Battery testing device and battery testing method
Contents
1. THREE HOURS 100 eee ir 50 START OF HEATING UP TO 150 C WHEN BATTERY CAPACITY REACHES PREDETERMINED CAPACITY SETTING TEMPERATURE OF TEMPERATURE ADJUSTMENT DEVICE NORMAL TEST TEMPERATURE IS 50 0 1 2 3 TESTING TIME HOURS U S Patent Jul 24 2012 Sheet 11 of 12 US 8 228 039 B2 Fig 11 UNUSED BATTERY 75 DETERIORATION 1 1 50 DETERIORATION DETERIORATION DEGREE OF DETERIORATION OF BATTERY CAPACITY AFTER ONE YEAR OF CYCLE TEST NORMAL TEST TEMPERATURE IS 50 C 5 0 i ZERO ONE TWO YEARS YEAR YEARS TESTING TIME U S Patent Jul 24 2012 Sheet 12 of 12 US 8 228 039 B2 Fig 12 200 Pt BATTERY TEMPERATURE BATTERY N TEMPERATURE BATTERY NNG BATTERY THREE HOURS 50 STARTS HEATING UP 150 C WHEN BATTERY CAPACITY REACHES A PREDETERMINED CAPACITY AND BATTERY VOLTAGE V NORMAL TEST TEMPERATURE IS 50 C Q O O 0 1 2 3 TESTING TIME HOURS SETT NG TEMPERATURE OF TEMPERATURE ADJUSTMENT DEVICE C US 8 228 039 B2 1 BATTERY TESTING DEVICE AND BATTERY TESTING METHOD BACKGROUND OF THE INVENTION 1 Field of the Invention The present invention relates to a battery testing device and a battery testing method for testing a chargeable secondary battery by applying a load by performing charging using a charging means to charge the secondary batt2. It is preferable that the temperature adjustment means makes an adjustment to hold the temperature ofthe secondary battery at 150 C for three hours when the battery capacity of the secondary battery reaches 7596 5096 or 2596 ofthe battery capacity of an unused secondary battery of the same type as the secondary battery by a repeat ofthe discharge and charge of the secondary battery Thereby the temperature of the secondary battery is held at 150 C for three hours when the battery capacity reaches 7596 5096 or 2596 of the battery capacity of the unused secondary battery by a repeat of the discharge and charge of the secondary battery Hence the state of the secondary battery under such an environment can be evaluated It is indispensable that the temperature adjustment means determines whether the temperature of the secondary battery rises to 160 C or more while holding the temperature of the secondary battery at 150 C for three hours and displays the result of this determination on a external device Thereby for the secondary battery which rises to 160 C or higher tem perature state because of the sudden start of a thermo run away due to the start of thermal decomposition of the battery materials at around 150 C it can be decided whether thermal decomposition started and the determination result can be displayed whereby whether the secondary battery has risen to 160 C or more can be evaluated To achieve the above object a
3. Here when the battery capacity of the lithium ion battery 2 deteriorate to 75 50 or 25 of the charged state of the battery capacity in an unused state 10096 the temperature adjustment device 5 increases the temperature of the lithium ion battery 2 from about 50 C which is the normal test temperature to about 150 C and then holds the tempera ture at about 150 for three hours While holding the temperature of the lithium ion battery 2 at about 150 C for three hours the temperature adjustment device 5 judges whether the temperature of the lithium ion battery 2 increases to about 160 C or more using the ther mister 6 The temperature adjustment device 5 distinguishes a lithium ion battery 2 of which temperature is increased to about 160 C or more as an NG battery which is not appro priate to be used for a portable telephone 10 and displays this information on the temperature display device 7 and distin guishes a lithium ion battery 2 of which temperature does not increase to about 160 C or more that is increases to a temperature less than about 160 C as an OK battery which is appropriate to be used for a portable telephone 10 and displays this information on the temperature display device 7 Thereby a non defective battery OK battery of which temperature does not increases to about 160 C or more even if the battery heats up to about 150 C can be selected from the lithium ion batteries 2 of which capacity
4. PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described with reference to the accompanying drawings In the description of the drawings the same composing ele ments are denoted with the same symbols for which redun dant description is omitted First a configuration of a battery testing device 100 accord ing to the present embodiment will be described with refer ence to FIG 3 FIG 3 is a diagram depicting the configuration of the battery testing device 100 The battery testing device 100 is a device for enabling the accurate testing of the per formance ofa lithium ion battery 2 secondary battery being connected for charging by performing the charge using an AC adapter 1 charging module for charging the lithium ion battery 2 and the discharge of the lithium ion battery 2 to apply load The AC adapter 1 is connected to the portable telephone 10 on the one hand and is connected to a commer cial power supply 9 on the other hand The battery testing device 100 has a charge control circuit 3 input control mod ule a radio circuit 4 output control module and a tempera ture adjustment device 5 temperature adjustment module The lithium ion battery 2 is a chargeable secondary battery Instead ofthe lithium ion battery 2 a lithium polymer battery may be used as a chargeable secondary battery The charge control circuit 3 is a circuit to control the DC power P2 input power which is input to the l
