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，充電電池是四節鎳氫電(dian)(dian)池串聯。串聯一個電(dian)(dian)流表(biao)監(jian)視充電(dian)(dian)電(dian)(dian)流（100uA表(biao)頭并聯電(dian)(dian)阻(zu)改(gai)為(wei)100mA電(dian)(dian)流表(biao)）。沒有什么線(xian)路，直接把電(dian)(dian)池組和太陽(yang)能電(dian)(dian)池組并聯就可以了。

    充電電流隨陽光強度變化，在無(wu)直射的情況下，充電電流約１０多mA；

    強烈日光直射下(xia)，充電(dian)電(dian)流(liu)可以達(da)到和超(chao)過100mA。

    這(zhe)樣就行了，大家可(ke)以(yi)估算，在(zai)晴到(dao)多云天氣，每天充(chong)入(ru)電(dian)(dian)(dian)(dian)(dian)量(liang)約400-800mAh，這(zhe)樣一(yi)(yi)(yi)組實(shi)際(ji)容量(liang)2000mAh的(de)(de)鎳(nie)氫電(dian)(dian)(dian)(dian)(dian)池，３到(dao)６天可(ke)以(yi)充(chong)滿(man)。不用(yong)(yong)擔心充(chong)電(dian)(dian)(dian)(dian)(dian)問(wen)題，對電(dian)(dian)(dian)(dian)(dian)池講這(zhe)是涓流(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)。太陽(yang)(yang)能(neng)電(dian)(dian)(dian)(dian)(dian)池組放在(zai)窗(chuang)(chuang)臺外面，能(neng)曬(shai)到(dao)太陽(yang)(yang)的(de)(de)地方，電(dian)(dian)(dian)(dian)(dian)池組放在(zai)窗(chuang)(chuang)臺里(li)面，不要讓太陽(yang)(yang)直射為好。在(zai)晚上(shang)，由于(yu)沒有(you)陽(yang)(yang)光(guang)，充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)為０，不用(yong)(yong)擔心電(dian)(dian)(dian)(dian)(dian)池會(hui)對太陽(yang)(yang)能(neng)電(dian)(dian)(dian)(dian)(dian)池放電(dian)(dian)(dian)(dian)(dian)，所以(yi)也(ye)不用(yong)(yong)管(guan)它。我(wo)還試過，用(yong)(yong)一(yi)(yi)(yi)個(ge)太陽(yang)(yang)能(neng)單(dan)(dan)元對一(yi)(yi)(yi)節(jie)電(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)，實(shi)際(ji)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)和上(shang)面介紹相同。如果你(ni)用(yong)(yong)MP3，這(zhe)樣做完全(quan)可(ke)以(yi)了，一(yi)(yi)(yi)個(ge)太陽(yang)(yang)能(neng)單(dan)(dan)元加上(shang)２節(jie)AAA電(dian)(dian)(dian)(dian)(dian)池，一(yi)(yi)(yi)個(ge)用(yong)(yong)著，一(yi)(yi)(yi)個(ge)曬(shai)著，輪流(liu)(liu)使用(yong)(yong)，基本解決了能(neng)源問(wen)題。

    最后看一個(ge)實測充電曲(qu)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(ji)算得到平均充電(dian)電(dian)流(liu)：68.8mA。