Yes. If you connect a cable from the + on one battery to the - on the other, connect the charger + to the free battery terminal + and the charger - to the free battery terminal -. Obviously don't use the other battery terminals ( one + and one -) that are connected directly to the jumper.
2 amp setting is best for the batteries but 10 amp will work too.
Do you own a hydrometer? There are those here who can tell you how to get all set up and this freshening charge is the first step, but it is easier if you can measure the specific gravity of the acid.
Jim
