Yes, that should work. I recall that the battery manufacturers prefer that you push from a slightly lower voltage than 14.8 volts if you are leaving the charger on the battery for long periods. It might be only a bit less, like 14.2 or maybe 13.8 volts, I can't recall. So if you can have two settings of voltage, that would be helpful. You can push a bit more than 200 mA for a faster charge if you want. It would be quite alright to go with 500 mA (ie. a lower value of resistor), but you might want some sort of method of lowering the current when the battery voltage reaches its peak value. Even cheap off-the-shelf car battery chargers do this.