12v lead acid batt

[wickkerr82]

hi guys was wondering, when do you guys know that your 12v lead batt batt is low and when you do charge it how long does it take to be full and how do you know its full... does the volts show 12.5 wen full or something n does it show 11.5 wen it is close to empty. this is wat some1 told me...
can some1 help me.. thanks guys..

[Demented]

Ok... just to share some common chemistry in batts and their requirement for charge and discharge...

Lipo/Li Ion
Charge= 1C and below, charge anytime is possible or when batt falls below 3.7 volt
Discharge= try not to discharge below 3V

NiMh
Charge= with temperature control, above 5C is possible, charge anytime is possible or batt discharge to 1.2volt
Discharge= try not to discharge below 1.2volt

NiCd
Charge= with temperature control, above 5C is possible, charge when batt discharge to 1.2volt
Discharge= try not to discharge below 1.2volt

Lead Acid 12V
Charge= As often as possible
Discharge= try not to over-discharge maintain above 12 volt

This explains why car have to switch on their engine to drive the alternator to constantly charge the car batt even if u know the batt wont be over discharge... (maintaining the voltage is important for lead acid) otherwise an irreversible chemical process called sulfation will occur and the batt have to be discard... hope i didnt get the facts wrong... and hopes this helps

*the voltages are purely a guide for myself... some other user may have slight variations but the values is very close...

[wickkerr82]

Ok... just to share some common chemistry in batts and their requirement for charge and discharge...

Lipo/Li Ion
Charge= 1C and below, charge anytime is possible or when batt falls below 3.7 volt
Discharge= try not to discharge below 3V

NiMh
Charge= with temperature control, above 5C is possible, charge anytime is possible or batt discharge to 1.2volt
Discharge= try not to discharge below 1.2volt

NiCd
Charge= with temperature control, above 5C is possible, charge when batt discharge to 1.2volt
Discharge= try not to discharge below 1.2volt

Lead Acid 12V
Charge= As often as possible
Discharge= try not to over-discharge maintain above 12 volt

This explains why car have to switch on their engine to drive the alternator to constantly charge the car batt even if u know the batt wont be over discharge... (maintaining the voltage is important for lead acid) otherwise an irreversible chemical process called sulfation will occur and the batt have to be discard... hope i didnt get the facts wrong... and hopes this helps

*the voltages are purely a guide for myself... some other user may have slight variations but the values is very close...

thanks demented, i really appreciate the help, wil charge the lead batt as often as possible. greatly appreciate ure help. thanks again buddy.

cheers..
vin

[Demented]

hey no prob... iz my pleasure!!

[mathsinstrument]

The operating voltage is from 12-13V. To check what is left in it, use a multimeter and test for it's resting voltage. Eg: 12.4v = 40% left

[hosch]

hi guys was wondering, when do you guys know that your 12v lead batt batt is low and when you do charge it how long does it take to be full and how do you know its full... does the volts show 12.5 wen full or something n does it show 11.5 wen it is close to empty. this is wat some1 told me...
can some1 help me.. thanks guys..

The following table can be used as an approximate guide:

12.7V - 100%
12.4V - 75%
12.2V - 50%
11.9V - 0% (I've seen around 11.7V on mine though )

Keeping the battery at full charge will prevent a process called sulfation from decreasing the maximum capacity of the battery. The charging duration depends alot on the charger and algorithm used but 3-5 hrs is quite normal for a reasonably good charge..

Check out the following for more info:
http://www.batteryuniversity.com/partone-13.htm
http://en.wikipedia.org/wiki/Lead-acid_battery