Battery Replacement or upgrade

Hi Anthony,

The answer to that is a qualified no. There are some models of laptops that come with what are considered user-replaceable batteries, and some of them offer higher capacity options for their battery packs. This generally comes at a cost, though, in the form of a larger pack that tends to stick out from the laptop or otherwise take up more room and be less streamlined than the normal capacity battery.

Note that only applies to the kind of batteries I mentioned, the user-replaceable ones. MacBooks do not fall into that category, as their batteries are not considered "user replaceable" in the industry sense of it normally taking no tools or a minimal amount (like one or two screws) to replace the battery.

Anyway, Lithium Ion batteries do not have a higher power density option, meaning they aren't like going from Ni-Cd to NiMH where you get a big jump in power density such that you can increase the mAh the battery can supply. So you're stuck with the fact that the amount of power a given Li-Ion battery can hold is strictly determined by its physical size, and the only way to add more storage is to make it bigger.

MacBooks, and similarly iPhones, have no extra room for the battery to grow. The batteries they use are custom designed to occupy the maximum amount of space possible inside the case, which means they're as big as they can ever get. The inescapable conclusion is that the batteries are as big as they can be, and thus have as much storage as is physically possible.

So the short answer is no, you cannot increase the amount of power storage available in a MacBook battery, at least not significantly. You may find aftermarket replacements with a slightly higher mAh rating, and that's all well and good, but you're not going to see any that are like half again or bigger in size. You can be sure that the ones that claim to have far more power than the originals are almost certainly lying, similar to the old "gold" high capacity batteries that were being sold for older iPhones like the 4, 5 and 6. Those turned out to be a complete scam; they were just ordinary batteries being sold at a premium price with untrue claims of power density. Our own @oldturkey03 debunked that myth in his excellent guide.

The myth of the "high capacity" batteries - iFixit Repair Guide