Battery charging
Battery charging
(OP)
I was just wondering, could you charge a lead acid battery using a power supply.
Example, I have a standby generator at one of my stations, it is diesel and uses two 12-volt battery’s in series to make 24-volts. The 4-amp battery charger has gone out, can I use a 24-volt power supply to charge and maintain the batteries? I am going to use diodes to keep the generators, alternator from feeding back into the power supply when it is running. Will I have to up the voltage to 26-volts to over come the internal resistance of the cells so they will charge or can I leave the voltage at 24-volts.
Example, I have a standby generator at one of my stations, it is diesel and uses two 12-volt battery’s in series to make 24-volts. The 4-amp battery charger has gone out, can I use a 24-volt power supply to charge and maintain the batteries? I am going to use diodes to keep the generators, alternator from feeding back into the power supply when it is running. Will I have to up the voltage to 26-volts to over come the internal resistance of the cells so they will charge or can I leave the voltage at 24-volts.
RE: Battery charging
You seem to be knowing the answer. Yes, you are right, you need more than 24Volts supply to charge a 24V lead acid battery. To maitain the battery in fully charged condition (by making up the losses), it is recommended to maintain a voltage of 2.23 to 2.25 volts per cell at the battery terminals.
RE: Battery charging
Steve Owens
Finish Line Product Development Services
www.FinishLinePDS.com
RE: Battery charging
Steve Owens is correct in that if you want a faster charge on your batteries you need a dedicated charger. The "float charger" he mentions is faster than a 'trickle charger' (basically the 'maintenance' method described in the first paragraph) but slower than a fast charger.
I hope this isn't too confusing, but what it boils down to is that if the demands on the batteries are 'light' (few operations with long intervals between) the 'maintenance' or 'trickle' charge will do. If this can't keep the batteries 'topped up' then you need to go with a 'float charger' or possibly even a fast charger.
RE: Battery charging
RE: Battery charging
If you're only concerned with trickle charging then you could use a supply of suitable voltage - the required voltage does vary with temperature but unless the batteries are exposed to large variations t should be possible to find a reasonable compromise. (there's a table of volts against temperature (for sealed lead-acid batteries)in http://www.powerstream.com/SLA.htm.)
If you could adjust the power supply to a rather higher voltage (say 32V or more) there are more possibilities, depending on how much trouble you want to go to - I've seen circuits for chargers that will sense battery current/voltage and control the charging rate appropriately - for example I came across one at http://www.uoguelph.ca/~antoon/gadgets/labc2.htm (though like most of the ones I've seen it's not intended for 24V so would need modification.
Good luck!
Mike
RE: Battery charging