tws BLP661 User manual

广州明美新能源有限公司
TWSTECHNOLOGY(GUANGZHOU)LIMITED
--- TWS Confidential ---
THIS DOCUMENT AND THE SPECIFICATION CONTAINED HEREIN ARE PROPRIETARYAND NOT TO BE USED,
COPIED, REPRODUCED, OR OTHERWISE DEALT WITH NOR ITS CONTENTS COMMUNICATED TO OTHERS EXCEPT
IN ACCORDANCE WITH WRITTEN INSTRUCTIONS RECEIVED FROM TWS.
Form No.: TWS-IMS-2001-01—03c REV：A
Battery Specification
电池规格书
In compliance with OPPO standard
供货满足 OPPO 企业标准
Customer Name/客户名称: OPPO
Product Name/产品名称: Lithium-ion Polymer battery/聚合物锂离子电池
Product Model/产品型号: BLP661
TWS P/N /明美 P/N:
Customer P/N /客户 P/N:
Cell Model/电芯型号: ATL GC-SDC-386581-020L
Document No./文件编号: RD-PSP-BLP661-01
Revision Level/文件版本: 01
CustomerApproval
客户承认栏
广州明美新能源有限公司
TWSTECHNOLOGY(GUANGZHOU)LIMITED
Prepared by/拟制 Reviewed by/审核 Approved by/审批
Robbin Hu/
Junco Huang
2017-12-14

Document name/
文件名称
Battery Specification/
电池规格书
Product Model/
产品型号 BLP661
Document NO/
文件编号 RD-PSP-BLP661-01 Revision/版本 01
Date/日期 2018-01-03 Page/页码 1/ 18
--- TWS Confidential ---Form No.: TWS-IMS-2001-01--04c REV：C
History of Change
修订履历表
NO/
序号 Rev/ 版本 ECN NO./ ECN 编号 Content of Change/修订内容 Date/日期 Prepared by/
修订者
1 00 \ First draft/初版 2017-12-14
Robbin Hu/
Junco Huang
2 01 \ Update pack drawing/更新成品
图，原理图和 layout 2018-01-03 Robbin Hu/
Junco Huang

Document name/
文件名称
Battery Specification/
电池规格书
Product Model/
产品型号 BLP661
Document NO/
文件编号 RD-PSP-BLP661-01 Revision/版本 01
Date/日期 2018-01-03 Page/页码 2/ 18
--- TWS Confidential ---Form No.: TWS-IMS-2001-01--04c REV：C
Table of Contents/目录
1Scope/适用范围.......................................................................................................................................... 3
2Test reference standard/测试参考标准.......................................................................................................3
3Product name and model/产品名称和型号................................................................................................3
4Key parameters/主要参数 ..........................................................................................................................3
5Test methods and definitions/测试方法和定义..........................................................................................5
6Performance/基本性能 ...............................................................................................................................5
7Environmental Adaptability/环境适应性 ...................................................................................................7
8Safety and protection performance/安全保护性能 ....................................................................................8
9Storage performance /贮存性能 .................................................................................................................9
10Battery key component list and Spec/电池主要零件清单和规格. ..........................................................10
11PCM parameters/保护板主要零件清单...................................................................................................10
12Environmental requirements/环保要求.................................................................................................... 11
13Cosmetic requirements/外观要求............................................................................................................. 11
14Battery outlines and dimensions/外形结构及尺寸规格 ..........................................................................12
