Set your mV/c to the lowest setting it will take to start. (.02 I'm assuming) 6 amp charge. After it detects the peak feel the pack with your hand. If its warm to the touch, definitely NOT HOT... just warm. Your good to go. If not, step up the the next lowest. .03 or .04
Being that these are stick packs you may find you have to turn up your mV/c setting as they get older to keep that temperature in them when they peak. Reason being you can not equalize them.
Dont worry about this though. For your situation, I think the person who sold you this equipment was spot on. When the kids start racing, then you can worry about being up to date with the latest battery technology!
Until then - cheap stick packs = low dollar fun for the kids.