In the first six months that I owned an iPhone 15 Pro Max, my battery health never dropped below 100%. This may not seem like a big deal, but considering my iPhone 14 Pro Max lost about a percentage point every month the previous year, I was extremely impressed with the battery’s ability to maintain full capacity as long after purchase.
Over the last three weeks, it hasn’t been so great. In early April, I noticed that my battery status had finally dropped to 99%, as expected after six months of daily use and charging. But in April and May it fell by about 1 percent each week and now stands at 92 percent. Even if the pace slows down a bit, there are still five months until the iPhone 16 arrives, so it’s likely that my battery health will drop to around 85% or lower.
That may not sound catastrophic, but it’s a big drop from just a few generations ago, when battery health remained in the mid-90s after a year. And that was when the iPhone battery was only guaranteed for 500 cycles. Now, Apple says the batteries in the iPhone 15 models are designed to retain 80% of their original capacity after 1,000 full charge cycles under “ideal conditions.” I’m only at 270 cycles, but the recent rate of decline has me concerned about the lifespan of my iPhone 15 Pro Max.
I don’t think I’m doing anything different than most people. I usually charge it overnight, connected to a magnetic charger on my nightstand, and maintain an 80% limit most of the time. I don’t let my phone get to zero very often, I usually charge it when it hits red, and I rarely charge it just because I’m sitting at my desk. But my battery health is still decreasing a bit.
As one igamesnews reader points out, my reliance on wireless charging could be the cause. He shared an iFixit article that examines the effectiveness of wireless versus wired charging and concludes that a lot of power is wasted when you place your phone on a wireless charger:
In two hours and 10 minutes, the phone charged from 0% to 100% and had a peak power consumption of 20W at 30% charge. The battery temperature also peaks shortly after at 30°C and begins to fall again as the battery cell fills and the mains power consumption also decreases. The total energy used to fully charge a 12.7 Wh battery was 18.25 Wh, meaning there was an energy loss of 5.55 Wh or 35.9%. That’s a lot of waste, and it’s also our best-case scenario.
This wasted energy could easily cause my battery to degrade faster than it should and be responsible for the recent degradation. However, I’m willing to bet that more than 90% of iPhone users rely on MagSafe or wireless charging to power up their iPhones — and probably won’t stop after reading this.
Granted, most people don’t check their battery status every week and many don’t even know it exists. However, they will notice their phone starting to die earlier in the day. We expect iPhones to last for many years, and with the latest chips and displays, plus 4-5 years of iOS updates, that’s usually the case. But with my iPhone 15 Pro Max, I wonder if the battery will hold up.
