「大容量」バッテリーの神話

I would add a second warning, from my experience/forced education with iPhone batteries about five years ago. The situation may have changed. But at the time, I was seeking affordable batteries for refurbished phones. So I tried eBay. And tried, and tried. Exactly one supplier (iFixit moderators, am I permitted to name the supplier?) provided full capacity (that is, full standard capacity) batteries that were accurately described. Every other supplier I tried was selling batteries that were far below standard capacity—some of these were “gold” batteries and some were standard.

So at least at that time, it was far from safe to buy gold batteries even if all one wanted was a standard capacity battery. The reality seems to be (or seemed to be) that these are batteries taken from used phones and sold as new regardless of their age, storage conditions, or existing capacity. That was the norm, not the exception.

If you’re going to be buying a lot of batteries, find a supplier you trust. I hear iFixit is good….

By the way, thank you for publishing this, and for doing such a thorough and careful job. I learned this the hard way.

It’s perhaps worth pointing out that maximum capacity of a battery of a given chemistry (e.g. lithium ion) is limited by size—hence your careful measurements in step 2. A battery with 50% more maximum capacity (i.e. capacity before degradation by aging and use) is going to be 50% bigger. You obviously know this, but it’s worth pointing out to people like me whose high school physics teachers are rolling over in their graves (or just rolling their eyes, depending on your age) when their former students are taken in by these things.

There are some new chemistries for lithium batteries, I understand, and I understand that they do have somewhat higher capacities. But that’s not what these gold batteries are. I even took the gold labels off some of the ones I bought and found the original labels beneath…

Maybe the author, or someone else could do a follow-up post? It seems that “high-capacity” batteries have proliferated, despite proof of false advertising. I even purchased a “high-capacity” battery off Amazon to repair my iPhone 6S Plus. The new battery seems like it holds a charge extremely well. I don’t remember the exact specs, approx. a 3500 mAh “high-capacity” battery vs. factory Apple battery ~2750-2850 mAh. Granted, I purchased my replacement battery before stumbling across this article & I really wonder whether any of the manufacturer’s are ACTUALLY providing accurate mAh ratings, currently. Some manufacturer’s are much more accurate with their product descriptions, build quality & capacity ratings. I just thought it would be a very interesting, and a very telling follow-up article to show whether or not manufacturer’s have changed any of their advertising practices since this original article. I challenge anyone out there to make this happen, and share with us their results, thanks!

Very well executed test here, but it would be nice if we can have different brand of these ‘high capacity' batteries get tested against each other as well.