5. battery testing method according to the present invention is a battery testing method which can charge a chargeable secondary battery by using charging means for charging the secondary battery the method having an input control step of controlling the input power which the charging means inputs to the secondary battery and an output control step of controlling the output power which is output from the secondary battery and dis charging the secondary battery wherein when the secondary battery reaches a fully charged state the discharge of the 5 20 40 45 55 4 secondary battery is started in the output control step while stopping the charge ofthe secondary battery using the charg ing means in the input control step and when the secondary battery reaches a predetermined charged state the charge of the secondary battery using the charging means is started in the input control step while stopping the discharge of the secondary battery in the output control step In the battery testing method according to the present invention when the secondary battery reaches the fully charged state the discharge of the secondary battery is started in the output control step while stopping the charge of the secondary battery using the charging means in the input con trol step and when the secondary battery reaches a predeter mined fully charged state the charge ofthe secondary battery using the charging means is started in the inp
6. circuit 3 stops charging the lithium ion battery 2 using the AC adapter 1 0 5 40 45 50 55 65 10 while the radio circuit 4 starts discharging the lithium ion battery 2 and when the lithium ion battery 2 reaches pre determined charged state the radio circuit 4 stops discharging the lithium battery 2 while the charge control circuit 3 starts charging the lithium ion battery 2 using the AC adapter 1 Thereby when the lithium ion battery 2 reaches the fully charged state a discharge of the lithium ion battery 2 starts and when the lithium ion battery 2 reaches a predetermined charged state charge of the lithium ion battery 2 starts and this cycle is repeated Therefore the performance of the lithium ion battery 2 in a portable telephone 10 being con nected for charging can be more accurately evaluated by applying a load of charging and discharging the lithium ion battery 2 conforming to the actual way of use such as using the portable phone 10 while being charged via the AC adapter 1 for example Thereby a test to evaluate performance using the lithium ion battery 2 in this state becomes possible Also input power control and output power control for the lithium ion battery 2 at a temperature adjusted by the temperature adjustment device 5 are performed Hence the influence of temperature on the performance of the lithium ion battery 2 can be accurately evaluated Thereby a test to evaluate per forma
7. deteriorated to 75 50 or 25 of the battery capacity in an unused state Inthe case ofa lithium ion battery 2 having a battery capacity in an unused state 10096 heating to about 150 C is per formed immediately and in the case ofa lithium ion battery 2 of which battery capacity is 7596 or less ofthe battery capac ity in an unused state heating is started when the battery capacity becomes a predetermined value Concerning the thermal stability of the lithium 10n battery 2 a current lithium ion battery sometimes becomes about a 160 C orhighertemperature state when heated to about 150 C since the thermal decomposition of the battery materials starts and thermo runaway suddenly begins Therefore it is a critical safety confirmation for a lithium ion battery 2 to check that this thermal decomposition and thermo runaway is not generated even if the battery heats up to about 150 C that 15 a temperature threshold at which thermal decomposition and thermo runaway occurs does not drop A case of the lithium ion battery 2 becoming about 150 C is a case of internal failure such as a short occurring to the lithium ion battery 2 case of the lithium ion battery 2 externally being heated dropping into hot tempura oil or being left in a car on a hot summer day As described above according to the battery testing device 100 of the present invention if the lithium ion battery 2 reaches a fully charged state the charge control
8. in several steps from 5 to 10095 are provided and testing 15 performed using each of these values As FIG 7 shows the degree of capacity dete rioration that is the deterioration amount of the lithium ion battery 2 increases as the depth of discharge that is the discharge amount decreases that is as the value becomes closer to 596 Therefore a lithium ion battery 2 when the cycle test is performed with the depth of discharge as 596 that is discharge up to 95 of the battery capacity fully charged state can be defined as a lithium ion battery 2 having a worst value with which the capacity deterioration degree becomes the worst Now the relationship of the battery voltage Vb V of the lithium ion battery 2 and the charge ratio that is the charged state Qb 96 will be described with reference to FIG 8 FIG 8 isa graph depicting a relationship of the battery voltage Vb 0 5 20 30 40 45 55 60 8 V and the charge ratio that is the charged state Ob 96 of the lithium ion battery 2 where the abscissa indicates the operation time and the ordinate indicates the battery voltage Vb and the charge ratio Qb As FIG 8 shows when a voltage Vb e g about 4 0 V corresponding to the 9596 Qb charge ratio that is 5 DOD is determined this voltage Vb becomes the recharge start voltage Vstart Now the change of degree of the drop of battery capacity that is the capacity deterioration of
9. starts discharging the secondary battery while the input control means stops charging the secondary battery using the charg ing means and when the secondary battery reaches a prede termined charged state the input control means starts charg ing the secondary battery using the charging means while the output control means stops discharging the secondary battery Inthe battery testing device according to the present inven tion when the secondary battery reaches the fully charged state the output control means starts discharging the second ary battery while the input control means stops charging the secondary battery using the charging means and when the secondary battery reaches a predetermined charged state the input control means starts charging the secondary battery using the charging means while the output control means stops discharging the secondary battery Thereby the dis charge of the secondary battery starts when the secondary battery reaches the fully charged state and the charge of the secondary battery starts when the secondary battery reaches the predetermined charged state and this cycle is repeated Therefore load is applied to a portable telephone by perform ing the charge and discharge of the secondary battery con forming to the actual way of use of the portable telephone such as using the portable telephone while being connected to such charging means as an AC adapter for charging thereby the performance of the sec
