Following Apple’s admission of and apology for battery-related iPhone performance problems, another battery issue is receiving attention — this time for MacBook laptops. Spotlighted today by VentureBeat reader Nicholas Antoniou and confirmed with reports on Apple’s Support Communities and other discussion groups, some MacBook laptops promising “up to 30 days standby time” are seeing much higher battery drain, an issue Apple technicians appear unwilling to fully test or repair.

When a MacBook’s lid is closed for a period of time, no more than 3.3 percent of the battery should be drained per day on average. Instead, some batteries are draining at 2-10 times that rate, leaving MacBooks dead after only 3-15 days, depending on the report. Some users have described 15 percent daily battery discharges even when the machine is shut down, and being told by Apple that this is “normal behavior with the new hardware generation.”

In Antoniou’s case, a 12-inch MacBook is seeing 7 percent loss per day, over twice the expected amount, leading to what he describes as a “near 0 charge at 10 days later.” After bringing his MacBook to an Apple Store under an AppleCare extended warranty, Antoniou said that technicians ran a battery diagnostic that didn’t include a test of standby time, yet claimed that the battery had passed Apple’s tests and would not be replaced.

Reaching out to Apple CEO Tim Cook directly, Antoniou said he was contacted by spokesperson Shane Barton, who told him that “there was nothing wrong with [the battery] according to Apple,” and “even blocked the local Apple store from letting me pay for a new battery.” When Antoniou suggested that there might be “a widespread problem with their laptops’ claimed standby life,” and challenged Apple on its refusal to honor the MacBook’s extended warranty, he was allegedly told, “if you want to take a legal route, feel free to do that.”

Unlike Apple’s claims of battery performance under active use, which include promises of “up to 10 hours wireless web” and “up to 12 hours iTunes movie playback” for current 12-inch MacBooks but vary across machines, the company’s “up to 30 days of standby time” claim typically remains the same across all of its laptops. While “up to” might be understood in some countries and courts as an explicit warranty caveat, promising anywhere from 0 to 30 days of standby, it could also be viewed as creating an implicit expectation of performance close to 30 days — certainly not 3, 10, or even 20.

Troublingly, reports on Apple’s own forums suggest that AppleCare technicians have recently been calling 5 percent daily discharge “expected behavior,” which would imply that 20 days of standby time was normal from Apple’s perspective — 66 percent of advertised performance. That’s markedly lower than the “below 80 percent” threshold that typically flunks batteries, making them eligible for AppleCare replacement.

Confronted by reports of Apple staff refusing to replace “working” iPhone batteries despite its pledge to do so, Apple notably dropped its iPhone battery diagnostic tests and 80 percent performance threshold after offering discounted replacement batteries to iPhone users last month. That precedent for iPhones doesn’t mean Apple will do the same for MacBook owners.

What’s the harm MacBook owners are suffering? As Antoniou suggested, it isn’t his inability to instantly resume work 30 days later, but rather trying to resume work 10 days later on an unused machine, only to discover that virtually all of its power has been lost. Even on machines with very few battery cycles, reports on Apple’s support communities vary on whether problems remain or go away after installing macOS 10.13 High Sierra. Antoniou’s machine is running that version of macOS.

It’s worth noting that MacBook standby life problems have been reported in Apple’s forums and others, for many years and across different models; unlike Apple’s active use battery life estimates, which have occasionally been the source of major controversies, questions over standby life have lingered in the background as possible solutions have been offered. OS updates, deletion of errant apps, and disconnection of certain accessories are common solutions that may or may not address a given machine’s issues. In past macOS releases, some users have seen relief after disabling Find my Mac or Wake for Wi-Fi network access, as well.

We have reached out to Apple for a response on Antoniou’s case and will update this article if and when we hear back.