I got a Kodak zi6 camcorder, and it came with rechargeable batteries and a mini wall charger. The charger model is K630. Will this kind of charger shut off automatically when the batteries are fully charged? If not, how long should I charge the Kodak rechargeable batteries so I don’t overcharge them?

The Instructions for this charger can be found here:

http://www.kodak.com/global/plugins/acrobat/en/service/manuals/accessories/K630_en-US.pdf

It looks to me that once the batteries are charged fully it will turn off, however, to be safe and to maximize the life of your battery I would advise to remove them once they’re full either way…

Maybe a Batteries Plus store could find out for sure what happens once the charge is completed… there might be a store near you:
http://www.batteriesplus.com/t-storeloc.aspx?m=ya