The life of yuasa battery in UPS power supply

Even if UPS uses the same battery technology, the battery life of different manufacturers is very different, which is very important for users, because the cost of battery replacement is very high. Battery failure will reduce the reliability of the system, which is very annoying.

1. Temperature influence

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

2. Charging impact

UPS power charger is a very important part. The charging conditions of yuasa battery have a great influence on battery life. If the battery is always in the state of constant voltage or "floating" electric appliance charging, the ups battery life can be improved to the greatest extent. In fact, the life of the battery in the state of charge is much longer than that in the state of pure storage. Because battery charging can delay the natural aging process of battery, UPS should keep battery charging no matter in operation or shutdown state.

3. Voltage influence

The battery is a single "primary battery". Each primary battery has a voltage of about 2V. When the primary batteries are connected in series, they form a battery with a higher voltage. A 12V battery is composed of 6 primary batteries, a 24V battery is composed of 12 primary batteries, etc. When the ups battery is charged, each primary battery connected in series is charged. If the performance of the primary battery is slightly different, the charging voltage of some primary batteries will be higher than that of other primary batteries, and these batteries will age in advance. As long as the performance of a primary battery connected in series declines, 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 is, the faster the aging is. When the ups capacity is fixed, the battery voltage shall be kept as low as possible during the design, so that the longer the ups battery life is. When the battery voltage is fixed, the number of batteries in series with small voltage and high voltage shall be selected, and the number of batteries in series with large voltage and low voltage shall not be selected. The battery voltage of some ups manufacturers is relatively high, because when the capacity is fixed, the higher the voltage is, the smaller the current is, and the thinner wire and the semiconductor with smaller power can be selected, so as to reduce the cost of ups. The battery voltage of ups with capacity of about 1kVA is generally 24-96v.

4. Current effect

Ideally, in order to extend the ups battery life, the battery should always be kept in the state of "floating" charging or constant pressure charging. In this state, the fully charged battery will absorb a very small charger current, which is called "floating" or "self discharging" current. Although battery manufacturers recommend this, some ups designs (many in-line) make the battery bear some extra small current, which is called 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 to generate AC output. In this way, the battery forms a small charge and discharge cycle, and the frequency of charge and discharge current is twice of UPS output frequency (50 or 60Hz).