15Transportation and storage/运输、贮存...................................................................................................12
16Safeguard and instruction/安全规程和使用说明.....................................................................................12
17Quality Assessment Procedures/质量评定程序 .......................................................................................15
18Miscellaneous/其他事项 ..........................................................................................................................16
19Drawing/附图 ...........................................................................................................................................16

Document name/
文件名称
Battery Specification/
电池规格书
Product Model/
产品型号 BLP661
Document NO/
文件编号 RD-PSP-BLP661-01 Revision/版本 01
Date/日期 2018-01-03 Page/页码 3/ 18
--- TWS Confidential ---Form No.: TWS-IMS-2001-01--04c REV：C
1Scope/适用范围
This specification applies to the BLP661 battery designed and manufactured for OPPO by TWS TECHNOLOGY
(GUANGZHOU) LIMITED./本规格书适用于广州明美新能源有限公司为广东欧珀移动通信有限公司设计
和生产的 BLP661 电池产品。
2Test reference standard/测试参考标准
The battery is tested in reference to the standard of GB 31241-2014 “General specification of lithium-ion cells and
batteries for mobile phone”. /本产品测试参考标准: GB31241-2014《便携式电子产品用锂离子电池和电池组安
全要求》。
3Product name and model/产品名称及型号
Product Name/产品名称: Lithium-ion Polymer Battery/聚合物锂离子电池
Product Model/产品型号: BLP661
Configuration/结构: 1S1P
4Key parameters/主要参数
4.1 Cell characteristics /电芯特性
Cell maker/
电芯制造商
Cell model/
电芯型号
Rated voltage (V)/
额定电压(V)
Min.Capacity(mAh)/
额定容量(mAh)
ATL GC-SDC-386581-020L 3.85V 3355 mAh
4.2 Battery characteristics/电池特性
No/序号 Item/项目 Battery Specification/电池规格 Notes/备注
4.2.1 Typical capacity/典型容量 3400mAh
4.2.2 Rated capacity/额定容量 3300mAh
4.2.3 Nominal voltage/标称电压 3.85V
Measure with
multimeter HP34401/
HP34401 万用表测量
4.2.4 Charge method/充电方式 CC / CV
4.2.5 Rated charge voltage Ucr/
充电限制电压 4.4V
4.2.6 Charge upper limit voltage Uup/
充电上限电压 4.4V
4.2.7 Discharge cut-off voltage Udo/
放电截止电压 2.5V
4.2.8 Recommended charge current Icr/
推荐充电电流 0.2C
4.2.9
Cell Max. continuouscharge
current Icm1/
最大充电电流
2000mA
4.2.10 Upper limit charge temperature
Tcm/上限充电温度
0℃~10℃0.2 CminMax to 4.4V
10℃~20℃0.5CminMax to 4.4V
20℃~45℃2000mACminMax to

Document name/
文件名称
Battery Specification/
电池规格书
Product Model/
产品型号 BLP661
Document NO/
文件编号 RD-PSP-BLP661-01 Revision/版本 01
Date/日期 2018-01-03 Page/页码 4/ 18
--- TWS Confidential ---Form No.: TWS-IMS-2001-01--04c REV：C
4.4V
45°C ~ 55°C 0.3Cmin Max to 4.1V
4.2.11
Lower limit charge temperature
Tlm/
下限充电温度
0°C
4.2.12 Upper limit discharge temperature
Tdm/上限放电温度 60℃
4.2.13 Lower limit discahrge
temperature Tlm/下限放电温度 -20℃
4.2.14 Cycle life/循环寿命 >500cycles
4.2.15 Internal impedance/出厂内阻 ≦80mΩ
Measure with:
HIOKI3560/
HIOKI3560 测量
4.2.16
Length/长度尺寸 82(max)mm
Measure with Caliper/
卡尺测量
Width/宽度尺寸 64.8(max)mm
Thickness/厚度尺寸 3.9(max)mm
4.2.17 Weight/重量 About 47g/约47g
Measure with
Electronic scale/
电子秤称量
4.3 PCM specification（at 25℃）/保护板规格(在25℃)
NO./序号 Item/项目 Min/最小值 Typ/典型值 Max/最大值
4.3.1 Overcharge protection voltage (V)/
过充保护电压(V) 4.455 4.475 4.495
4.3.2 Overcharge protection delay time(s)/
过充保护延迟时间(s) 0.7 1 1.3
4.3.3 Overdischarge protection voltage(V)/
过放保护电压(V) 2.55 2.6 2.65
4.3.4 Overcurrent protection delay time (ms)/
过放保护延迟时间(ms) 14 20 26
4.3.5 Short-circuit protection time(µs)/
短路保护时间(µs) 175 250 425
4.3.6 PCM current consumption (µA)/
保护板消耗电流(µA)
Operating mode/工作模式
120uA,typ.
