iPad充電器給iPhone充電：安全

iPhone充電(dian)器(qi)給(gei)iPad充電(dian)：難說

iPhone充(chong)電(dian)(dian)器給iPhone充(chong)電(dian)(dian)（完全放電(dian)(dian)）

iPad充(chong)電(dian)器給iPhone4s充(chong)電(dian)（完全放電(dian)）

在蘋果官網的(de)技術支持區里有(you)這樣一段說明：iPad USB電(dian)源適(shi)配器(qi)是(shi)一個10W的(de)充(chong)電(dian)器(qi)。雖然此iPad 10W USB電(dian)源適(shi)配器(qi)設計(ji)為供(gong)iPad使用(yong)，但是(shi)您(nin)仍(reng)可(ke)通過(guo)其對所有(you)iPhone和iPod機(ji)型充(chong)電(dian)。

但(dan)對(dui) “果粉”來說，有(you)條微博(bo)讓人很(hen)糾結：請(qing)不要用iPad的充(chong)電(dian)(dian)器為iPhone充(chong)電(dian)(dian)，雖然它們看起來長得一樣，兩者的充(chong)電(dian)(dian)電(dian)(dian)壓也(ye)都是5V，但(dan)是iPhone充(chong)電(dian)(dian)的額定電(dian)(dian)流是1A，而iPad卻(que)是2.1A……混用充(chong)電(dian)(dian)器的后果是既傷(shang)(shang)iPhone又傷(shang)(shang)iPad充(chong)電(dian)(dian)器”。

iPad和(he)iPhone充電(dian)器到底能不能混用(yong)？口說無憑，實驗(yan)為證，《好奇(qi)實驗(yan)室(shi)》為你實測(ce)。

實(shi)驗對象：兩(liang)臺iPad、一臺iPad2、一臺iPhone4、一臺iPhone4s

中國計(ji)量(liang)學院(yuan)機(ji)電工(gong)程學院(yuan)的蔡慧老師說，iPad充(chong)電器的功率10W，是指電源(yuan)的最大輸出功率，但實際輸出功率要取決(jue)于所接的負載(zai)；iPad和iPhone的充(chong)電器的額定電壓都(dou)是5V，只要實際電流不超過額定電流（即iPhone1A，iPad2.1A），也不會對充(chong)電設備造成傷害。

iPad和(he)(he)iPhone的充電(dian)器(qi)(qi)連(lian)接線(xian)(xian)(xian)都是一樣的，我們把它剪斷，里面有(you)紅(hong)黑(hei)白綠(lv)(lv)(lv)四(si)條線(xian)(xian)(xian)，經(jing)檢(jian)測，紅(hong)線(xian)(xian)(xian)是電(dian)源線(xian)(xian)(xian)，黑(hei)線(xian)(xian)(xian)是地線(xian)(xian)(xian)，當(dang)連(lian)接線(xian)(xian)(xian)和(he)(he)iPad充電(dian)器(qi)(qi)相連(lian)時，在白線(xian)(xian)(xian)和(he)(he)綠(lv)(lv)(lv)線(xian)(xian)(xian)上分別檢(jian)測到了(le)2V和(he)(he)2.7V電(dian)壓，而當(dang)連(lian)接線(xian)(xian)(xian)和(he)(he)iPhone充電(dian)器(qi)(qi)連(lian)接時，白、綠(lv)(lv)(lv)兩(liang)條線(xian)(xian)(xian)上沒有(you)測到電(dian)壓。

“白、綠兩(liang)條線是(shi)信號線，當iPad或iPhone接上充(chong)電器時，通過這兩(liang)條線可以區分當前使用的(de)是(shi)哪種充(chong)電器，能對負(fu)載做出相應的(de)調(diao)整。”蔡慧(hui)老師說。

我(wo)們(men)先用萬能表對(dui)各種充電方式進(jin)行檢測。

iPad充(chong)電器（單位：A） iPhone充(chong)電器（單位：A）

50%電量的iPadA 1.5 0.48

60%電量的iPadB 1.5 1.26

70%電量的iPad2 1.4 0.48

39%電量的(de)iPhone4 0.98 0.45

40%電量的iPhone4s 0.88 0.9

從檢測結果看，iPad充(chong)電器(qi)給iPhone充(chong)電時，實際電流都低于1A，而用iPhone充(chong)電器(qi)給iPad充(chong)電時，iPadA和iPad2顯示(shi)“沒有充(chong)電”，顯示(shi)“正在充(chong)電”字樣的(de)iPadB的(de)實際電流偏(pian)大，超(chao)過了(le)1A。

“iPadB里的(de)一(yi)些系統(tong)軟件(jian)可(ke)能被(bei)更改了，導(dao)致這樣(yang)的(de)問題出現，用iPhone充(chong)(chong)(chong)電(dian)器(qi)充(chong)(chong)(chong)電(dian)時，iPad是不會(hui)有損(sun)傷的(de)，因為電(dian)流(liu)小(xiao)于額定(ding)電(dian)流(liu)，但對充(chong)(chong)(chong)電(dian)器(qi)會(hui)有損(sun)傷，時間一(yi)長，充(chong)(chong)(chong)電(dian)器(qi)就會(hui)壞(huai)掉。”