10. the battery due to the temperature change when the cycle test to repeat charge and discharge of the lithium ion battery 2 will be described with reference to FIG 9 FIG 9 is a graph depicting the change of degree of drop of battery capacity due to temperature change when the cyclic test to repeat charge and recharge is per formed for one year where the abscissa indicates the tem perature of the lithium ion battery 2 and the ordinate indi cates the deterioration degree 90 Here 596 DOD is a test condition and testing is performed holding the temperature to about 20 C to about 30 to about 40 C and to about 50 C respectively As FIG 9 shows when the temperature is increased to about 20 C to about 30 C and to about 40 C respectively the capacity deterioration of the battery progresses little but in the case of about 50 the capacity deterioration of the battery suddenly progresses Hence the capacity deterioration of the battery can rapidly progress by testing the lithium ion battery 2 with holding the temperature to about 50 C Now the temperature change of the lithium ion battery 2 due to the change of test time when the cycle test to repeat charge and discharge ofthe lithium ion battery 2 is performed will be described with reference to FIG 10 FIG 10 is a graph depicting the temperature change of the lithium ion battery 2 due to the change of test time when the cycle test to repeat charge and discharge i
11. 0 gt 1 r r 0 ad PL a p x e Seu mee SEE um 2 a HEJSA 7 i ab x 0 3 5 45 o o a 3007 90910 ADYVHO 11949 0 9 614 U S Patent Jul 24 2012 Sheet 7 of 12 US 8 228 039 B2 DEGREE OF DETERIORATION OF BATTERY CAPACITY AFTER ONE YEAR OF CYCLE TESTING S0 DETERIORATION T DETERIORATION AMOUN T AMOUN DETERIORATION E 2 2 2 2 2 22 2222222 2d 2222 22222222222222222222 2 2224 TEST 50 C 6 120 MINUTES MINUTES 596 10094 OPERATION FREQUENCY DEPTH OF DISCHARGE DOD 96 U S Patent Jul 24 2012 Sheet 8 of 12 US 8 228 039 B2 Fig 8 CHARGE DISCHARGE S M ee Vb e Vstart 0 gt OPERATION TIME OO ee 7 ab x Ip ar EM OPERATION TIME U S Patent Jul 24 2012 Sheet 9 of 12 US 8 228 039 B2 Fig 9 DEGREE OF DETERIORATION OF BATTERY CAPACITY AFTER ONE YEAR OF CYCLE TEST 96 20 30 40 50 BATTERY TEMPERATURE U S Patent Jul 24 2012 Sheet 10 of 12 US 8 228 039 B2 Fig 10 200
12. 36600 for example However in this conventional battery performance test the actual case ofusing a portable telephone while being charged by being connected to an AC adapter as mentioned above is not considered therefore a better result than actual perfor 20 25 30 35 40 45 50 55 60 65 2 mance is exhibited in this conventional battery performance test and the performance of the secondary battery cannot be evaluated accurately SUMMARY OF THE INVENTION With the foregoing in view it is an object of the present invention to provide a battery testing device and battery test ing method for testing the performance of the secondary battery in a portable telephone being connected for charging by applying a load of performing charge and discharge of the secondary battery conforming to the actual way of use of the portable telephone To achieve the above object a battery test device according to the present invention is a battery testing device which can charge a chargeable secondary battery by using charging means for charging the secondary battery the device com prising input control means for controlling the input power which the charging means inputs to the secondary battery and output control means for controlling the output power which is output from the secondary battery and discharging the secondary battery wherein when the secondary battery reaches a fully charged state the output control means
13. 84 Mar 24 2005 pp 298 305 T Guena et al How Depth of Discharge Affects the Cycle Life of Lithium Metal Polymer Batteries Annual International Telecom munications Energy Conference 28 IEEE XP31020314 Sep 1 2006 pp 1 8 Masahiro Ichimura et al Synergistic Effect of Charge Discharge Cycle and Storage in Degradation of Lithium ion Batteries for Mobile Phones Telecommunications Conference XP31063288 Sep 1 2005 pp 245 250 Isidor Buchmann Choosing a Battery that will Last Cycle Life of Various Battery Systems Battery Conference on Applications and Advances IEEE XP10352795 Jan 12 1999 pp 365 368 Kazuhiko Takeno et al Quick testing of batteries in lithium ion battery packs with impedance measuring technology Journal of Power Sources vol 128 XP4493641 Mar 29 2004 pp 67 75 Office Action issued Jan 27 2011 in China Patent Application No 200810185663 X with English translation Japanese Office Action issued Oct 25 2011 in Patent Application No 2007 327661 with English language translation Office Action issued Jun 29 2011 in Korean Patent Application No 10 2008 0127801 with English language translation Chinese Office Action issued Feb 13 2012 in Patent Application No 200810185663 X with English language translation Korean Office Action mailed Apr 20 2012 in Japanese Patent Appli cation No 10 2008 0127801 with English translation Korean Office Action mailed
