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Apple-Supplied MacBook Battery Weight Matters

I buy a lot of aftermarket batteries for MacBooks, and judging by weight, it is very clear that 3rd party batteries are significantly lighter than the originals.

That means that the aftermarket batteries simply cannot provide as much power.

Analysis:

There are three major parts to a laptop battery:
  • The housing, made of plastic and/or aluminum
  • The battery management electronics and power connector
  • The lithium cells
So let's think of everything that makes up a battery except the lithium cells: It seems like a good bet that a genuine Apple battery's housing and electronics has roughly the same weight as an aftermarket battery.  For argument's sake, let's say that a battery unit weights 100 grams PLUS the weight of the cells.

That implies that a lighter battery has smaller (or fewer) cells!

For example, I have a genuine MacBook battery that weights 364 grams.  My aftermarket battery weighs 230 grams.  Assuming that 100 grams is for non-cell componentry, that means the genuine battery has 264 grams of energy cells versus 130 grams of energy cells for the aftermarket battery. 

Doing the math, that means that a genuine MacBook battery has more than twice the battery than the aftermarket battery.  Although the batteries are rated the same, it is virtually impossible that these devices actually deliver the same power.

What about my battery?

Each factory-delivered Apple battery model has a weight.  Below is a list of original MacBook batteries that I've measured.  Check to see how your MacBook battery measures up!

MacBook Air, 13 inch 

Apple Battery Model Number: A1405
Power Label: 7.3VDC, 50Wh, 6700mAh
Official Battery's Weight: 296 grams (Source: MacBook Air 13-inch (mid-2012) 020-7379-A)

All of these MacBook Air models use the A1405 form factor:
  • Apple MacBook Air 13 inch, Late 2010
  • Apple MacBook Air 13 inch, Mid 2011
  • Apple MacBook Air 13 inch, Mid 2012
  • Apple MacBook Air 13 inch, Mid 2013
  • Apple MacBook Air 13 inch, Early 2014
  • Apple MacBook Air 13 inch, Early 2015

MacBook Pro, 15 inch Unibody

Apple Battery Model Number:  A1321
Power Label: 10.95 VDC, 73 Wh
Official Battery's Weight: 450 grams (Source: MacBook Pro 15-inch (mid-2009) 020-6380-A)

The following MacBook Pro models use the A1321 form factor:
  • MacBook Pro 15.4 inch, Mid 2009
  • MacBook Pro 15.4 inch, Mid 2010

MacBook Pro, 13 inch Unibody

Apple Battery Model Number:  A
Power Label: 10.95 VDC, 73 Wh
Official Battery's Weight: 450 grams (Source: MacBook Pro 13-inch (mid-2009) 020-6380-A)

The following MacBook Pro models use the A1321 form factor:
  • MacBook Pro 15.4 inch, Mid 2009
  • MacBook Pro 15.4 inch, Mid 2010
Aftermarket Weight:

MacBook, 13 inch Unibody (white)

Apple Battery Model Number:  A1331
Power Label:10.95 VDC, 63.5 Wh
Official Battery's Weight: 364 grams (Source: Three MacBook 13-inch (mid-2010) 020-6809-A batteries)

The following MacBook models use the A1331 form factor:
  • MacBook 13 inch, Late 2009
  • MacBook 13 inch, Mid 2010
My aftermarket A1331 compatible battery:
Rating Label Claim: 10.95V, 5800mAh/63.5Wh
Weight is 270 grams.

My latest aftermarket A1331 compatible battery:
Rating Label Claim: 10.95V, 5800mAh/63.5Wh
Weight is 230 grams.  Atrocious!

MacBook, 13 inch (white, non-Unibody)

I haven't measured a genuine Apple battery for these models, but I do have details for my aftermarket battery.  If you have a genuine Apple battery, please let me know the details!

Apple Battery Model Number: A1185
Power Label:
Official Battery's Weight: ??? grams (Source: Maybe you?  Let me know!)

The following MacBook models use the A1185 form factor:
  • MacBook 13 inch, 2006 through mid-2009
My aftermarket A1185 compatible battery:
Rating Label Claim: 10.8V, 5600mAh/60Wh
Weight is 280 grams.
Note: the aftermarket battery has a housing that is all plastic, instead of partially aluminum

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