Sunday, April 22, 2018

什麼是電池的CCA(Cold Cranking Amperes)? 如何量測CCA?

前陣子車子進廠保養,隔天保養回來後,上面夾了張小紙條。

電瓶檢測報告,測試結果良好,電壓12.6V,內阻6.21mΩ,壽命100%,CCA為439。

獻慶好奇的是,啥是CCA? 如何量測CCA?

電瓶檢測報告

以下將會一一討論
  1. 什麼是CCA?
  2. 如何量測CCA?
  3. CCA對照表 and 換算公式
  4. 市面上的CCA量測器
  5. 台灣湯淺電池公司對市面上CCA量測器的看法
  6. 歐洲湯淺電池公司對市面上CCA量測器的看法
  7. 結論


什麼是CCA?

根據ARTC車測中心的資料

CCA (Cold Cranking Amperes) 冷啟動電流安培數 (單位為安培 A)

用來定義電瓶在0°F(-17.8°C,通常會講-18°C)寒冷環境下啟動汽車引擎能力的指標,越高的CCA表示可提供引擎越大的冷啟動電力,尤其是車齡過高不易啟動的車輛,越高的CCA可以使引擎啟動更加順利。但一般購買電瓶時,我們無法從電瓶外觀、符號得知CCA,可以參考電瓶的電瓶安培數值(這裡指的是表示容量的安培小時數Ah),該數值與CCA成正比,或從電瓶製造廠提供的"電瓶規格"得知,這也是最準確的方式。若是完全無法得知,原先電瓶的CCA就只能推估,請參考表1。

汽車排氣量 (c.c.)CCA估計值 (A)
1200~1600350
1600~2000500
2000~3000650
3000以上750
表1 依排氣量推估電瓶CCA


順帶一提CA

CA (Cranking Amperes) 啟動電流 (單位為安培 A)

主要意義與CCA類似,與CCA差異的僅是測定時之溫度,CA則是在0°C環境下所得出的結果(CCA則是在0°F)。同一電瓶CCA的數值會比CA來得低,因為溫度愈低電池的表現會愈差。

(資料來源: ARTC車測中心: 知識庫 - 認識電瓶規格 )

如何量測CCA?

CCA cannot be “measured,” but it can be “estimated.” The process can take a week per battery. A full CCA test is tedious and is seldom done. To test CCA, apply different discharge currents to see which amperage keeps the battery above a set voltage while cold. Table 2 illustrates the test procedures according to SAE J537, IEC, and DIN. The methods are similar and only differ in the length of discharge and the cut-off voltages.

SAE J537 CCA testIEC CCA testDIN CCA test
Fully charge battery according
to SAE J537 and cool to -18°C (0°F) for 24 hours. While at subfreezing temperature, apply a discharge current equal to the specified CCA. (500 CCA battery discharges at 500A.) To pass, the voltage must stay above 7.2V (1.2V/cell) for 30 seconds.
Fully charge battery according
to SAE J537 and cool to -18°C (0°F) for 24 hours. While at subfreezing temperature, apply
a discharge current equal to the specified CCA. (500 CCA battery discharges at 500A.) To pass, the voltage must stay above 8.4V for 60 seconds.
Fully charge battery according
to SAE J537 and cool to -18°C (0°F) for 24 hours. While at subfreezing temperature, apply a discharge current equal to the specified CCA. (500 CCA battery discharges at 500A.) To pass, the voltage must stay above 9V for 30s and 6V for 150s.
Table 2 CCA test methods of SAE, IEC, and DIN. The methods differ in the length of discharge and the cut-off voltages.

