Is an AC battery charger effective for charging batteries?

[NotoriousNick]

AC battery charger?

Is there such a thing as being able to charge a battery, using alternating current, or would the sweeps invariably be ineffective in giving a charge to the battery?

 

[Redbelly98]

As you suspect, that would be ineffective. But adding a diode that conducts in the appropriate direction would probably solve the problem. (We would need to see a specific circuit example in order to give a more definitive answer.)