has anyone here done a dual battery set up on their first gen? i've been contemplating it ever since i realized the first gens only have one battery. idealy it would go opposite of the existing battery, but that would cause problems with the air intake. it looks as though there is enough room next to the existing battery to possibly get another one in there with the proper modification. has anyone done this? got pics? throw some ideas my way!

Karsten

 

People have put two smaller batteries in the existing tray. I just run one big one, commercial style, and i've never had any problems. Had the same battery for 2 years now and it was in the truck when I got it. Who knows how old it is now?

 

I have two "REDTOP" Optimas in mine.. they set side by side on the orignal tray..just turn em sideway's..fits like a glove.

 

I run two group 31s side by side on the factory tray. They are rotated side ways and I built a bigger hold down strap. I did have to trim a bit off the inner fender lip to get them to fit.

To be honest though one group 31 battery should be more than enough for most people and fits very nicely into the stock tray. I just have almost unlimited access to used group 31 batteries and at -30C if I've forgotton to plug the truck in() it takes 3-4 cycles of the grid heater to fire up.

 

This is exactly i did too, works well, it does add a little lean towards the driverside though on mine.

 

I just put a new Optima Yellow Top D31A (group 31) in my truck. Fits in nicely. And it spins the old gal like a cowboy at a square dance. Although I think global warming has set in here in Colorado since we've only had a couple of nights that even hinted of freezing! It was a little spendy, but I hate using stuff that leaves me stranded. Any group 31 battery should be enough I think unless you're starting your truck above the arctic circle.

 

Ditto on the Optimas, I have two redtops turned sideways, just off the shelf kind, made a holddown for it, and works awesome. Eventually I would like to put two yellowtops in the toolbox out back with a switch from the charging system, for a backup 1, and to run an inverter. Be kinda cool if I had a panel with 110 outlets on it lol. would've come in handy lots of times already. But the inverters are big $$$$ so waitin for now.

 

I've have single group 31 batteries in each of my trucks, works fine.
They are still running on their second batteries,
just get a quality battery like an Interstate.

 

what exactly are "group 31" batteries?

 

It is the physical size and post rating sort of speak. there are several group sizes, i.e. 84,58, etc. If you look at batteries at parts stores they will have a number and then some letters coresponding to where the posts are on the battery.

 

group 31 batteries may come in different cranking amp capacities,
get one with the highest cca rating, 1000 amp or so.

 

How I connected mine…
I welded a bracket and installed my second battery on the right fender just in front of the blower motor. In the front I am running 2 group 31 Interstate Workaholics, they are connected to the alternator through a Sure Power isolator with a optional 100 amp solenoid in parallel to handle the possible loads. Both of the new ground cables are made from #2 welding cable directly to the engine block and a tap grounding to the body, the main battery is connected to the starter as it was in stock form but the #2 or auxiliary battery is connected through the isolator and relay and terminates at a big insulated stud before it connects to the main battery's positive terminal.
#1 = main battery.
#2 = front auxiliary battery.
#3 = rear 8-D deep cycle battery.
If you check in my gallery you see I dumped the little stock 120 amp ND alternator and replaced it with a Leece Neville 555 alternator, I now can produce 85 amps at an idle to charge all of my batteries.
In addition to the 2 batteries under the hood, I have a group 8-D deep cycle battery in the back behind the left wheel well under the camper shell. There is a single #00 welding cable from the negative to the chassis ground and the positive terminal along the frame rail to the front where it connects to another Sure Power isolator and relay and finally terminates at the same insulated stud where all batteries share a common connection on the 12-volt rail. The isolators have a smart charge so they will not conduct until the main battery reaches a certain voltage so there is always a few second delay before the auxiliary batteries get power. I had burned out about 6 stock alternators before I cured the problem and went to the 555.
The isolators have a parallel switch so you can press 2 buttons and connect the 3 batteries together for full output with a combined output of about 3800 amps so I can spin my starter till it burns out.
After I got the battery system installed I went and rearranged the power feed at the fuse panel and through the use of a number of 30 and 70 amp bosch relays I have isolated the starter and grids to be the only load on the #1 or main battery and the rest of the loads such as the lights to be on #2 that way I could leave my lights on all day till the battery went dead and still have a fresh battery to start the truck. The #3 battery in the back is for the 3000 watt inverter that supplies all of my AC power I use for work in addition to the lighting which includes 2 4' 40 watt fluorescent tubes along the top of the window on each side, these are powered by a high frequency inverter that will give you a nasty bite if you get too close to the output stud. And at the rear window I have 2 100-watt halogen work lights and a strobe.
Jim.

 

I didn't think the yellow tops would be good in our trucks. I thought they were only good for running electrical acessories like big stereos and stuff. I have two yellow tops in my garage that I guess i should put on the trickle charge and put them in then right?

 

The yellow tops are deep cycle, the red tops,,,,well although I like em, try draining one down completely and charging it again,,,ussually ruins it. Plus if you search around you can get a 3 year free replacement ussually with 5 more years of prorated warranty on the redtops where you can only ussually get a year free and 24 months or so on a yellow top. so in my understanding while the yellow top's have superior deep cycle performance, the redtops have better warranties. So for a starting battery, the redtops do just fine. If you're running a winch, or a big stereo, something that drains alot of power over an extended period of time, then you might need the yellow tops.
Someone correct me if I'm wrong, but that's how I've always understood it.

 

sweeeeeeeeeet