Factors affecting the reliability of UPS battery

As an emergency product of UPS, UPS plays an important role in all walks of life. How to ensure the reliability of ups in use? Today, I will introduce in detail the four factors that affect UPS battery.

As an emergency product of UPS, UPS plays an important role in all walks of life. How to ensure the reliability of ups in use? Today, I will introduce in detail the four factors that affect UPS battery.

1. Battery temperature affects battery reliability

Temperature has a great influence on the natural aging process of battery. Detailed experimental data show that the battery life decreases by 10% for every 5 ℃ rise in temperature, so UPS should be designed to keep battery temperature as high as possible. All on-line and backup / on-line hybrid UPS generate more heat than backup or on-line interactive UPS during operation (so the former needs to install fans), which is also an important reason for relatively long battery replacement cycle of backup or online interactive ups.

2. Battery charger design affects battery reliability

Battery charger is a very important part of UPS, the charging conditions of battery have a great impact on the battery life. If the battery is always in the state of constant voltage or "floating" appliance charging, the ups battery life can be maximized. In fact, the battery life in the state of charge is much longer than that in the state of storage. Because the battery charging can delay the natural aging process of the battery, the ups should keep the battery charging whether it is in operation or shutdown state.

3. Battery voltage affects battery reliability

The battery is composed of a single "primary battery". The voltage of each primary cell is about 2 v. the primary battery is connected in series to form a battery with high voltage. A 12 V battery consists of 6 primary cells, a 24 V battery consists of 12 primary cells, and so on. When the ups battery is charged, each primary battery connected in series is charged. If the performance of primary batteries is slightly different, the charging voltage of some primary batteries will be higher than that of other primary batteries, which will lead to premature aging. As long as the performance of a primary battery in series decreases, the performance of the whole battery will also decline. The test shows that the battery life is related to the number of primary batteries in series. The higher the battery voltage, the faster the aging.

4. Ripple current affects battery reliability

Ideally, in order to prolong the battery life of UPS power supply, the battery should always be kept in the state of "floating" charging or constant voltage charging. In this state, the fully charged battery will absorb very small charger current, which is called "floating" or "self discharging" current. Despite the battery manufacturer's recommendation, some ups designs (many on-line) allow the battery to withstand some additional small current, known as ripple current. Ripple current is generated when the battery continuously supplies power to the inverter, because according to the principle of energy conservation, the inverter must have input DC power to produce AC output. In this way, the battery forms a small charge and discharge cycle, and the frequency of the charging and discharging current is twice that of the ups output frequency (50 or 60 Hz).