[simplechamp]

If the pack isn't specifically labelled otherwise then 1C charge rate is the standard. So 5A for your 5000mah packs. Doesn't matter if it's a 2S or 5S, current is the same. Newer lipos often state they can be charged at 2C or greater, but again, if there is any doubt go with 1C. Also, there is some question about if charging at higher rates (2C and above) affect life/capacity of the pack. I haven't followed the discussions much myself and stick with 1C, but it's something worth looking into.