I don't know much about that charger, but in general, the best advice is to not charge over 1C which would be .6 amps and do that for an hour. Any less will simply take longer and will NOT damage the battery.

The best discharge rate would be .1C or 60 ma for as long as it takes to discharge it. The problem is that you don't know where the battery is right now. It would really help if you had a charger with a cycler. That way the discharge would be to what the cycler rate would be, and most of those are adjustable, but would discharge to a minimum level then go right into a re-charge cycle.

One charger that I have in mind is the Accucycle by Hobbico, although there are plenty others. And, there are plenty of people that will give you the "recipe" for a home-grown discharger.

Depending on how old the battery is and how long it's been sitting around, it may be alright to charge it and use it, however, what would be better would be to cycle it and see what it will truly hold. The best solution would be to simply replace it with a new battery pack if you don't know anything about it. 4 cell packs are very reasonable in price. And, that way, you could get one with a higher capacity.

CGr.