METHOD AND APPARATUS FOR RECHARGING A BATTERY

• US 20130207618A1
• Filed: 07/15/2011
• Published: 08/15/2013
• Est. Priority Date: 07/15/2010
• Status: Active Grant

• Current Assignee: RIOT Energy Incorporated
• Original Assignee: ZPower, LLC
• Inventors: Renken, Troy, Powers, Tim
• Granted Patent: US 9,240,696 B2
• Time in Patent Office: Days
• US Class Current: 320/155
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present invention provides a novel method for charging silver-zinc rechargeable batteries and an apparatus for practicing the charging method. The recharging apparatus includes recharging management circuitry; and one or more of a silver-zinc cell, a host device or a charging base that includes the recharging management circuitry. The recharging management circuitry provides means for regulating recharging of the silver-zinc cell, diagnostics for evaluating battery function, and safety measures that prevent damage to the apparatus caused by charging batteries composed of materials that are not suited for the charging method (e.g., non-silver-zinc batteries).

Claims

1. A method of charging a rechargeable battery having multiple voltage plateaus wherein the battery has a voltage, V_Batt, that is less than its highest voltage plateau comprising:

charging the battery with a first charging current, I₁, wherein the first charging current, I₁, is applied until the battery is charged to a voltage, V₁; and

controlling the first charging current, I₁, when the voltage of the battery is V₁, so that the voltage of the battery is maintained at V₁ with a deviation of no more than about ±

20% of V₁,

wherein voltage, V₁, is less than the voltage of a natural polarization peak, V_PP, associated with a voltage plateau, V_P, wherein V_P is greater than V_Batt, and V₁ is greater than the voltage plateau, V_P.

2. The method of claim 1, further comprising:

charging the battery with a second charging current, I₂, wherein the second charging current, I₂, is applied after the first charging current, I₁, until the battery voltage reaches a voltage, V₂, wherein the voltage, V₂, is greater than V_P, and less than V_PP; and

controlling the second charging current, I₂, when the voltage of the battery reaches the voltage, V₂, so that the voltage of the battery is maintained at V₂ with a deviation of no more than about ±

20% of V₂.

3. The method of claim 2, wherein the second charging current, I₂, is applied at least until the battery is charged to a SOC of from about 80% to about 150% of the battery'"'"'s rated capacity.

4. The method of claim 2, wherein I₁ is substantially constant until the battery is charged to a voltage, V₁.

5. The method of claim 4, wherein I₂ is substantially constant until the battery is charged to a voltage, V₂.

6. The method of claim 2, wherein the first charging current, I₁, is sufficient to charge the battery to voltage, V₁, in a period of from about 1 min to about 300 min when the battery'"'"'s initial SOC is less than 40% of its rated capacity.

12. The method of claim 2, wherein the first charging current, I₁, is controlled when the voltage of the battery is V₁, so that the voltage of the battery is maintained at V₁ with a deviation of no more than about ±

20% of V₁, for a period of from about 6 s to about 1500 s.

13. The method of claim 2, further comprising:

terminating the first charging current, I₁, after the voltage of the battery is maintained at V₁ with a deviation of no more than about ±

20% of V₁, for a period of from about 6 s to about 1200 s; and

applying the second charging current, I₂, when the first charging current, I₁, terminates.

15. The method of claim 2, wherein I₁ is greater than or equal to I₂ during the period before the battery is charged to a voltage of V₁.

16. The method of claim 15, wherein V₁ is greater than or equal to V₂.

17. The method of claim 2, wherein V_Batt is from about 50% to about 87% of the voltage, V₁.

48. The method of claim 2, wherein the method excludes counting Coulombs.

49. The method of claim 48, further comprising generating an electrical signal that indicates a soft short in the battery if V_Batt is lower than V_P for a period of more than 1 second after the battery has been charged to a voltage of V₂.

50. The method of claim 49, further comprising charging the battery with a diagnostic charge current, I_Diag, for a period of less than about 30 s, detecting the voltage of the battery, V_Batt, and terminating charging of the battery if V_Batt is about 1.65 V or less.