4.3.7 Overdischarge current protection (A)/
过放电流保护(A) 6.87 8 9.11
4.3.8 Discharging overcurrent detection delay time（ms）
过放电流保护延迟时间（ms）8 12 16
4.3.9 Overcharge current protection (A)/
过充电流保护(A) 5.15 6 6.83
4.3.10 Charging overcurrent detection delay time（ms）
过充电流保护延时时间（ms）11 16 21

Document name/
文件名称
Battery Specification/
电池规格书
Product Model/
产品型号 BLP661
Document NO/
文件编号 RD-PSP-BLP661-01 Revision/版本 01
Date/日期 2018-01-03 Page/页码 5/ 18
--- TWS Confidential ---Form No.: TWS-IMS-2001-01--04c REV：C
5Test methods and definitions/测试方法和定义
5.1 Test conditions/测试条件
5.1.1 Unless otherwise specified, tests in this specification should be conducted at the following atmospheric
conditions:/除非另有规定，本规格书中各项试验应在以下大气条件下进行：
5.1.2Temperature/温度: 20℃±5℃;
5.1.3Relative humidity/相对湿度: no greater than 75% /不大于 75%;
5.1.4Atmospheric pressure/大气压力：86 kPa-106 kPa.
5.2 Test instruments requirements/测试仪器要求
5.2.1 The precision of voltage measuring instrument should not be lower than ±0.5%. /
电压测量仪器的精度不应低于 0.5%。
5.2.2 The precision of current measuring instrument should not be lower than±0.5％. /
电流测量仪器的精度不应低于 0.5%。
5.2.3 The precision of time measuring instrument should not be lower than ±0.1％. /
时间测量仪器的精度不应低于 0.1%。
5.2.4 The precision of temperature measuring instrument should not be lower than ±0.5℃. /
温度测量仪器的精度不应低于 0.5℃。
5.2.5 The current of the constant current power supply can be adjusted; the relative variation of its current
should be in the range of ±1% at constant charge or discharge. /
恒流电源的电流可以调整，电流的相对变化应 1%范围内。
5.2.6 The voltage of the constant current power supply can be adjusted; the relative variation of its voltage
should be in the range of ±1% at constant charge. /
恒流电源的电压可以调整，电压的相对变化应在 1%范围内。
6Performance/基本性能
C5is the battery capacity indicated by the manufacturer. It is the capacity that a battery should have when it is
discharged to the cut-off voltage by 5-hour ratio at the ambient temperature of 23℃±5℃.
ItA is referential test current and ItA is equal to C5Ah/1h.
C5 : 生产厂标明的电池容量，指电池在环境温度为 23℃±5℃条件下，以 5h 率放电至 3.0V 时所应提供的电
量，用 C5表示。
ItA：参考试验电流用 ItA 表示，ItA=C5Ah/1h
No. Test item Test method Criteria
6.1 Charge
method/充电方
式
a standard
charge/
a 标准充电
b fast charge
b 快充
The battery may
be charged by
Standard charge : At ambient temperature of （23±5）℃,
charge the battery at 0.2ItA until the battery terminal
voltage reaches charge limit voltage, then charge at constant
voltage until charge current no greater than 0.01ItA, the
maximum charge time should not be greater than 8 h. Stop
the charging./
在环境温度为（23±5）℃条件下，以 0.2ItA 充电，当电池
端电压达到充电限制电压时，改为恒压充电，直到充电电
流不大于 0.02ItA，最长充电时间不大于 8h，停止充电。
fast charge: At ambient temperature of （23±5）℃ , charge
the battery at 1 ItA until the battery terminal voltage reaches

Document name/
文件名称
Battery Specification/
电池规格书
Product Model/
产品型号 BLP661
Document NO/
文件编号 RD-PSP-BLP661-01 Revision/版本 01
Date/日期 2018-01-03 Page/页码 6/ 18
--- TWS Confidential ---Form No.: TWS-IMS-2001-01--04c REV：C
method a or b.
电池可以使用 a
或b方式充电
charge limit voltage, then charge at constant voltage until
charge current no greater than 0.01ItA, the maximum
charge time should not be greater than 8 h. Stop the
charging.
