Your receiver packs, transmitter pack, and glow ignitor can be charged at 1 amp. The starter box batteries will be fine with a 5 amp charge.
For the receiver packs, transmitter pack, and glow ignitor pack, you don't need alot of power out of them. Charge them through the week lower than 1 amp. Maybe 0.5 amp or lower even. I discharge my receiver packs once a month at about an amp and then charge them at 0.1amp. When I'm at the track I charge at 0.5.
If it's something you need alot of power from, charge it at a higher rate (no more than 1.5 amps for smaller batteries). If you need something to last, charge it at a lower amp rate.