I have an old AT supply from a computer. It's a 250 W model rated at 10amp on the 12v rail. Being an old AT supply, it is powered on via a switch and does not require a load or any connections to stay on.

I read 11.97 volt with no load, but it jumps to 12.54 with a standard hard drive plugged into it.

I believe that this unit can be used to drive most chargers on the market today by simply providing a way to connect the common and +12volt leads from one of the standard 4 pin molex connectors to my charger (I plan to use bananna plugs for this). Am I correct in thinking that this will work that easily, or will more be required?

I figure there is no need to solder resistors on an AT supply, as the charger running on the 12 volt rail should provide adequate load, and an AT supply does not require a load in order to stay on. Is this correct?

If this will work it will save me a bit of money on buying a charger. I need something that will let me charge both at home and at the field, but I don't really feel like sinking the money into a 989 or buying a separate hobby 12 volt supply.