看到英文的資訊,表示獻慶沒找到中文的。簡單翻譯一下

CCA無法"量測(measured)",但可"估計(estimated)"。同時,該實驗過程對每個電池而言,可能會長達一個星期。一個完整的CCA測試是很無聊而且也很少在做(除非是專業的大型電池廠)。在測試CCA時,使用幾個不同的電流,看看安培計有沒有在低溫下維持一定的電流,同時電壓也要維持在一定的準位之上(電池要維持住的最小電壓)。表2秀出了SAE J537、IEC、及DIN的測試流程。這些測試流程的差異僅在於放電時間長短及截止電壓大小。

表2重新做個小整理一下
電池充飽電後,將電池的溫度下降至-18°C (0°F),放置24小時。接著進行放電測試,實驗條件如下表所示。

SAE J537 CCA testIEC CCA test
DIN CCA test
放電時間 (sec)306030150
放電過程中
電壓要高於 (V)
7.2
(1.2V/cell)
8.4
(1.4V/cell)
9.0
(1.5V/cell)
6.0
(1.0V/cell)
表3 SAE J537、IEC、及DIN測試流程放電時間及電池要維持住的最小電壓。這裡的最小電壓是針對12V的電池而言。

(資料來源: BU-902a: How to Measure CCA。由於時間有限,中文的資料沒找到,倒是英文的資料,已經有人幫忙整理了。 ^_^)



由此可知,量測CCA不是一件容易的事情。而且不同的測試流程,所得到的CCA值也不一定相同。

進行CCA測試,首先要降溫。通常,是要將電池從車上拆下來,放進冰箱,冰到-18°C後,在放置24小時。當然,也可以整台車冰到-18°C...

接下來測放電能力,時間要超過規定的放電時間,而且電池的電壓還要保持在規定的電壓之上。

這種實驗可能要測好幾次,很少有機會做一次就會"猜到"CCA的值。可能在做第一次時,CCA猜的太小了,電壓還有空間可以下降。做第二次時,CCA猜過頭,電壓降到超過,不算。做第三次時,就猜得比較接近了...  第四次、第五次... 這算是苦功!

當然,也許已經有實驗室開發出,自動量測CCA儀器(很貴的那種,數百到幾千萬台幣...),有自動控制的幫忙,可以省下一堆功夫。

不過,連Yuasa都說自己做一輪實驗最少需要12個工作天...
(參考資料: Yuasa - Yuasa - All you need to know about batteries )

CCA對照表 and 換算公式

對同一顆電池來說,不同的測試流程,當然會得到不同的CCA數值。不同測試流程所得到的CCA是可以互相比較對照。

對照表

以下列出SAE、EN、IEC、DIN的CCA對照表

SAEENIECDIN
1001006560
1501409585
200180130110
250230160140
300280195170
350330225200
400360260225
450420290255
500480325280
550520355310
600540390335
650600420365
700640450395
900860580505
750680485420
950900615535
800760515450
1000940645560
850790550480
10501000680590
11001040710620
11501080745645
12001150775675
12501170810700
13001220840730
13501270870760
14001320905790
14501360935815
15001410975820
154014501000870
表4 SAE、EN、IEC、DIN的CCA對照表。

(資料來源: CCA: DIN, EN, SAE??? )



換算公式

SAE跟DIN間的換算公式
  1. SAE = (DIN ✕ 1.5) + 40
  2. DIN = (SAE - 40) ✕ 0.66



眼尖的讀者,可能會注意到換算公式跟對照表,是不太一致的。

例如:

DIN=60,算得SAE = (60 ✕ 1.5) + 40 = 130。但對照表上顯示SAE=100,差了30,感覺上誤差很大,30% (30/100)。

DIN=110,算得SAE = (110 ✕ 1.5) + 40 = 205。對照表上顯示SAE=200,只有差5,感覺上誤差就小多了,2.5% (5/200)。


所以說,不管公式或是對照表,都只是參考。趨勢是對的,準確性就沒辦法。無怪乎有那"CCA無法量測(measured),但可估計(estimated)"的感慨!

市面上的CCA量測器

我們知道CCA的量測困難又耗時,但為何車子送進保養廠保養,今天送,隔天保養好,上面連電池CCA的數據都給你了!

整個時間都還沒有24小時,電池連冰都沒冰過,這是怎麼回事? 

就算真的整台車拿去冰,也要超過24小時啊? 

正規的實驗流程,大概就要花上一周了,那麼這個CCA數據到底怎麼來的?



