Patent US5372898A successfully refreshed from Google Patents.
US5372898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Universal inexpensive battery state-of-charge indicator
Assignee: United States Department of the Army
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Filing: 1994-02-17
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Granted: 1994-12-13
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Expires: 2014-02-17
Abstract
Abstract A discharge level monitor for a battery. The current flowing from the monred battery is passed through a sensing resistor. The voltage across the resistor is amplified and integrated over time and the result of the integration is stored in a capacitor. The capacitor is discharged by a switch controlled by a logic circuit, whenever a threshold voltage is achieved. The cycle is repeated each time one coulomb capacity is removed from the battery. A counting circuit counts the number of charge/discharge cycles of the capacitor to produce a count which is representative of the amount of energy dissipated and therefore indirectly of the amount of energy remaining in the battery system.
Inventors
- 👤 Terrill Atwater
- 👤 Richard M. Dratler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:35
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/42; H01M10/48; G; G01; G01R; G01R29/00; G01R29/24; G01R31/00; G01R31/36; G01R31/382; G01R31/3828; G01R31/3644; G01R31/3648; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10S; Y10S320/00; Y10S320/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
97 words
A battery system monitor, comprising: a current sensing means for sensing current flowing from a battery to a load; a current integrator for measuring the amount of electrical energy flowing from the battery and for producing an output indicative of a predetermined amount of electrical charge having been discharged from the battery; a counter circuit for counting the output of the current integrator and for producing a counter output indicative of a discharge level of the battery; and a display coupled to the counter circuit for providing a visual indication of the discharge level of the battery.
Claim 2
Dependent Claim
97 words
A battery system monitor, comprising: a current sensing means for sensing current flowing from a battery to a load; a current integrator for measuring the amount of electrical energy flowing from the battery and for producing an output indicative of a predetermined amount of electrical charge having been discharged from the battery; a counter circuit for counting the output of the current integrator and for producing a counter output indicative of a discharge level of the battery; and a display coupled to the counter circuit for providing a visual indication of the discharge level of the battery.
Claim 3
Dependent Claim
23 words
The battery system monitor of claim 1, wherein the current sensing means is tuned to compensate for variations in temperature and discharge rate.
Claim 4
Dependent Claim
30 words
The battery system monitor of claim 2, wherein the current sensing means is configured such that changes in temperature and discharge rate cause the current sensing means to time itself.
Claim 5
Dependent Claim
26 words
The battery system monitor of claim 2, wherein the current sensing means is tuned such that a threshold wattage represents a predetermined amount of capacity removed.
Claim 6
Dependent Claim
22 words
The battery system monitor of claim 1, wherein the current sensing means comprises a current sensing resistor of a very low value.
Claim 7
Dependent Claim
18 words
The battery system monitor of claim 5, wherein the current sensing resistor has a value below one ohm.
Claim 8
Dependent Claim
41 words
The battery system monitor of claim 5, wherein the current integrator is an operational amplifier and including a storage capacitor, the operational amplifier being effective to charge the capacitor at a rate approximately proportional to the current flowing through the resistor.
Claim 9
Dependent Claim
37 words
The battery system monitor of claim 7, wherein the current integrator further includes a differential amplifier and the differential amplifier is operative to discharge the capacitor when a predetermined amount of electrical energy has been stored therein.
Claim 10
Dependent Claim
46 words
The battery system monitor of claim 7, wherein the counter circuit includes a flip-flop circuit which is coupled to the counter circuit to assure that the counter circuit does not accidentally reset when a battery voltage associated with the battery has dropped below a predetermined value.
Claim 11
Dependent Claim
30 words
The battery system monitor of claim 7, wherein the display comprises a plurality of diodes and the state of the diodes is indicative of the discharge level of the battery.
Claim 12
Dependent Claim
15 words
The battery system monitor of claim 10, further including means for selectively enabling the display.
Claim 13
Dependent Claim
40 words
The battery system monitor of claim 7, further including switch means connected across input terminals of the battery system monitor and configured to be set to a conductive state to discharge the battery prior to the battery being disposed of.
Claim 14
Dependent Claim
63 words
The battery system monitor of claim 7, wherein the battery includes first and second batteries and including means of enabling connection of the first and second batteries to a load in either a series or a parallel configuration and wherein the current flowing through the first battery is monitored and the discharge level of the first battery is assumed for the second battery.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-12 | 1998-06-13 | 1998-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-12 | 2002-06-13 | 2002-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-12 | 2006-06-13 | 2006-12-13 | $7700.00 | Window Closed / Lapsed |