Hi,
I am looking for a circuit/device that will charge a 12 V 7 A h EnerSys battery from a 24 V ac line. Any advice would be greatly appreciated, the current levels from the 24 V ac line will be 10 - 15 A (max), but will be passing into other loads as well. We are building a ac network with a couple of sources, resistive and inductive loads as well as battery storage.

Thanks,
Don

 

24VAC will have 33-35 volt peaks on the AC. You could just make a simple full wave Bridge and charge the batteries (connected in series as 24 volt batteries). This would have to be watched carefully or have a timer to disconnect the batteries after x amount of time.

 

Thank you for the advice, our line will have a peak of 24 V ac. We were also considering using a full bridge rectifier and a solar charger. I'm not sure if this would be feasible though. Any suggestions would be greatly appreciated.

 

The battery should be charged up to 14.7v at no more than 1.75A, which is 1/4 the AH capacity, and then float-charged at 13.7v.

This is assuming that the battery internal temperature is maintained at 25°C/77°F.