原帖由 小步 於 2007-1-30 13:23 發表
4組獨立,但不是平行差
只是獨立充電, 沒有平行功能.....
基本上4組獨立沒有連接的, 不只是 esky , 3e 及出面很多自稱平行充也是.
電路比較簡單而只可盡量做到 4.20v,就算3節電池充滿但因電壓及內阻日久使用而差 ...
先不討論"平行差" 的定義,因為并沒有公認的答案.大部人接受"組獨式"和"消耗式"都是"平行差", 有執著的更認為"獨立式"才是"平行差" (refer http://www.hiphingashtray.com.hk/cgi-bin/LB5000/topic.cgi?forum=16&topic=1752&start=12&show=25). 但較小聽"消耗式/串充"才是"平行差"
至於為何間單亦能差得好,那就要先明白鋰電的特性.基本上只需要準確地測出電壓,加上有topping便可.這點"平行差"比較優勝.以"消耗式"pc5 或 pb5 balancer來說,它的誤差準度就大於0.2v.
refer http://www.batteryuniversity.com/partone-12.htm
"Battery experts agree that charging lithium-ion batteries is simpler and more straightforward than the nickel-based cousins. Besides meeting the tight voltage tolerances, the charge circuit can be designed with fewer variables to consider. Full-charge detection by applying voltage limits and observing the current saturations on full charge is simpler than analyzing many complex signatures, which nickel-metal-hydride produces. Charge currents are less critical and can vary. A low current still permits proper full charge detection. The battery simply takes longer to charge. The absence of topping and trickle charge also help in simplifying the charger. Best of all, there is no memory but aging issues are the drawback."
"內阻"是另一個問題, 基本上是由於電本身的質數,使用及年期,是不能改正的. 所以不要被誇大的廣告所誤.
refer http://www.batteryuniversity.com/print-parttwo-32.htm
"Non-Correctable Battery Problems"
Some rechargeable batteries can be restored through external means, such as applying a full discharge. There are, however, many defects that cannot be corrected. These include high internal resistance, elevated self-discharge, electrical short, dry-out, plate corrosion and general chemical breakdown."
基於以上,除了串充/"消耗式"可以較經濟地做出高cell數的差機,"獨立式"是比較優勝.
[ 本帖最後由 spree 於 2007-1-30 23:32 編輯 ] |
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