"The most important thing when buying a UPS is to look at the backup time!" After all, when a power outage hits, the longer your machine keeps running, the more room you have to react. But exactly how long can a UPS actually hold out?
First, regardless of the battery type, the core formula determining backup time remains the same: it's a contest between "battery capacity" and "total power consumption of your devices." This means the more power-hungry your computer, NAS, and other connected gear are, the shorter the backup time will naturally be.
Lithium Battery UPS: It's Not About Lasting Longer, But Lasting Better
If you expect a Lithium Battery UPS to miraculously double the backup time for the same setup, you might be disappointed. Given the same power rating and battery capacity, its initial backup time is roughly similar to that of a traditional lead-acid battery version.
So, where does the higher cost of a Lithium Battery UPS go?
First, it's incredibly space-efficient. Lithium batteries, particularly Lithium Iron Phosphate (LiFePO4), have a high energy density. To achieve the same backup time, their volume and weight can be over **50% less** than old-style lead-acid batteries.
Second, their lifespan is astonishingly long. With a traditional lead-acid battery UPS, you'll typically notice a significant drop in backup time after just two to four years, meaning you need to prepare for a battery replacement. A Lithium Battery UPS, however, easily lasts **five to eight years**, essentially keeping pace with the lifespan of the main unit itself.
Third, recharging is lightning-fast. This is crucial for Hong Kong's occasional, sudden power dips. A lead-acid battery might dawdle for **six to eight hours** to fully recharge, while a lithium battery can be ready in as little as **one to two hours**. Right after one outage, it's quickly back at full strength, ready for the next, offering much greater peace of mind.
III. Practical Estimates: How Long Can Each Technology Actually Last?
Let's look at some real-world scenarios (based on new batteries and medium load):
* **Office Computer (approx. 200W)**: Using a 600-800VA UPS, it can provide roughly **10 to 20 minutes** of support—enough for safe saving and shutdown. This duration is nearly identical for both lithium and lead-acid versions.
* **Gaming/Design PC Combo (approx. 400W)**: With a 1000-1500VA UPS, it can last about **5 to 10 minutes**. The lithium version similarly provides time for a proper shutdown, not for continuing an intense gaming session.
* **Home NAS (approx. 50W)**: For such low-power-consumption devices, even a smaller UPS might support it for **over an hour**. For a NAS that needs to run constantly, the "longevity" of a lithium battery is particularly appealing, eliminating worries about battery degradation after just a couple of years.