A life indicator of stationary type sealed lead-acid battery

To determine a life span of a sealed lead-acid battery, it is important to measure an internal impedance and an operating temperature. The authors describe a battery life indicator which applies these measurements for overall life determination. The major features are as follows: the life indicator can digitally display the number of remaining years of battery life from installation until the end of life of a sealed lead-acid battery during floating charge, without disconnecting a load from the battery; and the life indicator can be realized by the use of a simple circuitry because a measuring current for internal impedance can be supplied through a commercial transformer without use of an inverter.<
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