Adding a Second Battery

[Central Toast]

I thought I might add a second AGM battery to my new to me Hawk. I've researched wiring two 12v batteries in series and it is pretty straightforward, so I don't see any reason not to add a second battery. Are there any issues that I should be aware of? E.g., would the alternator not charge this many batteries, does it put too much into the camper's system, or??? Thanks for the help.

 

[MarkBC]

Are you trying to run your camper at 12v? If so, then you need to connect them in parallel (i.e., connect the + to + and - to -), not in series, so that you double the amp-capacity, not double the voltage.
I have two camper batteries (connected in parallel), and there are no issues.

 

[Accrete]

There are a handful of ways to connect 2 x 12 v AGM batteries up for a 12 volt system... I rewired mine to a more robust setup as seen in these shots:

Stock wiring (sorry didn't take a photo of rig before my mod):

My Mods:

note how the two positive leads go into this fancy little junction box i picked up at a car stereo shop:

Now both AGM batteries are isolated from one another with 60 amp fuses in that clear junction box.
And as you can see in the upper photo of my mod the negatives of both go onto a bar.

And more at this link of my build.
Best wishes on your adventures!
Thom

 

[Central Toast]

Aha..and that is why I asked! I've exposed my elictrical ineptitude. Thank for the replies! I'll post my parallel setup when it's done.

 

[Central Toast]

And my speling ineptitude.

 

[JHanson]

The vital factor if you're going to install a second battery is to make sure the system regularly gets a full charge, either from your alternator, a PV array, or a combination. Nothing kills a battery as quickly as consistent undercharging.

 

[Riverrunner]

Does anyone use a something like a Guest charger? http://www.marinco.com/product/10-amp-dual-battery-chargepro-charger

I use one of these in my boat that has two - GP34 AGM Marine batteries. I leave the the boat pluggled in all of the time when not is use. I switch between the batteries using a sea blue battery selector switch which keeps them isolated from each other. I run off one battery at a time, so I always have one that is in "reserve". Is there any reason this setup wouldn't work on a FWC? Or will the way these campers are wired, screw something up?

What I like about the Guest is that it's a smart charger so leaving it plugged in won't hurt the battery unlike a regular RV convertor. On my last camper, I had to replace the convertor so I replaced it with an Inteli-power so I could add the "charge wizard". This allowed me to leave the camper plugged in all of the time and the battery was always fully charged. Maybe since most don't stay in one place very long, it's not an issue.

Charge wizard:

http://www.progressivedyn.com/charge_wizard.html

 

[craig333]

I have a smart charger I try and plug in now and then but since the truck is a daily driver its not too often. I keep forgetting to check the in the afternoon when I leave work to see what the solar is doing now.