Monitoring system for batteries during charge and discharge
First Claim
1. A monitoring circuit for a battery while said battery is being charged or discharged, where said battery comprises a series of modules connected in series, and where a terminal is placed between each adjacent pair of modules and at each end of said battery, so that the voltage across each module may be measured at the pair of terminals defining the module, said monitoring circuit comprising:
- means for periodically interrupting the flow of current to or from said battery for an interruption interval of fewer than about 2 to 10 ms;
means for selectively sampling the voltage of any one of said modules, during an interruption of current flow, so as to make a determination of the resistance free voltage of that module;
means for comparing said resistance free voltage of the module against at least two reference voltages, to determine if said resistance free voltage is above a first predetermined level or below a second predetermined level; and
means for causing an alarm indication in the event that said resistance free voltage is found to be either above said first predetermined level or below said second predetermined level.
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Accused Products
Abstract
A monitoring circuit is provided to monitor batteries while they are being charged or discharged, where the batteries comprise a series of modules or cells that are connected in series. A terminal is placed between each adjacent pair of modules and at each end of the battery, so that voltage across each module may be measured at the pair of terminals that define the module. Several different determinations of module voltage may be made during charge and/or discharge of the battery including the resistance free voltage of the module, and the module voltage while current is flowing through the battery. Generally, some or all of the modules are tested periodically, where the interruption interval for internal resistance free voltage determination may be in the order of 2 to 3 ms, and the testing frequency for the battery may be in the order of 0.5 to 25 Hz. Alarms may be triggered in the event of module voltages being sensed that are outside of predetermined limits, meaning that the charging and/or discharging characteristics of any of the modules has changed and is significantly different than those of the other modules. By such alarm indications, the module may be changed before serious damage occurs to the battery, either by overcharging or severely discharging the battery.
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Citations
11 Claims
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1. A monitoring circuit for a battery while said battery is being charged or discharged, where said battery comprises a series of modules connected in series, and where a terminal is placed between each adjacent pair of modules and at each end of said battery, so that the voltage across each module may be measured at the pair of terminals defining the module, said monitoring circuit comprising:
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means for periodically interrupting the flow of current to or from said battery for an interruption interval of fewer than about 2 to 10 ms; means for selectively sampling the voltage of any one of said modules, during an interruption of current flow, so as to make a determination of the resistance free voltage of that module; means for comparing said resistance free voltage of the module against at least two reference voltages, to determine if said resistance free voltage is above a first predetermined level or below a second predetermined level; and means for causing an alarm indication in the event that said resistance free voltage is found to be either above said first predetermined level or below said second predetermined level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification