Use a float charger like this.

http://www.harborfreight.com/automatic-battery-float-charger-42292.html

Make sure you use the float charger after you fully charge up the battery.  The float charger is only cabable to maintain the battery voltage while it's not able to charge a depleted battery to fully charged state.

How do you measure the battery and get the reading of 12.75V?  Do you take the measurement before or after you start your car?

If before, the normal range is 12.5v -- 12.66v. Once you start the car, the battery voltage should be around 14.4v.  If it's lower than that like 13.36v, the alternator is bad.

所有跟帖： 

• 回複：Use a float charger like this. -weiyi- ♂ (6708 bytes) () 01/02/2011 postreply 16:09:28

• See my inline reply -beHappyLOL- ♀ (4841 bytes) () 01/02/2011 postreply 18:32:40

• I don't have battery charger, I just use a cable to connect anot -weiyi- ♂ (70 bytes) () 01/03/2011 postreply 08:02:55

• I just use a cable to connect -weiyi- ♂ (45 bytes) () 01/03/2011 postreply 08:04:18

• 我重複一下我的問題, 給電池充電用Cable conncet -weiyi- ♂ (78 bytes) () 01/03/2011 postreply 08:36:43