Dual Battery in a 72 K20?

[72longbed]

Looking to add a battery that will be used for winching when needed. I would like to ask you guys that have done this to share ideas on location, wiring, safety, etc., please.

I would like the 'secondary' battery to be available for the winch only, but also being charged by the 100amp alternator that is in there now. I am very mechanical, but not very 'electrical', so wiring expalinations would be very helpful. I'm thinking to have the + and - leads from the new battery go to a quick connect block end, and leave it disconnected to the winch leads block end until needed?

Can a battery get over-charged if it is hooked up to the alternator and not used for long periods of time? This second battery would not be hooked into the starter ... or should I? I figure if I have two batteries under the hood, and the primary battery goes dead, I can always put the other battery in it's place. Right?

Thanks for your input 4 wheelers and winchers.

72longbed