That is hard to explain without knowing what
features the charger has. Normally, there is a switch that you can select deep cycle or standard. Naturally select deep cycle. Next choose the charging amps (2, 12, or 24). 2 is the slowest but strongest. 24 is the fastest but the weakest. You should use 2 amp if this is the first charge or if the battery is dead. Use the others for regular repowering. There should also be a voltage switch. The battery label will tell you which voltage you have (probably 12 volt). Now once the proper settings have been selected and the cables are positive to positive and negative to negative, plug it in. There should be a status light that blinks or stays continuously lit, or maybe the light doesn't come on until it is done.....anyway, keep an eye on it and watch for changes in the status warning.A 2 amp can sometimes take overnight to charge fully (6-8 hours ). The main thing to do is to check the charger periodically for any change.