51. The method of claim 50, wherein I_Diag is greater than or equal to I₁.

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60. A method of charging a rechargeable battery having multiple voltage plateaus wherein the battery has an OCV that is less than about 80% of the voltage of a first sequential voltage plateau, V_P1, comprising:

charging the battery with a recovery charging current, I_recov, that is substantially constant for a period of no more than about 120 min after the voltage of charging battery reaches the first sequential voltage plateau, V_P1 that is greater than V_Batt;

charging the battery with a first charging current, I₁, wherein the first charging current, I₁, is substantially constant until the battery is charged to a voltage, V₁; and

controlling the first charging current, I₁, when the voltage of the battery reaches the voltage, V₁, so that the voltage of the battery is maintained at V₁ with a deviation of no more than about ±

20% of V₁, for a period of from about 6 s to about 900 s,

wherein voltage, V₁, is less than the voltage of the natural polarization peak, V_PP, for a voltage plateau, V_P, that is higher than V_P1, and V₁ is greater than the voltage plateau, V_P.

61. The method of claim 60, wherein I_recov is from about 5% to about 90% of I₁.

62. The method of claim 61, further comprising charging the battery with a recovery charging current, I_recov, that is substantially constant for a period of no more than about 30 min after the voltage of charging battery, V_Batt, reaches the first sequential voltage plateau, V_P1, that is greater than V_Batt, and

arresting the modulated second charge current when the battery is charged to a SOC of about 100-120% of the battery'"'"'s rated capacity;

or

arresting charge current I₂ when the charging current is below 1.0 mA, for a period of about 5 min or less;

wherein the voltages have a deviation of ±

1%, the current amperages have deviations of ±

2%, the temperature measurement accuracy has a deviation of no more than ±

5°

C., and clocked times have a deviation of ±

2%.

63. The method of claim 62, further comprising generating an electrical signal if the voltage of the battery, V_Batt, fails to reach the first sequential voltage plateau, V_P1, that is greater than V_Batt after being charged with I_recov for a period of from about 30 min to about 2 hours.

64. The method of claim 62, further comprising

charging the battery with a first charging current, I₁, wherein the first charging current, I₁, is applied until the battery is charged to a voltage, V₁;

controlling the first charging current, I₁, when the voltage of the battery is V₁, so that the voltage of the battery is maintained at V₁ with a deviation of no more than about ±

20% of V₁, wherein voltage, V₁, is less than the voltage of a natural polarization peak, V_PP, associated with a voltage plateau, V_P, wherein V_P is greater than V_Batt, and V₁ is greater than the voltage plateau, V_P; and

charging the battery with a second charging current, I₂, wherein the second charging current, I₂, is applied after the first charging current, I₁, until the battery voltage reaches a voltage, V₂, wherein the voltage, V₂, is greater than V_P, and less than V_PP; and

controlling the second charging current, I₂, when the voltage of the battery reaches the voltage, V₂, so that the voltage of the battery is maintained at V₂ with a deviation of no more than about ±

20% of V₂.

65. The method of claim 64, wherein the rechargeable battery comprises a button cell, a coin cell, a cylinder cell, or a prismatic cell.

66. The method of claim 64, further comprising:

generating an electrical signal when the second charging current, I₂, terminates.

67. The method of claim 66, further comprising:

activating a visual signal, activating an audio signal, activating a vibrational signal, or any combination thereof when the second charging current, I₂, terminates.

68. A method of charging a rechargeable battery having multiple voltage plateaus and an initial SOC of greater than 50% of its rated capacity, wherein the battery has a voltage, V_Batt, that is less than or equal to its highest voltage plateau comprising:

charging the battery with a substantially constant charging current, I₂, until the battery is charged to a voltage, V₂; and

controlling charging current, I₂, so that the voltage of the battery is maintained at V₂ with a deviation of no more than about ±

20% of V₂,

wherein voltage, V₂, is greater than the voltage of a voltage plateau, V_P, and less than the voltage of a natural polarization peak, V_PP.

