There are many factors that affect the battery. Replacing the battery is very expensive (about 30% of the price of an uninterruptible power supply), which is very important to users. The concern is that battery failure will degrade the system. Kurt's battery technology department is here.

1. The battery temperature affects the battery.

Temperature has a great influence on the natural aging of the battery. Experimental data shows that when the temperature rises to 5 degrees Celsius, the service life of the battery will be reduced by 10%, so the uninterruptible power supply should try to maintain the temperature of the battery. Online and backup/online hybrid uninterruptible power supplies have a larger heating value than backup power supplies, or online interactive uninterruptible power supplies (fans should be installed in the former), which is also an important reason for the long replacement cycle of backup power supplies or interactive uninterruptible power supplies.

2. The charger design that affects the battery.

The continuous power supply charger is an important part of the uninterruptible power supply charger, and the charging conditions of the charger have a great influence on the life of the battery. The uninterruptible power supply battery has a long service life under constant voltage or floating conditions. In fact, the charging state of the battery is longer than the simple storage state. The uninterruptible power supply must be charged when it is running and when it stops working, because charging will delay the natural aging of the battery.

3. The battery voltage has an effect on the battery.

The storage battery is composed of a single primary battery, each of which has a voltage of about 2 volts. The primary batteries are connected in series to form a high-voltage battery. The 12 volt battery includes 6 primary batteries, and the 24 volt battery consists of 12 primary batteries. Each connected primary battery is charged after constant charging. A slight difference in the performance of primary batteries will cause some primary batteries to charge higher than other primary batteries, causing them to age earlier. When connected in series, the load performance of a single battery will decrease, and the overall performance of the battery will also decrease. The test results show that the battery life is related to the number of primary batteries connected in series. The higher the voltage of the bottle, the faster the aging speed.

Under the condition of uninterruptible power supply capacity, the voltage should be kept as low as possible in the design to extend the service life of the uninterruptible power supply battery. When the voltage does not change, the primary battery with a lower voltage in series should be selected instead of a large number of low-voltage primary batteries. The battery voltage of some uninterruptible power supply manufacturers is relatively high, because the voltage and current are relatively small in the case of uninterruptible power supply capacity, so thinner wires and smaller semiconductors can be used to reduce the cost of uninterruptible power supplies. The battery voltage is about 1KVA, generally 24-96V.

4. The impact of battery ripple current on battery reliability.

In theory, in order to extend the service life of uninterruptible power supply batteries, the total battery power is required to maintain a floating or constant voltage charging state. In the electrical state, a fully charged battery will absorb charging current, which is called floating or self-discharge current. Although the battery manufacturer recommends this, some continuous power sources (many of them are online) will cause the battery to generate some extra small current, which is the so-called ripple current. Because the inverter must input DC to generate AC output, the ripple current of the battery pack continuously supplies power to the inverter through the battery. The battery pack forms a small charge and discharge cycle, and its charge and discharge frequency is twice as high as the output frequency of the uninterruptible power supply (50 or 60 Hz).

Normally, there is no ripple current in the standby, online interactive, or post/ferromagnetic UPS, while other UPSs vary according to their specific design methods. Whether the continuous power supply generates ripple current can be judged by the structure diagram.

In the online uninterruptible power supply, when the battery is between the charger and the inverter, the battery generates ripple current, which is called the secondary conversion of the ordinary uninterruptible power supply.

When the battery pack has nothing to do with the cut-off tube, relay, converter or rectifier, the battery does not produce fluctuating current. Obviously, the uninterruptible power supply designed by uninterruptible power supply is not always online, so it is called hybrid backup/online uninterruptible power supply.