我們注意到(dao)，不同電(dian)量(liang)的(de)(de)設備，充電(dian)的(de)(de)實(shi)際電(dian)流大(da)小(xiao)(xiao)也是(shi)不一樣的(de)(de)，蔡老(lao)師(shi)解(jie)釋說(shuo)，這是(shi)因為智能(neng)電(dian)池(chi)在(zai)充電(dian)過程中，為了保持(chi)電(dian)池(chi)不受傷害，所以電(dian)流的(de)(de)大(da)小(xiao)(xiao)是(shi)會發生改變的(de)(de)。

為更詳(xiang)細地(di)了解(jie)整(zheng)個充電(dian)過程(cheng)，我們(men)(men)決定把iPad和iPhone完全(quan)放電(dian)到(dao)0%后，再進行(xing)充電(dian)，并用萬(wan)能表連接電(dian)腦(nao)來記錄整(zheng)個充電(dian)過程(cheng)――由(you)于時(shi)間(jian)關系(xi)，我們(men)(men)選擇了iPad2和iPhoe4s來進行(xing)實(shi)驗。

時間 實(shi)際電(dian)流（單位：A）

iPhone4s充電器充iPhone4s 約4小(xiao)時(shi) 0.8以(yi)下(xia)

iPhone4s充電器(qi)充iPad2 約14小時 0.5以下(xia)

iPad2充電(dian)器充iPhone4s 約3小時(shi) 0.83以下

iPad2充電器充iPad2 約(yue)9小時(shi) 1以下

從檢測結果看，iPad充電(dian)(dian)(dian)(dian)器給iPhone4s充電(dian)(dian)(dian)(dian)時(shi)，電(dian)(dian)(dian)(dian)流(liu)一(yi)(yi)直都在額(e)定電(dian)(dian)(dian)(dian)流(liu)以下，比用(yong)iPhone充電(dian)(dian)(dian)(dian)器充電(dian)(dian)(dian)(dian)的電(dian)(dian)(dian)(dian)流(liu)稍大，速度(du)也(ye)稍快一(yi)(yi)些；用(yong)iPhone充電(dian)(dian)(dian)(dian)器給iPad充電(dian)(dian)(dian)(dian)時(shi)，雖然iPad上(shang)沒有(you)顯示充電(dian)(dian)(dian)(dian)，但實際上(shang)一(yi)(yi)直在充電(dian)(dian)(dian)(dian)，只是(shi)需要的時(shi)間相當(dang)長。

但不管哪種方式充(chong)電，整個(ge)充(chong)電過程中的電流都是先低后高，然后慢(man)(man)慢(man)(man)下降，當電量到90%左右時(shi)，電流會越(yue)來越(yue)小。

“如(ru)果開(kai)始充(chong)電(dian)(dian)(dian)時(shi)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)量很低，那么必須用(yong)小電(dian)(dian)(dian)流(liu)開(kai)始充(chong)電(dian)(dian)(dian)，小電(dian)(dian)(dian)流(liu)充(chong)電(dian)(dian)(dian)是為了保護電(dian)(dian)(dian)池(chi)，避免大電(dian)(dian)(dian)流(liu)沖擊給電(dian)(dian)(dian)池(chi)內部(bu)結構帶來損害；而當電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)(ya)達到或接近充(chong)滿電(dian)(dian)(dian)壓(ya)(ya)時(shi)，則要開(kai)始轉入恒(heng)壓(ya)(ya)充(chong)電(dian)(dian)(dian)，如(ru)果不(bu)轉入小電(dian)(dian)(dian)流(liu)充(chong)電(dian)(dian)(dian)，就可能導(dao)致電(dian)(dian)(dian)壓(ya)(ya)過(guo)高，有過(guo)充(chong)的危險，也是對電(dian)(dian)(dian)池(chi)有害的。”蔡(cai)老(lao)師說。

但(dan)即(ji)使(shi)是用iPad充(chong)電器(qi)給iPad充(chong)電，實際電流也沒(mei)有大于1A，這是為什么呢？

蔡(cai)老師說，iPad和iPhone會根據電(dian)池(chi)的余量來選擇充電(dian)方案，當(dang)電(dian)池(chi)完(wan)(wan)全耗光(guang)時，就相當(dang)于一(yi)(yi)個餓(e)了很(hen)長(chang)時間的人(ren)，不能一(yi)(yi)下子進食太(tai)多，而應該一(yi)(yi)點一(yi)(yi)點慢(man)慢(man)吃，所以完(wan)(wan)全放電(dian)后充電(dian)，比有余電(dian)時充電(dian)的電(dian)量更小一(yi)(yi)些，時間也更長(chang)一(yi)(yi)些。