在环境温度为（23±5）℃条件下，以 1ItA 充电，当电池端
电压达到充电限制电压时，改为恒压充电，直到充电电流
不大于 0.02ItA，最长充电时间不大于 8h，停止充电。
6.2 Standard
discharge/
标准放电
a. Charge as per section 6.1 then store the battery for
0.5-1hour, discharge the battery at constant current of
0.2ItA to cut-off voltage at ambient temperature of
（23±5）℃. The test may be cycled for 5 times. Stop
the test when the battery capacity meets the criteria in
any one of the cycles.
a. 电池按 6.1 规定充电结束后搁置 0.5h～1h，在环境温度
为（23±5）℃的条件下以 0.2ItA 电流恒流放电至 3.0V。
上述实验可重复循环 5次，当有一次循环的电池容量符
合规定时试验即可停止。
The discharge time
shall not be less than
5 hours. /放电时间不
能少于 5小时。
Fast discharge/
快速放电
b. Charge as per section 6.1 then store the battery for
0.5-1hour, discharge the battery at constant current of
1ItA to cut-off voltage at ambient temperature of
（23±5）℃.
b. 电池按 6.1 规定充电结束后搁置 0.5h～1h，在环境温度
为（23±5）℃的条件下以 1ItA 电流恒流放电至 3.0V。
The discharge time
shall not be less
than 51 minutes. /放
电时间不能少于 51
分钟。
6.3 High
temperature
performance/
高温性能
Charge the battery per section 6.1, then place at 55℃±2℃
high temperature chamber and keep at that temperature for 2
hours and discharge at 0.2ItA to the cut-off voltage. The
discharging time should meet the criteria./ 电池按6.1 规定充
电结束后，放入 55℃±2℃的高温箱中恒温 2h，然后以 0.2
ItA 电流放电至截止电压，放电时间应符合判定标准
After the test, take out the battery and place at ambient
temperature of 23℃±5℃for 2 hours. Visually inspect the
battery and the battery should meet the criteria./ 该试验结束
后，将电池取出在环境温度 20℃±5℃的条件下搁置 2h，
然后目测电池外观，应符合判定标准。
1. The discharging
time should not be
less than 5 hours/
放电时间应不低
于5h
2. No cosmetic
deformation , no
rupture./ 电池外
观应无变形、无爆
裂。
Low
temperature
performance/
低温性能
Charge the battery per section 6.1, then place at -10℃±2℃
low temperature chamber and keep at that temperature for 4
hours and discharge at 0.2ItA to the cut-off voltage. The
discharging time should meet the criteria. /电池按 6.1 规定充
电结束后，放入-10℃±2℃的低温箱中恒温 4h，然后以
0.2ItA 电流放电至截止电压，放电时间应符合判定标准。
After the test, take out the battery and place at ambient
temperature of 23℃±5℃for 2 hours. Visually inspect the
battery and the battery should meet the criteria. /该试验结束
1. The discharging
time should not be
less than 3 hours./
放电时间不低于
3h。
2. No cosmetic
deformation, no
rupture./ 电池外
观应无变形、无爆
裂。

Document name/
文件名称
Battery Specification/
电池规格书
Product Model/
产品型号 BLP661
Document NO/
文件编号 RD-PSP-BLP661-01 Revision/版本 01
Date/日期 2018-01-03 Page/页码 7/ 18
--- TWS Confidential ---Form No.: TWS-IMS-2001-01--04c REV：C
后，将电池取出在环境温度 20℃±5℃的条件下搁置 2h，
然后目测电池外观，应符合判定标准。
6.4 Capacity
retention/
容量保持能力
Charge each sample battery per section 6.1, and then store the
battery for 28 days at ambient temperature of 20℃±5℃and
discharge at constant current of 0.2 ItA to cut-off voltage. /每
个电池按 6.1 规定充电结束后，在环境温度为 20℃±5℃条
件下，将电池开路搁置 28 天，在环境温度为 23℃±2℃条
件下在再以 0.2ItA 放电至截止电压。
The discharge time
should not be less
than 4.5h. /放电时
间不低于 4.5h。
6.5 Cycle life/
循环寿命
At the ambient temperature of （23±5）℃, check the capacity
every 50 cycles, the cycle life indicates at the rate of 50, the
test should be conducted as follows. Repeat the 1-50 cycles.
Charge and discharge, store for 0.5h~1h,until the discharge
time of any one of the 50th cycle is less than 3h, subject to one
cycle per the 50th cycling instruction, if the discharge time is
still lower than 3h, this should be deemed the end of life of the
battery.