14. Mar 31 2012 in Japanese Patent Appli cation No 10 2008 0127801 with corrected English translation cited by examiner US 8 228 039 B2 Sheet 1 of 12 Jul 24 2012 U S Patent 1 09 001 AYALIVE LINDO lOHINOO d3ldvav Ov 761 4 U S Patent Jul 24 2012 Sheet 2 of 12 US 8 228 039 B2 Fig 2 BATTERY VOLTAGE V CHARGE CHARGE DISCHARGE S PO T bR 10 MINUTES 6 MINUTES 10 MINUTES OPERATION TIME US 8 228 039 B2 Sheet 3 of 12 Jul 24 2012 U S Patent 16 LINDAIO 0729 21001130 3030 77 38011 30 3 310 03 31 98 r 1 1 1 1 1 1 1 1 1 001000 ov big US 8 228 039 B2 Sheet 4 of 12 Jul 24 2012 U S Patent 31360 23200130 32 0 2081303 210 0 US 8 228 039 B2 Sheet 5 of 12 Jul 24 2012 U S Patent A Ed CA NOLL93130 39VLTOA 003130 0 TOULNOD 440 NO 30 INVISNOO 39HVHO G DI4 US 8 228 039 B2 Sheet 6 of 12 Jul 24 2012 U S Patent NOLLVH3dO I 1 T H 5 a I I l 1 i I 0 NE ae L 4
15. US008228039B2 a2 United States Patent Patent No US 8 228 039 B2 Takeno et al 45 Date of Patent Jul 24 2012 54 BATTERY TESTING DEVICE AND BATTERY A TESTING METHOD JP 2003 9406 1 2003 2003 282150 10 2003 75 Inventors Kazuhiko Takeno Yokohama JP IP 2007 292654 11 2007 Takayuki Kanai Yokohama JP OTHER PUBLICATIONS Haruo Uemura Kita ku JP 73 Assignee NTT DoCoMo Inc Tokyo JP Notice Subject to any disclaimer the term of this patent is extended or adjusted under 35 U S C 154 b by 439 days 21 Appl 12 335 944 22 Filed Dec 16 2008 65 Prior Publication Data US 2009 0160403 A1 Jun 25 2009 30 Foreign Application Priority Data De 19 2007 GE kiz 2007 327661 51 Int Cl H02J 7 00 2006 01 52 USELESS RAA 320 136 58 Field of Classification Search 320 124 320 127 136 324 427 See application file for complete search history 56 References Cited U S PATENT DOCUMENTS 2007 0145949 Al 6 2007 Matsushima et al 320 132 FOREIGN PATENT DOCUMENTS CN 200972879 Y 11 2007 JP 8 136600 5 1996 Matsushima et al Residual Capacity Estimation of Stationary Lithium ion Secondary Cells in Telecommunications Systems Using a Brief Discharge 28th Annual International Telecommunications Energy Conference pp 1 7 Sep 2006 R Dueber Tests Prove the Safety of Silver Zinc Battery Technology over Lithium Ion pp 1 9
16. ay The 3rd International Sympo sium on Large Lithium Ion Battery Technology and Application pp 1 29 May 2007 Kozuka et al Development of on line battery testing technology 19th International Telecommunications Energy Conference pp 397 402 Oct 1997 Tsujikawa et al Development of VRLA battery capacity estimation system 29th International Telecommunications Energy Conference pp 788 793 Oct 2007 BT2000 Custom Designed Multi Channel Battery Testing System available at http web archive org web 20070508072210 http arbin com Download products bt2000 pdf on Oct 24 2007 Arbin 010 MITS Pro 4 0 BT2000 User Manual available at http web archive org web 20070508082125 http arbin com Download support MITSPro4 0 BT2000 pdf on Oct 24 2007 Guena et al How Depth of Discharge Affects the Cycle Life of Lithium Metal Polymer Batteries 28th Annual International Tele communications Energy Conference 2006 INTELEC 06 pp 1 8 Sep 2006 Extended European Search Report issued Nov 4 2010 in Patent Application No 08171911 4 T L Chern et al The Research of Smart Li ion Battery Manage ment System Second IEEE Conference on Industrial Electronics and Applications XP31137752 May 1 2007 pp 2273 2277 Kazuhiko Takeno et al Influence of cycle capacity deterioration and storage capacity deterioration on Li ion batteries used in mobile phones Journal of Power Sources vol 142 No 1 2 XP48129
17. dated Jul 2007 Continued Primary Examiner Melissa Koval Assistant Examiner Daniel Miller 74 Attorney Agent or Firm Oblon McClelland Maier amp Neustadt L L P Spivak 57 ABSTRACT The present invention applies load to a portable telephone by charging and discharging a secondary battery conforming to the actual way of use of the portable telephone so that the performance ofthe secondary battery in a portable telephone connected for charging can be accurately tested A battery testing device of the present invention has a charge control circuit for controlling input power which is input to a lithium ion battery via an AC adapter and a radio circuit for control ling output power which is output from the lithium ion battery and discharging the lithium ion battery wherein when the lithium ion battery reaches a fully charged state the radio circuit starts discharging while the charge control circuit stops charge of the lithium ion battery using the AC adapter and when the lithium ion battery reaches a predetermined charged state the charge control circuit starts charge of the lithium ion battery using the AC adapter while the radio circuit stops discharge of the lithium battery 6 Claims 12 Drawing Sheets P3 V3 x13 US 8 228 039 B2 Page2 OTHER PUBLICATIONS Kim et al Analysis of Heat Dissipation in Li Ion Cells amp Modules for Modeling of Thermal Runaw
18. erature of about 150 C for a period of about 3 hours when a battery capacity of the secondary battery falls below a threshold judging whether the temperature of the secondary battery rises to 160 C or more while performing adjustment to hold the temperature of the secondary battery at the second temperature and displaying a result of the judg ment on an external device wherein the controlling an input power and controlling an output power are cyclically performed in a plurality of charge discharge cycles and each charge discharge cycle includes when the secondary battery reaches a fully charged state discharging the secondary battery is started in the controlling an output power and the controlling an input power is stopped and when the secondary battery reaches a predetermined charged state charging the secondary battery using the charging module is started in the controlling an input power and the controlling an output power is stopped
