I turned my old laptop into a NAS, and its built-in battery replaced a UPS I never had to buy

Published Oct 26, 2026, 2:31 PM EDT Abid covers consumer hardware, gaming, and platform updates with an emphasis on accuracy, clarity, and reader-first context. He holds a BSc in Computer Science and Engineering, and his work can be found in multiple publications, including Notebookcheck. Outside of work, he enjoys exploring new gaming hardware, testing system performance, and keeping up with developments across the broader tech landscape. Given that I don't work with large files all the time, my storage needs are pretty modest. As a matter of fact, after trying out beefy five-bay and six-bay models, I settled on a compact all-flash system, and it currently has only two of its drive slots occupied. While it doesn't have a high power requirement, pairing it with a UPS feels like an unnecessarily complicated solution to keep the system running during power outages. So instead of buying another device that would just make my setup messy with extra cables, I converted my old laptop into a NAS, and it turned out to be a much more practical solution. A laptop battery solves one of the biggest headaches of running a NAS Power outages don't have to abruptly stop the transfers While it's easy to restart an interrupted file transfer, dealing with filesystem issues and corrupted files after a power outage isn't. That's basically where the UPS steps in, but I wasn't just ready to add another element to my basic NAS setup to prevent such power outage-related issues. Yes, a portable NAS could work, since they often come with built-in batteries that can provide enough runtime to shut the system down safely. However, I realized I don't necessarily need to buy one to get the same benefit. I had an old laptop collecting dust in my closet, and it ticks most of the boxes for meeting my storage needs. The internal battery, even though it doesn't have full charging capacity now, can keep the system running when the main power disappears. Low-power laptops can run for hours on battery Especially when the workload is light A big advantage of converting my old laptop into a NAS is that I don't have to worry much about power consumption, especially when it's not doing anything demanding. My setup uses a Ryzen 5 4500U, an older Zen 2 processor, and while it's not as efficient as modern CPUs, its idle power draw isbetween 3.2W and 8.7W. When the laptop NAS handles low-to-medium serving workloads, power consumption can reach around 12W. With the 46Wh battery, this 12W power draw means that I can expect around 3.5 hours of runtime when the system isn't connected to the charger. If I need more than 3.5 hours of backup power, I can simply connect a power bank. Of course, not all older laptops support USB-C charging, but a Type-C-to-barrel adapter can fix that easily. My laptop NAS can shut down safely when its battery runs low Battery monitoring helps to protect the data on my NAS The laptop's built-in battery does more than just keep the system running when the power goes out. It also lets the NAS avoid corrupted files or filesystem issues, as the system can shut down safely when the battery runs dry. Another notable aspect is that its battery status can be easily monitored on Linux. With the data from system interfaces like /sys/class/power_supply/, I can also trigger a script when the battery percentage drops to around 15%. For example, this script can safely stop important services, let pending file operations finish, unmount filesystems when needed, and shut the system down. You can get similar flexibility with a dedicated UPS, but through shutdown software and USB monitoring. The laptop, on the other hand, comes with built-in power-monitoring hardware, eliminating the need to rely on external hardware. My storage needs from a NAS make a separate UPS unnecessary But the same might not be true for all I repurposed an old laptop as a NAS because my storage needs are modest. The workloads my setup handles aren't taking a heavy toll on the system's built-in battery either. However, that won't hold for someone who needs a NAS with multiple drives and room to expand. Battery health is another consideration, even for those with modest storage needs. My laptop's battery, for example, has lost some of its original capacity and will lose more over time. For longer runtimes, I may be able to get away with a power bank, but if a system needs to stay on during extended power outages, a UPS with a suitably sized battery is the way to go. For me, though, buying a separate UPS would add cost and clutter without offering enough practical benefit.