在环境温度为（23±5）℃条件下，试验过程中，每 50 次循
环做一次容量检查，电池寿命以 50 的倍数表示，步骤按下
表进行。重复进行 1~50 次循环，充放电直接搁置 0.5h~1h，
直至任一个第 50 次循环放电时间低于 3h 时，按照第 50 次
循环的规定再进行一次循环，如果放电时间仍然低于 3h 时，
则认为寿命截止。
No. of
cycles/
循环次
数
Charge/充电 Discharge/放电
Charge
current/
充电电
流
Charge
limit
voltage/
充电限
制电压
Cut-off
current/
截止电
流
Discharge
current/
放电电流
Cut off
voltage/
截止电
压
1~49 1ItA 4.35V 0.1ItA 1ItA 2.75V
50 0.2ItA 4.35V 0.02ItA 0.2ItA 2.75V
Cycle life should not
be less than 500
cycles./循环次数不
低于 500 次。
7Environmental Adaptability/环境适应性
No./序
号Test item/ 测 试项目 Test method/测试方法 Criteria/判定标准
7.1 Constant
Humidity and
Temperature
Characteristics/
恒温恒湿性能
Place a fully charge battery to constant humidity chamber
with RH of 90%～95% and temperature of 40℃±2℃for 48
h. /将满电电池放入温度40℃±2℃、相对湿度90%～95%
恒湿箱中试验48h；
Take out the battery from the constant humidity chamber and
place them at ambient temperature of 23℃±2℃for 2 hours,
visually inspect the battery appearance. /从恒湿箱中取出电
池，在23℃±2℃的环境温度下搁置2h，目测电池组外观，
以0.2ItA放电至3.0V3.0V
1. discharge time≥3h/
放电时间大于3h。
2. There should be no
deformation, no
rust, no leakage, n
rupture, no fire and
no explosion./电池
应不破损、不生
锈、不起火、不爆
炸、不漏液。

Document name/
文件名称
Battery Specification/
电池规格书
Product Model/
产品型号 BLP661
Document NO/
文件编号 RD-PSP-BLP661-01 Revision/版本 01
Date/日期 2018-01-03 Page/页码 8/ 18
--- TWS Confidential ---Form No.: TWS-IMS-2001-01--04c REV：C
7.2 Vibration/震动 After charging the battery, and secure the battery on the top of
vibration table without distorting the battery. the vibration
should be a sinusoidal waveform with a logarithmic sweep
between 7 Hz and 200 Hz and back to 7 Hz traversed in
15minutes. This cycle should be repeated 12 times for a
total of 3 hours for each of three mutually perpendicular
mounting positions of the battery. One of the directions of
vibration must be perpendicular to the terminal face. / 电池
充满电后，将电池固定在振动台上，不可使电池变形。采
用正弦波进行振动，并以对数扫频方式在 15min 内从 7Hz
扫频到 200Hz 并返回到 7Hz。振动沿样品互相垂直的三个
方向（其中一个方向必须与样品正负极所在平面垂直）进
行，每个方向按上述对数扫频方式重复 12 次，振动 3h。
The logarithmic frequency sweep is as follows: from 7 Hz a
peak acceleration of 9.8m/s2 is maintained until 18 Hz is
reached. The amplitude is then maintained at 0.8 mm (1.6 mm
total excursion) and the frequency increased until a peak
acceleration of 78.4m/s2 occurs (approximately 50 Hz). A
peak acceleration of 78.4m/s2 is then maintained until the
frequency is increased to 200 Hz./ 对数扫频方式如下：
7Hz～18Hz保持9.8m/s2的峰值加速度。将振幅保持在
0.8mm（位移为1.6mm）直至峰值加速度达到78.4m/s2（频
率约为50Hz）。保持78.4m/s2的峰值加速度直到频率增长
到200Hz。
1. The open circuit
voltage should not
be lower than 90%
of the initial
voltage. There
should be no
leakage, no rupture,
no fire and no
explosion./ 电池开
路电压不小于规
格的90%。电池应
不起火、不爆炸、
不漏液。
2. Battery thickness
variation rate≤5%；
/电池厚度变化
≤5%。
3. After the test, the
battery should
present no obvious
cosmetic
difference./ 测试
后，电池表面无明
显变化。
7.3 Shock/冲击 Secure a battery on table top in each of the three mutually
perpendicular directions (X, Y and Z). Set the Peak
acceleration to 100 m/s2; Subject the battery to 40 to 80
times of shock per minute. Impulse duration is 16ms and