原來是市面上就有賣電池的CCA量測器,宣稱可以測量CCA,而且只要幾秒鐘就好。



當然有幾個問題,獻慶在此提出
  1. 該量測器宣稱可測得CCA。這是個奇怪的說法,在常溫下(25°C)去測得低溫下(-18°C)的CCA。怎麼會把常溫下量到的數據,說是低溫下的數據哩? 溫度根本不同啊!
  2. 還是有換算模型? 將常溫量到的數據轉換成低溫下的CCA? 
  3. 或者只是拿了量測CCA的工具,在常溫量測,然後誤解為該數值為CCA。其是量到的是CA或HCA (Hot Cranking Amperes)?
  4. 不過,大多的測試工具並未請使用者輸入現在溫度,可以猜測,可能是沒有溫差換算的模型。
  5. 只要幾秒鐘就量出來,那不就是不合SAE J537、IEC、及DIN的測試流程?




在此附上幾個市面上的CCA量測器連結供參考
  1. Midtronics - Battery and Electrical System Diagnostics
  2. MASHIN - 12V Battery Analyzer
  3. 2018年最新: 麻新VAT-600 12V 汽車電瓶測試器 電瓶 發電機 啟動馬達 蓄電池測試VAT600,可測100~2000CCA
  4. 汽車電池測試器-電瓶大師,精確檢測電池的電壓、冷啟動電流、內阻和壽命,可測100~1700CCA
  5. 汽車蓄電池檢測儀 DY2015 12V 電瓶檢測儀電池 電導內阻測試儀 蓄電池檢測儀 啟動電流、電壓 汽車 電動車
  6. <微控制器科技> DY2015 電瓶 蓄電池測試儀、內阻、壽命百分比、啟動電流、電壓
  7. 利器五金- 電瓶測試+ 汽車電瓶檢測器 電瓶檢測12V 電瓶檢測大師 保養廠 專業 好幫手 12/24V模式 電瓶檢測


台灣湯淺電池公司對市面上CCA量測器的看法

台灣湯淺的結論是: 市場上CCA測試器約5000元,時間3秒測出,目前在國際上,仍無技術可於幾秒內測出CCA值。

以下轉述內容


Q-10
何謂電池的CCA?
一.CCA:根據國家標準CNS規定,電池在零下-18℃冷凍20小時後,再使用超大電流
         放電設備放電30秒,才能換算CCA(冷凍曲軸啟動電流),設備費用約200萬元
         (如下表)
電池型號CNS放電電流日本規格JIS放電電流
46B24325A295A
55D23356A320A


二.重負荷壽命:CNS規定電池溫度在40~45℃環境中充電5小時→放電1小時,視為壽
                             命1回, 每25回用20A電流放電,電池容量少於50%,判定為壽命終止
電池型號CNS壽命標準規格JIS壽命標準總測試時間
46B24300回約75天
55D23315回315回約79天


三.由上可知壽命與CCA不相關
四.我國國家標準CNS以及日本規格JIS明文規定:
     電池型式僅有 1 種,絕無MF、CMF、SMF之分,這些都是市售簡易CCA/壽命測試
     器之製造商任意編撰,明顯違反國家標準。
五.市場上CCA測試器約5000元,時間3秒測出,目前在國際技術尚無法於幾秒內測出
      CCA值。

(資料來源: 台灣湯淺官網 - 常見問題。在汽車電池分項下的Q-10何謂電池的CCA? )

歐洲湯淺電池公司對市面上CCA量測器的看法

相較於台灣湯淺那"溫柔的言論",歐洲湯淺電池(GS Yuasa Battery Europe Ltd.)的評論就激烈多了
Digital conductance battery testers are not designed to check the cold cranking performance of a new battery.
(資料來源: Yuasa - Understanding the specifications )

翻譯過來就是說,
數位電導電池測試器不是設計來檢測新電池的CCA表現

"數位電導電池測試器"指的就是一般市面上的CCA量測器,只是這個名詞點出了該量測器的工作原理。

原理很簡單,就是內阻比較法,而且只針對幾種類型的鉛酸電池,才有內阻模型可比較,如果要測的那顆電池種類並不符合儀器中支援的內阻模型,那出來的數據就GG了。但銷售端幾乎都不說明量測原理,以及儀器適用範圍。可能認為大眾都是天才,都知道螢幕上顯示的CCA,並不是真正在低溫下做實驗得到的CCA...