19. erature adjusted by the temperature adjustment device 4 The battery testing device according to claim 3 wherein the input control module controls the input power which is input in use of the charging module to the secondary battery held at the first temperature as adjusted by the temperature adjustment device and theoutput control module discharges the secondary battery by controlling the output power that is output from the secondary battery held at the first temperature as adjusted by the temperature adjustment device 5 The battery testing device according to claim 4 wherein the temperature adjustment device makes the adjustment to hold the temperature of the secondary battery at the second temperature for three hours when the battery capacity of the secondary battery reaches 7596 5096 or 2596 of a battery capacity of an unused secondary battery of the same type as 5 20 25 30 12 the secondary battery by the cyclically performed plurality of charge discharge cycles of the secondary battery 6 A battery testing method that charges chargeable sec ondary battery by using a charging module comprising controlling an input power that the charging module inputs to the secondary battery and controlling an output power that is output from the second ary battery and discharges the secondary battery and increasing a temperature of the secondary battery from a first temperature of about 50 to a second temp
20. ery and discharg ing of this secondary battery 2 Related Background Art As a multimedia function e g transmission reception of mail and viewing TV of portable telephones there is a format to use a portable telephone while simultaneously being recharged by connecting a charger that is and AC adapter as shown in FIG 1 in order to enable lengthy use of the portable telephone FIG 1 is ablock diagram depicting a state when an AC adapter 91 is connected to a portable telephone 90 The AC adapter 91 is also connected to a commercial power supply 99 A portable telephone 90 encloses a lithium ion battery 92 as a secondary battery pack a charge control circuit 93 and a radio circuit 94 as a load device to discharge the battery in many cases A tendency of a lithium ion battery 92 enclosed in many electronic equipment including portable telephones 90 which occurs depending on the state of use of the electronic equipment e g charging frequency number of times of use ambient temperature during uses is that the battery capacity decreases that is capacity deterioration of the battery or the thermal stability of the materials inside the battery that is active materials drops the thermo runaway easily occurs when the temperature inside the battery becomes high For example in a case of using a portable telephone 90 while being charged by being connected to an AC adapter as mentioned above charge and discharge are repeated in a hig
21. g adjustment to hold the tem perature of the secondary battery at the second tempera ture and displays a result ofthe judgment on an external device wherein the input control module and the output control module are configured to cyclically perform a plurality of charge discharge cycles and each charge discharge cycle includes when the secondary battery reaches a fully charged state the output control module starts discharging the sec ondary battery while the input control module stops charging the secondary battery using the charging module and when the secondary battery reaches a predetermined charged state the input control module starts charging US 8 228 039 B2 11 the secondary battery using the charging module while the output control module stops discharging the secondary battery 2 The battery testing device according to claim 1 wherein the output control module discharges the secondary battery until reaching a state of 95 of the battery capacity in the fully charged state when the secondary battery reaches the fully charged state 3 The battery testing device according to claim 1 wherein the input control module controls the input power that is input to the secondary battery at the temperature adjusted by the temperature adjustment device using the charging module and theoutput control module discharges the secondary battery by controlling the output power that is output from the secondary battery at the temp
22. gram depicting a configuration of a battery testing device FIG 4 is a graph describing the change of each index in a battery performance test FIG 5 15 a circuit diagram depicting a concrete circuit configuration to implement a configuration of a battery test ing device FIG 6 is a graph depicting the changes of each index according to a concrete circuit configuration to implement the configuration of a battery testing device FIG 7 is a graph depicting the degree ofthe drop of battery capacity when the cycle test to repeat charge and discharge is performed FIG 8 is a graph depicting the relationship between the battery voltage Vb and the charge ratio Qb of a lithium ion battery FIG 9 is graph depicting the change of degree ofthe drop of battery capacity based on the temperature change when the cycle test to repeat charge and discharge is performed FIG 10 is a graph depicting the temperature change ofthe lithium ion battery based on the change oftest time when the cycle test to repeat charge and discharge is performed US 8 228 039 B2 5 11 isa graph depicting the change of battery capacity of the lithium ion battery based on the change of test time when the cycle test to repeat charge and discharge is per formed and FIG 12 is a graph depicting the temperature change of the lithium ion battery based on the change oftest time when the cycle test to repeat charge and discharge is performed DESCRIPTION OF THE
23. he temperature adjustment means makes an adjustment to hold the temperature ofthe secondary battery at 50 C the input control means controls the input power which is input in use of the charging means to the secondary battery at 50 C adjusted by the temperature adjustment means and the output control means discharges the secondary battery by controlling the output power which is output from the secondary battery at 50 C adjusted by the temperature adjustment means Thereby input power control and output power control are performed for the secondary battery at 50 C adjusted by the temperature adjustment means Hence the influence of 50 C a relatively high tem perature on the performance of the secondary battery can be more accurately evaluated It is preferable that the temperature adjustment means makes an adjustment to hold the temperature ofthe secondary battery at 150 C for three hours when the battery capacity of the secondary battery reaches a predetermined capacity by a repeat ofthe discharge of the secondary battery by the output control means and the charge of the secondary battery using the charging means by the input control means Thereby the temperature of the secondary battery is held at 150 C for three hours when the battery capacity reaches a predeter mined capacity by a repeat of the discharge and charge of the secondary battery Hence the state of the secondary battery under such an environment can be evaluated
