hi there,

i bought the same charger a few weeks ago, instructions don't realy help with the basics, i guess they expect you to know what settings you need already.

if you want to charge any pack you just set the batt type, amps and start charging, it will stop charging when it thinks it's full so i don't think you can over charge? but if you choose too high a amp rate you could damage or shorten the life of your batts.

i was advised not to charge over 1C, in your case 1.4A. but sure you can if need be. and as dave said the slower the better for your batts.

i started a thread on charge and discharge rates that might help.
[link]http://www.rcuniverse.com/forum/m_6205481/tm.htm[/link]

it is a great charger once you work out what settings you need.