PS: 歐洲湯淺針對數位電導電池測試器還講了不少東西,得等有空再整理了。當然,有興趣的觀眾可以自行參閱。

結論

CCA (Cold Cranking Amperes) 冷啟動電流 (單位為安培 A),是用來做為電池在-18°C(0°F)寒冷環境下啟動汽車引擎能力的指標,電池有越高的CCA表示可提供引擎越大的冷啟動電力,尤其是車齡過高不易啟動的車輛,越高的CCA可以使引擎啟動更加順利。

CCA有許多種量測的標準流程,例如: SAE、IEC、DIN等。不論是哪種標準流程,都要把溫度降到-18℃才開始量測。對同一個電池而言,各個標準流程所量得的CCA不盡相同,因而有CCA對照表及換算公式可做比較。

數位電導電池測試器不是設計來檢測新電池的CCA表現。市場上CCA測試器約1000~5000元,檢出時間約3~15秒,使用內阻比較法,但銷售端幾乎都不說明原理。可能認為大家都知道螢幕上顯示的CCA,並不是真正在低溫下做實驗得到的CCA。

儘管目前在國際上,仍無技術可於幾秒內測出CCA值。畢竟"幾秒內測出"這個條件已經違背標準流程中的"降溫至-18℃後,靜置24小時"這個基本要求。但人們總是會去想更快、更方便的方法,來得知電池的啟動能力,以及評估電池的好壞。


相關連結

ARTC車測中心: 知識庫 - 認識電瓶規格

Web: BU-902a: How to Measure CCA
提供test procedures according to SAE J537, IEC, and DIN。

Web: 【逢甲電池】汽車電池壽命剩幾趴 原廠檢測大公開 電瓶電壓 電容量 內阻 CCA
提到如何利用市面上的CCA量測器來欺騙消費者。透過輸入不當的CCA數值,得到不合理的結果,來蒙騙消費者。

PPT: [問題] 電瓶 CCA 測量請益

Forum: [其他] 市面上測試電瓶CCA的儀器準嗎?
提到台灣湯淺電池官方網站的說明 (市場上CCA測試器約5000元,時間3秒測出,目前在國際技術尚無法於幾秒內測出CCA值)

Web: 電瓶健康檢測器 開箱!
健康檢測器,連這種生活化的名字都出現了...

Patent: US6097193A Vehicle starting battery cold-cranking AMPS meter and method

Yuasa: https://www.centurybatteries.co.nz/getattachment/Technical-Support/Battery-Talk/CY103-2093-Battery-Talk-Newsletter-5_lr.pdf?lang=en-NZ
Wikipedia: https://en.wikipedia.org/wiki/Automotive_battery
HCA (Hot Cranking Amperes)
HCA is a measurement of the current a fully charged battery can deliver for 30 seconds and maintain a voltage of 7.2 volts (12-volt battery) at a temperature of 27°C (80°F~26.7°C). HCA is a rating specifically geared towards starting applications in warm conditions as the warmer the temperature the more available power from the battery. The HCA rating is not an official definition accepted by the industry.

提到做一輪實驗就需要最少12個工作天...
For example, the initial performance testing procedure according to the EN50342.1 A1 Nov 2011 requires a minimum of 12 working days of testing and significant resources in equipment to validate batteries. All Yuasa branded batteries sold into the market and regularly audit tested to ensure conformance to the relevant standard. 

對"數位電導電池測試器"的看法,有戳到痛點。
(typo很多,獻慶已經改了大半,如果有需要,再來翻譯)
Digital Conductance Testers Explained

As reported by most battery manufacturers, some confusion has been created within the battery industry regarding the apparent performance of batteries after tests conducted with digital conductance testers (e.g. Midtronics, Bosch BAT121 being the most common types currently on the market).

It is important that the purpose of these testers is clearly understood.

Digital conductance battery testers are not designed to check the cold cranking performance of a new battery.

They are purely designed for testing and evaluation of suspect or used batteries. Any CCA or state of health reading from the test CANNOT be a reliable guide as to the specification of the battery.