the total number of shocks is 1000±10 times. Take off the
battery from the test table, the appearance and the battery
voltage should meet the criteria. /将电池平均按 X、Y、Z相
互垂直轴向直接或通过夹具坚固在台面上，按下述要求调
好加速度、脉冲持续时间，进行碰撞试验：脉冲峰值加速
度100 m/s2；每分钟碰撞次数 40～80；脉冲持续时间 16ms；
碰撞次数 1000±10 次。碰撞结束后将电池自实验台取下，
电池外观及电池电压应符合判定标准。
1. No obvious
cosmetic damage,
no leakage, no
smoke or no
explosion./电池无
明显破损，不冒
烟、不爆炸、不漏
液。
2. Battery voltage
should not be lower
than 3.6V./电池电
压不低于3.6V。
7.4 Drop/跌落 Drop a battery from a height of 1 m to concrete floor. Each
battery face is subject to one fall, total six tests. /将电池从 1m
处自由落体跌落于混凝土板上，每个面各跌落 1 次，总共
6次。
No drop test request./
无跌落要求
8Safety and protection performance/安全保护性能

Document name/
文件名称
Battery Specification/
电池规格书
Product Model/
产品型号 BLP661
Document NO/
文件编号 RD-PSP-BLP661-01 Revision/版本 01
Date/日期 2018-01-03 Page/页码 9/ 18
--- TWS Confidential ---Form No.: TWS-IMS-2001-01--04c REV：C
Note: Adequate safeguard should be employed in conducting the following tests. / 注：以下安全性
能试验应在有保护措施的条件下进行。
No./序
号Test item/ 测 试项目 Test method/测试方法 Criteria/判定标准
8.1 Overcharge
Protection/
过充保护
Charge each sample battery per section 6.1 , and then charge
the battery at voltage 2 times of the rated voltage and at
constant current of 2C for 7 hours. After the test. The test
result should be in conformance with the criteria.
电池按 6.1 规定充电结束后，将电池以 2倍标称电压、2C
电流恒流恒压充电 7h，电池应符合判定标准。
The battery should
not explode, catch
fire, smoke or leak. /
电池应不爆炸、不起
火、不冒烟、不漏液。
8.2 Overdischarge
Protection/
过放保护
Discharge each sample battery at 0.2ItA to the cut-off
voltage, and then discharge the battery by connecting the
battery to a load of 30Ωfor 7 hours. The test should be
performed at ambient temperature of 23℃±5℃.The battery
should be in conformance with the criteria.
电池在环境温度为（23±5）℃条件下，以 0.2ItA 放电至 3.0V
后，外接 30Ω负载放电 7h，电池应符合判定标准。
The battery should
not explode, catch
fire, smoke or leak. /
电池应不爆炸、不起
火、不冒烟、不漏液。
8.3 Short-circuit
Protection/
短路保护
Charge each sample battery per section 6.1 , and then
short-circuit the battery for 1 hour by connecting the positive
and negative terminals with a resistor of 80mΩ±20 mΩ.
After the test, the battery should be in conformance with the
criteria. /电池按 6.1 规定充满电后，短路电池的正负极短路
1h，外部短路总电阻为 80mΩ±20 mΩ。测试后，电池应
符合判定标准。
The battery should
not explode, catch
fire, smoke or leak. /
电池应不爆炸、不起
火、不冒烟、不漏液。
9Storage performance /贮存性能
No./序
号Test item/ 测 试项目 Test method/测试方法 Criteria/判定标准
9.1 Storage
performance/ 贮
存性能
The batteries used for storage test should be less than 3 month
old from production date. Before storage, charge the battery to
40% to 50% capacity as per section 6.1. After that, store the
batteries at the ambient temperature of （23±5）℃ and
relative humidity of 45% to 85% for 12 months and charge
as per section 6.1 and discharge at 0.2ItA. The discharge
time should be in conformance with the criteria./ 储存测试需
要使用生产三个月以内的电池。储存之前需要按 6.1 规定
的方法给电池充入 40%～45%的容量，然后在环境温度 23℃
±5℃，相对湿度 45%～85%的环境中储存 12 个月。然后再
按 6.1 规定充电后，在 23℃±5℃的温度环境下以 0.2ItA
放电至截止电压。放电时间应符合判定标准
The discharge time
should not be less
than 4 hours./放电时
间不低于 4h。