24. hly charged state where the voltage is in about a 4 0 V to 4 2 V range as shown in FIG 2 so the charge amount required for a 10096 chargeable amount gradually decreases and the capacity deterioration of the lithium ion battery 92 as the secondary battery progresses FIG 2 is a graph showing an example of the change of battery voltage when charge and discharge are repeated in the lithium ion battery 92 being connected for charging In the case of using the equipment while being connected for charging like this when charging completes the power required for activating the above men tioned radio circuit 94 is discharged from the above men tioned radio circuit is discharged from the lithium ion battery 92 to the radio circuit 94 As a result battery voltage drops and charge is restarted when the battery voltage reaches the recharge start voltage Vstart e g about 4 0 V in FIG 2 and this cycle is repeated Conventionally a test to evaluate the performance of the secondary battery such as the degree of the above mentioned capacity deterioration of a secondary battery a complete dis charge that is a 10096 discharge ofthe secondary battery and a complete charge that is a 10096 charge are regarded as one cycle and a test to evaluate the performance of the secondary battery is performed by repeating this cycle This battery performance test is performed by using a test device disclosed in Japanese Patent Application Laid Open No H8 1
25. ich is thesametype and same model ofthis lithium ion battery 2 and is not used new product and same type the temperature adjustment device 5 makes an adjustment so that the tempera ture of the lithium ion battery 2 is held at about 150 C for three hours As FIG 11 shows if about half a year has elapsed from the unused battery state 10096 battery capacity then the battery capacity deteriorates to 7596 of the battery capacity in the fully charged state then if about one year has elapsed from the US 8 228 039 B2 9 unused battery state the battery capacity deteriorates to 5096 of the battery capacity in the fully charged state and if about two years have elapsed from the unused battery state the battery capacity deteriorates to 2596 ofthe battery capacity in the fully charged state This means that the degree of capacity deterioration of the battery can be adjusted by adjusting the test time Now the temperature change of the lithium ion battery 2 due to the change of test time when the cycle test to repeat charge and discharge of the lithium ion battery 2 will be described with reference to FIG 12 FIG 12 is a graph depict ing a temperature change of the lithium ion battery 2 due to the change of test time when the cycle test to repeat charge and discharge is performed where the abscissa indicates the test time and the ordinate indicates the setting temperature by the temperature adjustment device 5 and the battery voltage
26. index such as powers P1 to P3 battery voltage Vb V ofthe lithium ion battery 2 and charge ratio that is the charged state Qb 96 shown in FIG 3 will be described with reference to FIG 4 FIG 4 is a graph depicting the change of each index operation waveform where the abscissa indicates the operation time and the ordi nate indicates the magnitude of each index The battery volt age Vstart in FIG 4 is a voltage with which the recharge ofthe lithium ion battery 2 is started the battery voltage Vstop is a maximum voltage when the lithium ion battery 2 reaches the fully charged state and power Pstop is the charge stop power to be a timing of the termination of charging the lithium ion battery 2 First the lithium ion battery 2 is discharged immediately after the lithium ion battery 2 reaches the fully charged state timing Ta to be a charge state which is 9596 of the battery capacity in the fully charged state that is the charge capacity timing Tb In other words after this discharge period tim ing Ta to Tb 596 of the battery capacity has been discharged Qb 95 from the fully charged state Qb 100 Dis charging the fully charged state by 5 is defined as DOD 5 DOD Depth Of Discharge Concerning the charging discharging conditions of the lithium ion battery 2 the recharge start voltage Vstart is about 4 0 V corresponds to 9596 battery capacity the maximum voltage Vstop in the constant current CC period maximu
27. ithium ion battery 2 from the commercial power supply 9 via the AC adapter 1 The control system for DC power P2 by the charge control circuit 3 will be described in detail later The charge control circuit 3 inputs DC power P2 out ofthe DC power P1 which is output from the AC adapter 1 to the lithium ion battery 2 The radio circuit 4 is a circuit that functions as a load device which controls the output power P3 being output from the lithium ion battery 2 and discharges the lithium ion bat tery 2 The control system for the output power P3 by the radio circuit 4 will be described in details later Instead of the radio circuit 4 a circuit to implement the adjustment of load fluc tuation that is a circuit having resistance load may be used The temperature adjustment device 5 is a device for per forming temperature adjustment including the cooling func tion and heating function to hold the temperature operation temperature of the lithium ion battery 2 at a predetermined arbitrary temperature The temperature adjustment device 5 has a thermister 6 and a temperature display device 7 The thermister 6 is a device for measuring the temperature of the lithium ion battery 2 The temperature display device 7 is a device for displaying the temperature of the lithium ion bat tery 2 measured by the thermister 6 Now power control methods by the charge control circuit 3 and the radio circuit 4 will be described respectively with reference t
