I have scoured the net, sites like battery university and nowhere can I find any real info on what voltage, current, charge, discharge times to create a pulse charger for a 12V SLA battery.
I have a need since after replacing my UPS batteries, I have a number of 2nd hand that I want to charge. Conventional chargers take too long.
The locally import battery chargers we get from China are expensive and they don't do what they claim should happen ie multi stage charging.
From some docs downloaded from Wikipedia and other sites, it seem that PULSE CHARGING SHOULD DO THE TRICK if high current/voltage pulses could be managed ie: magnitude, pulse rate etc. and it won't damage the batteries.
I've rewound a transformer to deliver 500V DC pulses using a 555 timer but from a previous reply from one of the senior forum members this is too high.
My question: Is there ballpark specs I can target on to start experimenting without blowing things up ? Will say a 50 - 60 volt pulse of short duration and @ 6.9A be sufficient ?
Battery Specification:
Cells Per Unit = 6
Voltage Per Unit =12
Normal Operating Temperature Range = 25oC±5oC
Capacity = 20Ah@20hr-rate to 1.75V per cell @25oC
Weight = Approx. 5.90 Kg
Max. Discharge Current = 200 A (5 sec)
Internal Resistance = 14m ohm
Operating Temperature Range = Discharge: -20 ~60 Charge: 0oC~50oC Storage: -20oC~60oC
Float charging Voltage = 13.7 to 13.9 VDC/unit Average at 25oC
Recommended Maximum Charging Current Limit = 6A
Equalization and Cycle Service = 14.6 to 14.8 VDC/unit Average at 25oC
I have a need since after replacing my UPS batteries, I have a number of 2nd hand that I want to charge. Conventional chargers take too long.
The locally import battery chargers we get from China are expensive and they don't do what they claim should happen ie multi stage charging.
From some docs downloaded from Wikipedia and other sites, it seem that PULSE CHARGING SHOULD DO THE TRICK if high current/voltage pulses could be managed ie: magnitude, pulse rate etc. and it won't damage the batteries.
I've rewound a transformer to deliver 500V DC pulses using a 555 timer but from a previous reply from one of the senior forum members this is too high.
My question: Is there ballpark specs I can target on to start experimenting without blowing things up ? Will say a 50 - 60 volt pulse of short duration and @ 6.9A be sufficient ?
Battery Specification:
Cells Per Unit = 6
Voltage Per Unit =12
Normal Operating Temperature Range = 25oC±5oC
Capacity = 20Ah@20hr-rate to 1.75V per cell @25oC
Weight = Approx. 5.90 Kg
Max. Discharge Current = 200 A (5 sec)
Internal Resistance = 14m ohm
Operating Temperature Range = Discharge: -20 ~60 Charge: 0oC~50oC Storage: -20oC~60oC
Float charging Voltage = 13.7 to 13.9 VDC/unit Average at 25oC
Recommended Maximum Charging Current Limit = 6A
Equalization and Cycle Service = 14.6 to 14.8 VDC/unit Average at 25oC