For years, Apple Watch users had the option of Power Reserve, a virtually useless mode that offered to kick in when the battery level was at 10 percent and deactivated everything except the time. It was like a 1970s digital watch and required a charge restart to get back to normal functionality. The new Low Power mode is miraculous in comparison. It’s virtually unnoticeable and seems to pretty much double battery life. I know because I tested it on a recent multi-day road trip. “watchOS 9’s new Low Power Mode has […] been a revelation. It no longer dumbs down Apple’s smartwatch, but merely disables some less-necessary features and reduces performance,” Apple Watch user, veteran Apple expert, and journalist Adam Engst says in his TidBits blog. “Your situation may vary, but when I’ve used Low Power Mode on my Apple Watch Series 5, I know it’s active only because it turns off the Always-On display, showing the screen when I raise my wrist.”

Balance

The key to a good low-power mode is balance. You need to reduce power consumption enough to make it worth bothering to use, but if you disable too many features, then you hamper utility. The old Power Reserve is an example of terrible balance. What’s the point unless you have no other way to tell the time, and you really, really need to know the exact time for the next few hours? watchOS 9’s new Low Power Mode is the exact opposite, an almost perfect balance of trade-offs. Some features are disabled entirely; some are reduced in efficacy or frequency; others switch off when your Apple Watch isn’t near your iPhone.  Apple has a detailed list of what’s what, but the general idea is it disables the always-on display, heart-rate notifications, background heart-rate and blood oxygen measurements, and the start workout reminder.  It also lowers the refresh frequency of several services. Incoming notifications may take longer, animations are less smooth, and making a phone call can take longer.  If your watch finds itself away from your phone, it turns off Wi-Fi, cellular, and incoming notifications. Though this only really affects the cellular Apple Watch.  I took a long two-day road trip across Europe recently and put my watch in Low Power mode to test it. The only thing I noticed was the always-on display was no longer always on. That’s it. Notifications came in like normal—perhaps they were a little late, but who cares? They seemed to be in sync with the phone, as usual. And if you use a watch that doesn’t have an always-on display, you won’t even notice that, although your battery life extension may not be quite so impressive.  When I went to sleep in the back of the van at around 11 PM, I remember being surprised that the battery was still around half full, maybe a little more. I was well into the following afternoon before I charged it, and I still had a double-digit charge percentage left.

New Lease

This is all the more remarkable because my Apple Watch’s maximum battery capacity is 79%, and the battery settings give me a “service recommended” warning. This also means that some watch operations may be hobbled in order to not strain the battery. Given this situation, it’s not unreasonable to consider using low-power mode permanently on older watches.  “The introduction of Low Power Mode in watchOS 9 gives Apple Watch wearers a chance to lengthen the usable lifetime of their existing watches by reducing power consumption to extend battery life. By switching to Low Power Mode, Apple Watches [that] were unable to make it through a full day on a single charge may now be able to stay powered,” software and web developer and Apple Watch user Weston Happ told Lifewire via email. If you’re already experiencing slowdowns thanks to a weak battery, you may not even notice the further limitations imposed by low-power mode. And as already mentioned, if you can live without the always-on display, you might not really notice much difference at all.  This is a fairly viable alternative to spending $79 for a replacement battery. Apple really did a good job with this one, and everyone can benefit.