差o左幾次 , 都以為係 13 Volt ,
今日睇真 D ........... 死火 , 會唔會乾水 ?!!

http://us.f2.yahoofs.com/hkblog/du1ni0GKHxqiCGEjWCB9MDU-/blog/ap_20070422021353845.jpg?ibAiULGBLEbknGJ5

http://us.f2.yahoofs.com/hkblog/du1ni0GKHxqiCGEjWCB9MDU-/blog/ap_20070422021346773.jpg?ibAiULGBL3PKQLHB

- ________________________ - ll

讀數冇問題！去到14V都冇問題，有好多歐洲電器都去到14V，因為好多無線電、儀錶都係用13.8V既。

斃在係 ........ 16V !!
大檸樂 ~

夏日將至，手上有一杯冰凍嘅大檸樂一啲都唔奇，我睇張相個錶都有15volt，但係舊電得唔得都唔可以淨係睇個volt數，最好係有專check電池嘅果部機，又或者托舊電去啲舖頭搵部機比人幫手check吓，試吓究竟可唔可以叉得入電。其實依家好多新款電池都唔駛點加水都可以用到死為止，但係到底係咩野問題令你覺得舊電池有事呢？問題會唔會有機會出響其他地方度？ 請詳加說明

坊間有不同種類嘅battery tester，試貼個圖和講解有關電池給大家參考

http://www.batteryweb.com/battery_tester.cfm

http://www.batteryweb.com/b300-diagram.jpg



HOW DOES A LEAD ACID BATTERY GENERATE ELECTRICITY?

A lead acid battery stores chemical energy. The chemical energy is created by the chemical action between the materials which form the positive and negative plates of the battery and the electrolyte (sulfuric acid). When the battery is connected to an external load such as a vehicle starter, the acid reacts with the battery's plates and the chemical energy is then converted into electrical energy.


THE CHARGING/DISCHARGING CYCLE

Just as in a flashlight type dry cell, the lead acid battery chemicals are consumed when electrical power is extracted. When a lead acid battery is discharged, some of the sulfate from the acid adheres to the plates and is lost or consumed. This causes the sulfuric acid to gradually lose strength. But unlike the dry cell battery, the chemical changes in a lead acid battery can be reversed by charging.

WHY DOES A LEAD ACID BATTERY GO BAD?

Age: Although charging causes the sulfate deposited on the plates to return to the acid, the process is not perfect. A small amount of sulfate insulating residue (sulfation) remains on the plates of the battery. With each charge/discharge cycle of the battery this residue accumulates. This process eventually results in diminished electrical conductivity of the plates as well as permanently diluted sulfuric acid and eventually the battery will no longer maintain a charge.

Premature Failure: One common cause of premature battery failure is loss of electrolyte due to under hood heat or overcharging. Other causes, though less common are deep discharges (leaving your lights on), using an undersized battery, undercharging, loose alternator belt, or excessive vibration due to loose hold-down clamp. Sometimes it is not just the sulfation, but the occurring mechanical damage that causes premature failure. Shorted cells, open inter-cell connectors, plate erosion and plate expansion are examples of mechanical damage causing premature failure.

WHAT IS A BATTERY'S STATE OF CHARGE?

A battery's state of charge is the open circuit or unloaded voltage across the positive and negative terminals. Under unloaded conditions, with no surface charge, a battery displaying 12.7V or above is considered to be fully charged whereas a battery displaying 11.8V or below is considered to be fully discharged.

HOW DOES A CARBON PILE TESTER WORK?

Until recently, the most effective way to determine the condition of a battery was to measure the voltage drop while draw-ing hundreds of amperes (almost a short) from a near fully charged battery. To achieve this load, large resistors (carbon piles) are applied across the battery's terminals for a short period of time (approx. 15 seconds) and the resulting voltage is read. Typically, the voltage on a good battery will not drop below 9. 7 Volts at 80°F (9. 1 V at 30°F). Although widely used, this method can permanently damage a battery, cause potentially dangerous sparks and requires an adjustment to the reading to compensate for low ambient temperatures.

我係(用第5度)差緊嘅時候嗰舊電先係15-16V呢，賣差機個老細話通常用第3度就正常架 ~ 咁我都係踎喺船上半日，咪諗住較大度數快差咯 ~

P.S. 上次呢度有師傅講過大陸差機質素麻麻，不過用一年咪試吓喔 ~

手上有一杯冰凍嘅大檸樂一啲都唔奇

手上有一杯冰凍嘅大檸樂一啲都唔奇