What Batteries Are Used in UPS?
When buying a UPS (Uninterruptible Power Supply), besides looking at its power rating and features, the battery inside it is actually the hidden core that determines its performance, lifespan, and user experience. The mainstream market primarily features two major types: Valve-Regulated Lead-Acid (VRLA) Batteries and **Lithium Batteries.
**I. The Traditional Workhorse: Valve-Regulated Lead-Acid (VRLA) Battery
This is currently the most common technology, used for decades. Nine out of ten mid-to-low-priced UPS units you find use this type.
Its advantages are straightforward: First, low cost—both the battery itself and the UPS unit are the most affordable. Second, mature and stable technology with safety long proven. Third, easy to purchase and replace—you can find generic replacement batteries in almost any computer store.
However, its drawbacks are quite noticeable for Hong Kong environments: Firstly, they are bulky and heavy with low energy density. To achieve a certain backup time, the battery's size and weight are considerable, making them very "space-consuming" in Hong Kong's compact homes. Secondly, short lifespan—the typical design life is about **2 to 4 years**. Even with rare power outages, the battery naturally ages and needs replacement when the time comes, involving cost and effort. Thirdly, slow charging—after a complete discharge, it may take over 6 hours to recharge, making it difficult to handle frequent brief power dips. Additionally, they are quite **heat-sensitive**, as high temperatures can rapidly shorten their lifespan.
**II. The Emerging Force: Lithium Batteries
In recent years, high-end and newer UPS models increasingly use lithium batteries, especially the Lithium Iron Phosphate (LiFePO₄) cells, which offer higher safety and longer life. They are practically tailor-made for modern electronic devices and lifestyles.
The advantages of lithium batteries almost directly target the weaknesses of lead-acid: First, space-saving and lightweight—extremely high energy density means the volume and weight can be half or even less than half that of lead-acid batteries for the same capacity, offering great flexibility in placement. Second, exceptionally long lifespan—generally usable for 5 to 8 years, or even longer, essentially lasting the life of the UPS unit itself, with almost no need to worry about battery replacement during that period. Third, extremely fast recharge—usually taking **2-4 hours** to fully charge, easily handling frequent brief power interruptions. Furthermore, they have better tolerance to environmental temperatures.
Of course, its barrier is also clear: Higher initial purchase cost is the biggest hurdle.
Choosing a UPS isn't just about the external model; you must also consider what battery it uses. Lead-acid batteries are the "cost-effective" basic choice, while lithium batteries are the "efficient and long-lasting" upgrade option.
For Hong Kong users, if you value your electronic equipment, dislike hassle, and have limited living space, even though a lithium battery UPS has a higher price, its features of long lifespan, space-saving design, and fast charging make it a wise investment definitely worth serious consideration.