacBook with my 15 MPB - it works, but gets very warm. I suspect this will decrease the life of the charger as well. – agentroadkill Mar 16 '15 at 20:34

I am using the original apple 45W charger from my old MB Air with the magsafe 2 adapter on my MBP 2016 and I haven't had any problems in the last 2.5 years.

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I've been using the MacBook Air 45W power adapter with my MacBook Pro Retina 15" and it works perfectly. Charging takes a little longer than with the original power adapter. I recommend the 45W adapter for travel.

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