UPS, or uninterruptible power supply, is a device that provides backup power in the event of a power outage. UPS systems come in different sizes and capacities, from small units that can keep a computer running for a few minutes to large units that can power an entire building for. Most UPS systems have batteries that are sealed lead-acid (SLA) batteries. These batteries don't require routine maintenance, but they will need to be replaced every 3-5. If you have a UPS that you've never used, it's important to charge it. Here's how to do so: 1. Plug the UPS into a wall outlet and let it charge for 24 hours. 2. Once the UPS is fully charged, plug. Like most people, you probably don't think about your UPS until the power goes out. But if you want to be prepared for the next outage, it's good to know how to turn on your UPS. Here's a. Do you have an uninterruptible power supply (UPS) for your computer? If so, you may wonder if it's better to keep it plugged in all the time or only.