Oh No! Wrong Power Adapter?

[splitpea]

Just realized that I brought the 45W MBA adapter instead of the 65W adapter for my 13" rMBP on a 10-day trip. I know it's bad for the battery to use a lower-wattage adapter. Just how much damage will I do in a week and a half? Are there certain charging patterns to adhere to or avoid that will mitigate it? Should I avoid using the computer at all once the initial charge runs down?

 

[snaky69]

I know it's bad for the battery to use a lower-wattage adapter.

Says who? I'd say you or whoever told you this pulled it out of a place where the sun doesn't shine.

The power adapter is a source, the battery is the one that decides how much juice to draw at any one time. Using a lower or higher wattage power adapter will not harm it. You may notice slower charging, and even steady discharging when pushing the computer, because the power adapter will not be able to provide enough power for the computer. That's about it.

 

[T5BRICK]

I know it's bad for the battery to use a lower-wattage adapter.

No it isn't. It'll just charge slower.

Just how much damage will I do in a week and a half?

None, but it might be annoying if you're really pushing the computer and the battery level starts dropping even when you're plugged in.

Are there certain charging patterns to adhere to or avoid that will mitigate it? Should I avoid using the computer at all once the initial charge runs down?

Just use it and don't worry about it.

 

[chipchen]

Yep, it's fine. Just slower.

 

[simonsi]

I know it's bad for the battery to use a lower-wattage adapter.

Nope - where did you hear that?

 

[maflynn]

You won't damage it, as mentioned by others, though it may not charge up very fast.

 

[splitpea]

Hm, maybe that's an issue just with older hardware? I remember warnings from the pre-retina MBP days that a too-low-wattage charger wasn't just slow, it could be harmful to the battery/charger. Thanks for setting me straight, folks!