Could I put a relay between the power wire going from the second battery to the main battery? Then flip a switch if I kill the main battery and they will be linked to gether to start the truck and to charge the both batteries.

I do a lot of camping up north and use the headlights and the radio a lot. Last summer I killed my optima twice.

 

just my 2 cents but i'd throw that isolator in there. it will allow your accesorys to run off of one battery and not kill your "starting" battery. also some isolators will control which battery gets charged. so both batteries will not have a medium charge, it will charge your "starting" battery first then switch over to the accesory battery, an isolator is really just cheap insurance so you don't get stranded


*hey nick popular mechanic did a really good diu issue on dual battery setups with isolators, its not on their website but i have the article and im trying to upload the scans rights now


alright i have them scanned, let me know if the upload worked









if you go to my profile on photobucket i think you can zoom in a little more too. hope it helps
my profiel on photobucket: badazzblazer

 

you just had to sneek in a pic of Courtney, eh!

as for draining the batteries too quickly, you must have a s**t load of lights going.

my diesel 'Burb is wired in parallel, and the driver's side battery is grounded right to the left front corner of the cylinder head (not back to the passenger side battery). i also don't bother running a battery minder on it during the Winter while it's in storage (Nov 1st & Apr 30), and have never had an issue with it starting in the Spring.

i mention this to give you a comparison between different types of load. my garage isn't heated (has hit -15*C), and if anyone has ever started a diesel with glow plugs, you'd know what i mean by them taking a load on your batteries @ start-up. even once up & running, the voltage will drop to 9.82V when they cycle on (does this until cylinder temp is up, to ensure proper firing).

so i'd prsonally try running the batteries in parallel, before investing in expensive HD rlays to try switching back & forth between batteries. (don't remember who it was that mentioned it earlier).

 

hey dude i didn't put her there, popular mechanic did. teeeheh,
x2 on parallel, and yes diesel will drop your volts on startup even with glowplugs it takes alot to crank over. the advantage with dual battery in a gas or a diesel for that matter, you take advantage of the same volts (12) but a much bigger amp on start up. now you could wire it 24 volt but you wouldn't have any electronics left..... mines wired the same as yours chris , its just if you want 99.9% reliability its best to make it a true parallel setup, you should be fine by just grounding the battery to the frame


*those offroad lights will drain your battery down fast too if your truck is shut off

 

Its not that I have a lot of lights as a matter of fact last summer all I used were my HID headlights. They are just on for a long time and usually im not in any state to remember to start the truck until its too late and im wondering why the lights turned off. lol

 

well, i run the largest batteries i can get (1050CA) in all my trucks-almost couldn't fit that one in the '98, how long is so long that it's too late?

maybe you should consider upgrading to LED lighting for this, or a nice small Honda QuietRun generator?

just a thought.

 

theres your problem using that junk product of a battery. For every 10 optima failures i hear i only hear one ac delco fail. My stocker in my silverado finally gave out after 7 yrs last year. not to shabby ive never heard of a optima lasting that long.

for what your wanting to do the parallel hook up will work for you

 

yeah, but how much load does your truck get put on it?

anytime you start loading up the electrical system in your truck (or car), you're gonna start hurnting the batteries, even the alt is gonna come under attack.

the AC's don't have enough storage (in reserve minutes or amperage) for anything other than starting a vehicle.

 

my silverado has problably more load then many other ppls trucks unless they are a serious stereohead


i run a EWP which uses a 30amp fuse, i run twin 255 fuel pumps which both run at same time, i have 05 Efans, HIDs, 2 amp system, Meth pump. I have alot of draw and my battery is in the rear under my bed. i run the Fbody alternator and its only a 102 amp. I have no issues with drain or anything. I can be in staging lanes with key on and run my water pump and fans without much drain.

the delco is a solid battery that many dont give credit for, its a much better battery that can be recharged then the optima's. Im speaking from personal experience not just what i read off the net.

im well aware of the drain on a electrical system with upgrading of components, i have an electrical background that helps me along. the biggest thing ppl over look is size of wire. you can only supply so much with small wire. youll never fully charge a battery properly with undersize wire. Factory wire is undersized to start with

 

For independent control of the batteries:



Marine Battery Selector Switch - 4 Position Switch


Keep it on both until you park and camp, then select the primary battery that does better for long duration accessory usage, then select your starting battery when you need to get up and roll.