為節約能源，試用太陽能給鎳氫電池充電。 最關心的是這樣做的成本多少，效果如何。試下來還算比較滿意的。太陽能電池用了３個單元串聯使用，這太陽能電池單元購于東明，一共３０元。在陽光下空載輸出的最高電壓超過了７Ｖ。這樣用這個太陽能電池對鎳氫電池組充電，充電電池是四(si)節鎳(nie)氫電(dian)池(chi)串聯。串聯一個電(dian)流表(biao)監視充電(dian)電(dian)流（100uA表(biao)頭并(bing)聯電(dian)阻改為100mA電(dian)流表(biao)）。沒(mei)有(you)什么線路，直接把電(dian)池(chi)組和(he)太陽能電(dian)池(chi)組并(bing)聯就(jiu)可以(yi)了。

    充電電流隨(sui)陽光強度變化，在無直射(she)的情況下(xia)，充電(dian)電(dian)流約１０多(duo)mA；

    強烈日(ri)光直射下，充電(dian)電(dian)流可以達到和(he)超(chao)過100mA。

    這(zhe)樣就行了，大家可(ke)以(yi)估算，在晴(qing)到多云天(tian)(tian)氣，每天(tian)(tian)充(chong)(chong)入電(dian)(dian)(dian)(dian)量約400-800mAh，這(zhe)樣一(yi)組(zu)實際(ji)容量2000mAh的鎳氫(qing)電(dian)(dian)(dian)(dian)池(chi)(chi)，３到６天(tian)(tian)可(ke)以(yi)充(chong)(chong)滿。不(bu)用擔心(xin)(xin)充(chong)(chong)電(dian)(dian)(dian)(dian)問題，對電(dian)(dian)(dian)(dian)池(chi)(chi)講(jiang)這(zhe)是涓流(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)。太(tai)陽(yang)(yang)能(neng)電(dian)(dian)(dian)(dian)池(chi)(chi)組(zu)放在窗臺外(wai)面，能(neng)曬(shai)(shai)到太(tai)陽(yang)(yang)的地方，電(dian)(dian)(dian)(dian)池(chi)(chi)組(zu)放在窗臺里面，不(bu)要讓太(tai)陽(yang)(yang)直(zhi)射(she)為好。在晚上(shang)，由于沒有陽(yang)(yang)光，充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)為０，不(bu)用擔心(xin)(xin)電(dian)(dian)(dian)(dian)池(chi)(chi)會(hui)對太(tai)陽(yang)(yang)能(neng)電(dian)(dian)(dian)(dian)池(chi)(chi)放電(dian)(dian)(dian)(dian)，所以(yi)也不(bu)用管它。我還試過，用一(yi)個(ge)太(tai)陽(yang)(yang)能(neng)單元(yuan)(yuan)對一(yi)節(jie)電(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)，實際(ji)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)和(he)上(shang)面介紹相同。如果你用MP3，這(zhe)樣做完(wan)全可(ke)以(yi)了，一(yi)個(ge)太(tai)陽(yang)(yang)能(neng)單元(yuan)(yuan)加上(shang)２節(jie)AAA電(dian)(dian)(dian)(dian)池(chi)(chi)，一(yi)個(ge)用著，一(yi)個(ge)曬(shai)(shai)著，輪流(liu)(liu)使用，基本解決了能(neng)源問題。

    最后看一個(ge)實測(ce)充電曲線

    時間：２００４年８月２７日上午
    天氣：晴到多云。
    Ｘ軸：時間（共2個小時）
    Ｙ軸：充電電流（單位mA）
    計算得到平均充電電流：68.8mA。