The BCI and European EN standard as a testing benchmark for the manufacturing process.

Yuasa Batteries (part of the GS Yuasa Corporation) is one of the largest manufacturers worldwide of Lead-acid automotive batteries and its batteries are designed to confirm to the internationally recognized standards.

For example, the initial performance testing procedure according to the EN50342.1 A1 Nov 2011 requires a minimum of 12 working days of testing and significant resources in equipment to validate batteries. All Yuasa branded batteries sold into the market and regularly audit tested to ensure conformance to the relevant standard.

The EN 50342 standard has created further confusion in the market by listed two conformance level standard for high rate cold cranking performance which are not clear to the end user without full access to the ETN part number listing.

EN1 Test @ -18°C 10s to 7.5V, 10 seconds rest than 60% of current to 6V where time should be greater than 73s.

EN2 Test @ -18°C 10s to 7.5V, 10 seconds rest than 60% of current to 6V where time should be greater than 133s.

The rating of the battery obviously varies subject to battery design, but for example, a battery rated at 1000A according to EN1 could only be rated at 920A according to EN2. The information of which standard the battery is rated is currently held within the ETN number e.g. 550 034 050<

550=> 12 Volt 50Ah battery

034=> Is a specific number to that battery which gives details of lid type, life, vibration resistance and also whether the battery conforms to EN1 or EN2 high rate

050=> High rate current in this case 500A

There are currently nearly 2000 individual battery numbers listed on the ETN database by different battery manufacturers and users. This currently makes it unclear to the customer to what rating the battery is capable of meeting EN1 or EN2 without access to the listing.

In order to minimize confusion, Yuasa currently uses the longer established American BCI SAE rating for cold cranking amps which is the current to deliver 30 seconds to 7.2V at a temperature of -18°C. This is seen as a fairer comparison to give a balanced view of the batteries durability and starting performance.

The evolution of the Conductance tester into the market

In the last ten years, comparatively inexpensive conductance meters have entered the market which are able to determine the specific internal resistance of an automotive battery using the principles of the AC Wheatstone bridge (which you may remember from school days). The clear advantage of these devices is that they are portable, easily operated, no sparking risks from carrying out traditional high rate load “drop” test and deliver results in just a few seconds.

Disadvantages

The disadvantage of the conductance tester is that they all use a standard algorithm (program) to estimate the CCA reading from the measured internal resistance reading. The values given by these meters are not comparable with those determined using the laboratory test equipment where batteries are physically discharged under real high discharge load, at a temperature of -18°C. Due to differences in battery designs, it is not possible to give a perfect relationship between internal resistance and actual performance in the laboratory.

Laboratory testing shows that the algorithm used in conductance testers penalizes batteries where the battery design has been optimized (with heavier high density, fine porosity plates) for durability/cyclic endurance than those designs optimized for high rate performance.

For the evaluation of new factory fresh batteries, different readings can be seen depending on the manufacturers' plate design and acid density. Even significantly different readings can be obtained between different brands of tester. Expanded plates give a higher reading than a cast plate, as the cast plate has a full frame construction for improved conductivity. The grid size can be reduced and made thicker to access the active materials toward the bottom of the plate. This design difference, for example, has a difference in the conductance readings where the tester correlates to the CCA reading based on a standard formula. The testing of new batteries is more complex as testing under the EN50342 standard requires the battery to be conditioned after a number of cycles which alter the conductance of the paste and hence causes more variation in tester data produced.

For this reason, Yuasa and other major battery manufacturers recommend that the confirmation of the compliance of unused batteries to the EN or BCI can only be determined using laboratory testing, and that digital conductance tester is not suitable to evaluate the performance of new unused batteries.

Conductance Tester is designed to measure the internal resistance of the battery. The testers effectiveness on a deeply discharged battery is less effective as although a good starting current figure can be indicated and the vehicle will start, it does not indicate that the 20 hour capacity of the battery may be as low as 10-30%. due to repetitive operation in low states of charge. It is suggested that if this is suspected, the battery should be tested after the lights have been left on for 15 minutes without the engine running.


2 comments: