Uninterruptible power supply units

The uninterruptible power supply unit, unlike the processor or even the monitor, has a certain service life, about three years after which the user should - change the choice accumulators or to get new UPS? But most often in three years the computer acquires accessories which would be also quite good to be connected via the UPS, at least to bring order to wires. And considering the cost and complexity of replacement in the UPSes some models of rechargeable batteries, it is very frequent after the corresponding bulb on the UPS case lights up or after suddenly it is not able to protect your computer from loss of tension in a network, the user just buys to himself the new uninterruptible power supply unit.