Two factors that affect backup battery
Support the infrastructure of modern society must be based on a very high reliability of operation are based. Internet and telecommunications switching center server farms to ensure nearly 100% of the "trouble-free run-time" or availability of the system, they are usually only a very mature technology - lead-acid batteries, A1175 ， A1185 ，M8403 , apple iBook G4 12 inch batterywhile the Data Storage Center used high-tech. In general, these key nodes, and many other important sectors are equipped with standby power, standby power is usually the first stage inverter, inverter pairs of VRLA (VRLA) batteries or a similar performance, sealed gel batteries mounted battery section Power Conversion.
The reason why traditional techniques are widely used, there are many reasons, affordable, especially lead-acid batteries, but also with outstanding reliability. But while large, but not perfect. VRLA Battery life is limited (typically 12 years design life), which changed often mission-critical systems such as battery backup power supply, but regularly. Errors can occur, indeed. In a typical standby power system, the role of the battery as the name implies - they always get a fully charged state of waiting for the main power failure. And get the fully charged state of continuous flow through the small "float" free of charge. If the float current is below a certain threshold, then the battery in the gases produced by electrolysis of re-chemical combination. In this case, a single battery float voltage is even slightly higher than the standard value of 2.27 V, so the battery can be corrupted. Slightly over-voltage will cause precipitation of the electrolyte capacity of more than recombination more gas, these gases are not covered by the valve. If the battery temperature is too high, even if the charging voltage is suitable, the loss of electrolytes.
Other modes include errors early sulfation, can accelerate very bad columns and grid connection, grid connection and the poor record, acid stratification and grid corrosion. There is another, albeit a small but catastrophic failure modes - thermal instability, the VRLA gel batteries own, and failure modes may lead to bursting into flames. The only way to prevent, thermal runaway is to monitor the internal temperature of the battery.
Simply monitoring the battery voltage on the detection of lead-acid battery capacity decline of the role is very limited, it has been recognized throughout the industry. When the battery power decreases, it is usually shown that the voltage, until the appearing of the great rivers only visible, but if his performance has been significantly reduced voltage drop prematurely. By measuring the proportion of electrolyte to determine the exact battery status, the method of the VRLA or sealed gel batteries do not apply; routine test battery used in the only way is to take the battery to a state controlled by the the dismissal, but this approach must stop using the battery. In addition, the depth of discharge is also lead the life, reduced-acid battery to test at regular intervals on its backup battery discharged, as well as lead his main power supply with high reliability of the system, most programs use this test to the to determine battery life.
More recently, continuous monitoring can be a non-intervention electronic method can detect a single cell in the vicinity of state failure, this method not only can save costs while maintaining overall system availability. The predecessor of the cell or battery pack systems is usually measured (battery industry term apple PowerBook G4 15 inch battery，A1045that means that within the shell in the same package multiple battery) voltage - is well known, despite its limitations - with charge / discharge current and ambient temperature. Some systems attempt to measure or guess the battery internal resistance, varying its effectiveness.
LEM Sentinel system is on the basic parameters of a simple analog measurements of change leading product has now grown to depend on the first three generations of the Sentinel III. It is custom-designed single-chip SoC (system on chip) IC on the integration of analog and digital technology. The device configured in a measured terminal voltage, battery temperature and internal resistance of the module may again be able to offer in most of the backup system configuration, provide accurate measurements for the costs within the budget of the system, it is a draft key elements.