28. m voltage when the battery reaches fully charged state accord ing to the charging method for the lithium ion battery 2 two step charging by constant current CC constant voltage CV is about 4 2 V the charge termination power Pstop at the end of the constant voltage CV period is about 0 21 W 54 2 Vx50 mA where 50 mA is a termination current of a general battery in the constant voltage CV period When the voltage ofthe lithium ion battery 2 drops to about 4 0 V which is the recharge start voltage Vstart timing Tb the recharge control circuit 3 controls the DC power P2 which is input to the lithium ion battery 2 via the AC adapter 1 and starts charging the lithium ion battery 2 Since the voltage ofthe lithium ion battery 2 increases from about 4 0 V to 4 2 V in the constant current CC period the DC power P2 value which is input to the lithium ion battery 2 also increases When the voltage ofthe lithium ion battery 2 is increased to about 4 2 V the constant current CC period shifts to the constant voltage CV period and the charge control to input DC power P2 to the lithium ion battery 2 is performed while constantly maintaining the voltage to about 4 2 V At this time the DC power P2 decreases at a predetermined gradient and the charge control stops when the DC power P2 reaches the US 8 228 039 B2 7 charge termination power Pstop 0 21 W timing Tc Here the charge control circuit 3 sends the discharge start signal Sdi
29. nce using the lithium ion battery 2 in this state can be performed In the actual operation of the portable telephone 10 the charge period and discharge period overlap but in the present embodiment the charge period and discharge period are separated and modeled to be equivalent as mentioned above In other words in the lithium ion battery 2 the charge mode and discharge mode are separated and the lithium ion bat tery 2 is operated only in one of these modes at a time so the operation pattern is specified such that the charge mode and discharge mode are separated What is claimed is 1 A battery testing device that charges a chargeable sec ondary battery by using a charging module comprising an input control module that controls an input power that the charging module inputs to the secondary battery anoutput control module that controls an output power that is output from the secondary battery and discharges the secondary battery a temperature adjustment device configured to heat and cool the secondary battery the temperature adjustment device configured to increase the temperature of the secondary battery from a first temperature of about 50 C to a second temperature of about 150 C for a period of about 3 hours when a battery capacity of the second ary battery falls below a threshold wherein the temperature adjustment device judges whether the temperature ofthe secondary battery rises to 160 C or more while performin
30. nts I1 to I3 A the voltages V1 and 26 V the battery voltage Vb V of the lithium ion battery 2 and the charge ratio that is the charged state Qb 96 shown in FIG 5 will be described with reference to FIG 6 FIG 6 is a graph for describing the change of each index operation waveform where the abscissa indicates the operation time and the ordinate indi cates the magnitude of each index Here the battery voltage Vstart in FIG 6 is a voltage at which the recharge of the lithium ion battery 2 is started and the battery voltage Vstop is the maximum voltage at which the lithium ion battery 2 reaches the fully charged state Now the degree of drop ofthe battery capacity that is the capacity deterioration of the battery when a cycle test to repeat the charge and discharge of the lithium ion battery 2 will be described with reference to FIG 7 FIG 7 is a graph depicting the degree of the drop of battery capacity when a cycle test to repeat charge and discharge is performed for a year where the abscissa indicates the depth of discharge DOD and the ordinate indicates the deterioration degree 96 Here the temperature of the lithium ion battery 2 is held to about 50 C using the temperature adjustment device 5 and this temperature is regarded as a test temperature FIG 7 shows the degree of drop of the battery capacity in the cycle test when the depth of discharge DOD is constant For the depth of discharge values
31. o FIG 3 While DC power P2 is being input from the charge control circuit 3 to the lithium ion battery 2 inserted in the battery testing device 100 for charging input control step when the lithium ion battery 2 reaches a fully charged state the charge control circuit 3 stops charging the lithium ion battery 2 using the AC adapter 1 while the charge 20 25 30 35 40 45 50 55 60 65 6 control circuit 3 sends a discharge start signal Sdis to the radio circuit 4 and the radio circuit 4 which received this signal starts discharging the DC power P3 ofthe lithium ion battery 2 output control step Then the voltage Vb ofthe lithium ion battery 2 reaches a predetermined voltage above mentioned recharge start volt age Vstart state the charge control circuit 3 sends a charge stop signal Sdissstop to the radio circuit 4 and the radio circuit 4 which received this signal stops the discharge of the lithium ion battery 2 while the charge control circuit 3 starts charging the lithium ion battery 2 using the AC adapter 1 Here a predetermined voltage recharge start voltage Vstart state is a state where the need to start charging the lithium ion battery 2 is generated Inthis way one discharge ofthe lithium ion battery 2 by the radio circuit 4 and one charge of the lithium ion battery 2 using the AC adapter 1 by the charge control circuit 3 are regarded as one cycle and this cycle is repeated Now the change of each
