香港快意討論區 » RC版 » [無撚聊整] 大電流放電 - 構思中

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AbarthJoe發表於 2011-7-10 14:10 | 只看該作者

[無撚聊整] 大電流放電 - 構思中

DIY 一個大電流放電.  放落仔度玩 / 放一定最快.  但係, 唔係次次都可以玩得晒差好既電.  希望方便玩唔晒 d LiPo 電既時候, 番到屋企可以早 d 做完 Storage, 早 d 訓覺.

一般 B6 charger 只有 1A 放電.
靚靚 0730i 都只有 5A 放電.

我打算用燈泡黎放.

12v H4 燈泡 55w/60w 應該可以做到 (60W+55W)/12V=9.6A
唔知用黎放 7.4V battery pack 會去到幾多 A?  要起個 lab 度度佢至知.
一個唔夠用兩個, 兩唔唔夠用夠三個.

另外想一想點樣 cut-off.  簡單 d, 買個現成既 BeepBeep 插落去, set 6.8v 或 3.4v (單 cell) 響.  到 volt 佢響就手動停放.

最 ideal 就整到可以 check 到單 cell 3.4v 就自動 cut.  不過, 遲 d 先啦.

兄弟們, 有無其他提議?

Rank: 8 Rank: 8

2^#

Simon發表於 2011-7-10 21:31 | 只看該作者

一定要有個開關制如果唔係個插一定熱到辣手.
同有個Amp錶, 可以睇住走緊幾多A, 如果有timer仲可以乘埋A x (t) hr 計個mAh添.

逢星期日...糕-糕-糕.

Rank: 10

3^#

romeochris發表於 2011-7-10 23:10 | 只看該作者

i used to have a 10 12V light bulb, I copied it from DEANS design and also had a DEANS Black BOX II!Anyone know what I am talking? haha...

Rank: 10

4^#

AbarthJoe發表於 2011-7-12 16:41 | 只看該作者

抄考下人家的作品先.

http://www.helifreak.com/showthread.php?t=277056

Rank: 10

5^#

bobby發表於 2011-7-12 17:04 | 只看該作者

不如買套cheap cheap電變同摩打用來放電咪得lo

Rank: 8 Rank: 8

6^#

Simon發表於 2011-7-12 17:56 | 只看該作者

本帖最後由 Simon 於 2011-7-12 21:47 編輯

我覺得, 用放電去推風扇, 將之吹住大火數電阻加大heat sink, 有amp錶睇住電流, 再加個大火數volume制控制電流.
目標amp數係 10A.
我們的lipo有6000mAh, 即係以6A放一個鐘就乾塘.
不過, min volt要維持在3.2v per cell, total 6.4V.
由8.4V fully charged 放去6.4V, 即係有1420mAh要散功, 所以, 如果以10A去出火, 8.52min就可以了.
唔知啱唔啱.

似乎我的理解有D錯.

逢星期日...糕-糕-糕.

Rank: 10

7^#

raypoon發表於 2011-7-12 18:23 | 只看該作者

回復 6# Simon

有個問題.....感樣放電 , 你肯唔肯定兩cell電會放得Balance??

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8^#

AbarthJoe發表於 2011-7-12 18:51 | 只看該作者

回復 7# raypoon

唔 balance 既話, 插去部差機做 Storage/Balance 得唔得? 平時玩車舊電都未必放得 balance.

呢個做法應該慳時間過由頭到尾係部差機度做 Storage?

Rank: 10

9^#

AbarthJoe發表於 2011-7-12 18:52 | 只看該作者

回復 5# bobby

都好喎, 個然係 "無撚撩" 大師兄... 不過, 搵咩做 loading 好呢? 空轉唔食電.

Rank: 8 Rank: 8

10^#

Simon發表於 2011-7-13 07:46 | 只看該作者

用電變都唔可以全自動, 除非用埋橡筋.

逢星期日...糕-糕-糕.

Rank: 10

11^#

AbarthJoe發表於 2011-7-13 09:58 | 只看該作者

本帖最後由 AbarthJoe 於 2011-7-13 09:59 編輯

回復 10# Simon

原來有手動控制器，full 雞都無問題。

http://tw.myblog.yahoo.com/robot ... &l=f&fid=10

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12^#

Simon發表於 2011-7-13 22:24 | 只看該作者

本帖最後由 Simon 於 2011-7-13 22:27 編輯

卒之求其整左個55W12V H1燈胆去散功.
1分鐘可以消耗0.07V, 8.4V 到7.6V storage, 應該只要11分鐘.

逢星期日...糕-糕-糕.

Rank: 10

13^#

佐治仔發表於 2011-7-13 22:30 | 只看該作者

卒之求其整左個55W12V H1燈胆去散功.
1分鐘可以消耗0.07V, 8.4V 到7.6V storage, 應該只要11分鐘. ...
Simon 發表於 2011-7-13 22:24

成唔成功?

Rank: 8 Rank: 8

14^#

Simon發表於 2011-7-13 22:36 | 只看該作者

ok 喎.

逢星期日...糕-糕-糕.

Rank: 10

15^#

coupeelvin發表於 2011-7-15 00:41 | 只看該作者

[無撚聊整] 大電流放電 - 構思中

Should go for active cell balancing.
But why u need to discharge the batteries except that u want them to be balance charged?

- 發送自我的 iPhone 大板凳應用

Rank: 10

16^#

AbarthJoe發表於 2011-7-15 01:37 | 只看該作者

本帖最後由 AbarthJoe 於 2011-7-15 10:35 編輯

Haha, our expert show up finally, thank you

Sometimes, I get prepared for a race, charged all packs but it was cancelled finally (e.g. rainy) , since LiPo packs not likely to be stored in full charged condition (4.2v/cell), then I have to discharge them to certain level / voltage (3.8v/cell) shortly, to avoid LiPo packs failure or become balloon.

Yes, ideal case is doing charge / discharge with active cell balancing, that's the function provided by those powerful chargers. But the discharging rate is relatively low compare to the batteries discharge ability (charger: 5A vs battery 4000mAh 40c, 160A). That's why i want a large current discharger

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17^#

coupeelvin發表於 2011-7-15 09:35 | 只看該作者

I see.... just make a simple voltage comparator circuit to switch a Relay. Then you can stop discharging at your desired voltage.

BTW, light bulb is a good choice for power dissipation.

Rank: 10

18^#

romeochris發表於 2011-7-15 11:34 | 只看該作者

In the old day when NiCd and MiMh was popular, we would use 20A (even 30A)to discharge a pack or Cycling the pack, it was not due to shorten the discharge time, it was due to the memory effect on the battery. All the racers said that they would like to discharge or cycle the pack by higher amp to simulate the real situation on the track and the battery somehow will perform more punch! By since the LiPo batt. could release almost unlimited amp. (higher C pack), we seldom use high amp. to discharge them now. By the way, the hyperion DOENST have a charge mode called Balance Charge as on B6, since every they only provided Balance charge mode on the charger.