69. The method of claim 68, further comprising:

terminating the charging current, I₂, when I₂ reaches I_ter, wherein I_ter is about 85% or less of I₂ during the period when the battery was being charged to V₂.

70. The method of claim 69, further comprising:

terminating the charging current, I₂, when I₂ reaches I_ter, wherein I_ter is about 75% or less of I₂ during the period when the battery was being charged to V₂.

71. The method of claim 68, wherein V₂ is about 2.0 V or less.

72. The method of claim 71, wherein the charge current, I₂, is about 6 mA when the battery is being charged to V₂.

73. The method of claim 72, further comprising terminating the charging current, I₂, when I₂ is about 4.5 mA.

74. A method of charging a rechargeable 2.0 V silver-zinc battery having an OCV of less than 1.65 V comprising:

charging the battery with first charge current, I₁, having an amperage of 10 mA or less;

clocking time once the battery is charged to a voltage of 1.90 V;

modulating the first charge current, I₁, so that the voltage of the battery is restricted to 2.03 V or less, and the first charge current, I₁, has a maximum amperage of about 10.0 mA or less;

arresting the charging of the battery with the first charge current, I₁, once 20 minutes has been clocked;

charging the battery with second charge current, I₂, wherein the charge current, I₂, is modulated so that the voltage of the battery is restricted to 2.0 V or less, and the second charge current has a maximum amperage of about 10.0 mA or less; and

arresting the modulated second charge current, I₂, when the amperage of the charge current is less than the amperage of termination current, I₂end, for a continuous period of 60 seconds or less, wherein the battery is charged to a SOC of about 80-150% of the battery'"'"'s rated capacity;

wherein

I_2end=I_Chg+I_Temp, and

I_chg is the charge compensation current, I_Temp is the temperature compensation current, I_Chg=(T₂×

I₁)/T_Chg, wherein T₂ is the integrated time in hours starting when the charge current reaches 1.90V and ending when the charge current begins to modulate to a value less than I₂; and

T_chg is the cell time constant, determined for each battery size and construction;

or

arresting charge current I₂ when the charging current is below 1.0 mA, for a period of about 5 min or less; and

the voltages have a deviation of ±

1%, the current amperages have deviations of ±

2%, the temperature measurement accuracy has a deviation of no more than ±

5°

C., and clocked times have a deviation of ±

2%.

75. The method of claim 74, further comprising measuring the temperature, wherein the temperature measurement accuracy has a deviation of ±

2°

C.

76. The method of claim 75, wherein the voltage of the battery is greater than about 1.25 V prior to charging.

77. The method of claim 75, wherein the voltage of the battery is less than about 1.25 V prior to charging.

78. The method of claim 77, further comprising:

charging the battery with a recovery charge current, I_recov, of 1.0 mA for a period of at least 30 minutes; and

arresting the recovery charge current, I_recov, when the battery is charged to a voltage of 1.60 V.

79. A method of charging a rechargeable 2.0 V silver-zinc battery having an OCV of greater than 1.65 V comprising:

charging the battery with a modulated charge current I₂, wherein the charge current I₂ is modulated so that the voltage of the battery is restricted to 2.0 V or less (e.g., 1.98 V), and the charge current has a maximum amperage, I_max, of about 6.0 mA or less;

clocking time 15 seconds after charging begins;

measuring the amperage of charge current I₂ when time is being clocked; and

arresting charge current I₂ when the amperage of I₂ is below I_2end for a period of 60 continuous seconds if the amperage of I₂ is I_max for a period of 5 or more continuous seconds when time is being clocked, wherein I_2end is the temperature dependent termination charge current level when the battery is charged to an SOC of about 100% to 150% of its rated capacity;

or

arresting charge current I₂ once the battery is charged to an SOC of about 100% to 150%, if the amperage of I₂ is I_max for a period less than 5 continuous seconds when time is being clocked, wherein the charge current is integrated until 50% of the battery'"'"'s rated capacity is counted;

or

arresting charge current I₂ when the amperage of I₂ is below 1.0 mA for a period of about 5 min or less after the clocking time is complete.

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