Connecting AGM battery(/ies) to engine

[Indyflies]

[font=Tahoma, Verdana, Arial, sans-serif]Hi all - I'm getting there on my 2006 Chevy Express 3500 passenger van conversion.  It came with a single separate Group 31 AGM battery which powered a fan, some lights and an outlet.  I'm installing a fridge and need the usual outlets and usb connectors to be able to work on my laptop on the road.  I was thinking of getting a second battery, but my main questios is this ... how do I connect the battery to the engine so it's charged from the engine as I drive?  I'm not getting solar at this point, though maybe a suitcase panel.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]The chap I bought it off suggested taking the power from the aftermarket hitch and rerouting it.  That wire is plugged into a 20A fuse in the fusebox under the seat (pic attached). I don't know what gauge that wire is.  I've currently disconnected everything. including the fuse, so can start from scratch.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]Here's what I've learned is the order:[/font]

[font=Tahoma, Verdana, Arial, sans-serif]Engine >>> fusebox >>> fuse >>> isolator >>> battery | battery >>> breaker/fusebox >>> fuses >>> fridge/fan/outlet/whatever[/font]

[font=Tahoma, Verdana, Arial, sans-serif]Is that correct?[/font]

[font=Tahoma, Verdana, Arial, sans-serif]So ... two questions.  Can i just replace the current wire coming from the 20A fuse with the appropriate gauge wire (and what would that gauge be?) and 2) What isolator should I get?  I understand there are different flavors.  I don't want to have to remember to shut it off.  [/font]

[font=Tahoma, Verdana, Arial, sans-serif]Thank you all, and please forgive me for the noob qs.  I have never studied electricity, except perhaps in middle school. And besides, that was in a  240V world.[/font]

 

[bullfrog]

Since you are starting from scratch you need to determine how many watt hours you will need. Only then will you be able to determine how large a battery bank and how much charging capability you will need. Unless you are driving several hours a day you stand a good chance of destroying your batteries if you are not able to fully charge them on a regular basis. Usually vehicle charging is just used to assist in bulk charging. When I first started out I simply added a battery using heavy cables and as I was driving usually 8 hours a day figured it would be enough. I ended up buying two new batteries. Which is something else to consider as batteries last much longer if they are the same age and have the same charge capabilities.