32. ondary battery in the portable telephone being connected for charging can be correctly evaluated Itis preferable that the output control means discharges the secondary battery until reaching a state of 9596 of battery capacity in fully charged state when the secondary battery reaches the fully charged state Since charge and discharge arerepeated in the fully charged state and highly charged state of 9596 of battery capacity in the fully charged state capacity deterioration of the secondary battery progresses more quickly Hence performance of the secondary battery can be accurately evaluated in a shorter time It is preferable that the battery testing device further has temperature adjustment means for adjusting the temperature of the secondary battery wherein the input control means controls the input power which is input to the secondary battery at a temperature adjusted by the temperature adjust ment means using the charging means and the output control means discharges the secondary battery by controlling the output power which is output from the secondary battery at a US 8 228 039 B2 3 temperature adjusted by the temperature adjustment means Thereby input power control and output power control are performed for the secondary battery at a temperature adjusted by the temperature adjustment means Hence the influence of temperature on performance of the secondary battery can be more accurately evaluated It is preferable that t
33. s performed where the abscissa indi cate the test time and the ordinate indicates the setting tem perature by the temperature adjustment device 5 In this case when the battery capacity of the lithium ion battery 2 dete riorates to a predetermined ratio e g 7596 of the battery capacity of the lithium ion battery 2 that is not in use 100 the temperature adjustment device 5 increases the tempera ture of the lithium ion battery 2 from about 50 C which is a normal test temperature to about 150 C and then holds temperature at about 150 C for three hours Here the case when the temperature of the lithium ion battery 2 spontane ously changes will be described later Now the change of battery capacity of the lithium ion battery 2 due to the change of test time when the cycle test to repeat charge and discharge ofthe lithium battery 2 will be described with reference to FIG 11 FIG 11 isa graph depict ing a change of battery capacity of the lithium ion battery 2 due to the change of test time when the cycle test to repeat charge and discharge is performed where the abscissa indi cates the test time and the ordinate indicates the setting temperature by the temperature adjustment device 5 Here 5 DOD is the test condition and the test is performed with holding the temperature at about 50 C After the battery capacity of the lithium ion battery 2 reaches 75 50 or 2596 ofthe battery capacity ofthe lithium ion battery wh
34. s to the radio circuit 4 that is turns ON dis and the radio circuit 4 which received this signal starts discharge of the power P3 ofthe lithium ion battery 2 In this discharge period timings Tc to Td the battery Vb of the lithium ion battery 2 decreases from about 4 2 V and when the voltage Vb becomes about 4 0 V which is the recharge start voltage Vstart timing Td the recharge control circuit 3 sends the discharge stop signal Sdisstop to the radio circuit 4 that is turns OFF Sdis and the radio circuit 4 which received this signal stops the discharge ofthe lithium ion battery 2 whilethe charge control circuit 3 starts the charge ofthe lithium ion battery 2 using the AC adapter 1 Inthis way one discharge ofthe lithium ion battery 2 by the radio circuit 4 and one charge of the lithium ion battery 2 by the charge control circuit 3 using the AC adapter 1 are regarded as one cycle and this cycle is repeated Now a concrete circuit configuration to implement the configuration ofthe battery testing device 100 shown in FIG 3 will be described with reference to FIG 5 FIG 5 is a circuit diagram for depicting the concrete circuit configuration to implement the configuration ofthe battery testing device 100 Inorder to implement the configuration of the battery testing device 100 the switches 21 and 24 FET 22 Field Effect Transistor and the current detection resistor 23 are disposed Now the change of each index such as the curre
35. ut control step while the discharge of the secondary battery is stopped in the output control step Whereby the discharge of the secondary battery starts when the secondary battery reaches the fully charged state and the charge of the secondary battery starts when the secondary battery reaches the predetermined charged state and this cycle is repeated Therefore load is applied to a portable telephone by performing the charge and discharge of the secondary battery conforming to the actual way of use of the portable telephone such as using the por table telephone while being connected to such charging means as an AC adapter for charging thereby the perfor mance of the secondary battery in the portable telephone being connected for charging can be correctly evaluated According to the present invention a battery testing device and battery testing method which allows accurately evaluat ing the performance of a secondary battery in a portable telephone being connected for charging by applying aload of performing the charge and recharge of the secondary battery conforming to the actual way of use of a portable telephone can be provided BRIEF DESCRIPTION OF THE DRAWINGS FIG 1is a diagram depicting a state when an AC adapter is connected to a portable telephone FIG 2 is a graph showing an example of the change of battery voltage when charge and recharge are repeated in a lithium ion battery being connected for charging FIG 3 is a dia
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