I will never use another delco. Its not that they aren't good quality its that they have very little reserve time. You leave the radio and the headlights on for an hour and is completely dead. Wont come close to starting the truck. My optima will last a few hours. Oh btw I work at a GM dealer and replace a delco battery almost every week.

 

maybe you have a drain issue on your truck? ive been in drive ins where radio is on for a few hours no issues. However this is off topic from the orignal post.

 

absolutely on the wire gauge-especially with a relocated battery. but i wouldn't say the factory stuff is undersized to begin with, it's just not designed for anything extra to be asked of it.

while i'm not trying to start a pissing match with you, i wonder how the load of your electrical system (which would be running under the conditions you described) compares to the long drain the OP is having put on his while he is parked. while my Dart doesn't have a computer in it (more electrical drain) or a Methanol system, i do know where you're getting @ with the fuel pumps & efans.

he also doesn't mention how many lights he's running when this occurs, or a time frame.

 

Just a thought and may look into this for my own use.

Has anyone ever used or thought of using a deep cycle battery as a secondary? These do not have the cranking power to start am engine but do have the capacity to run electrical items for long periods of time. Combined with an isolator, may do the trick.

Apologies if this has already been suggested....did`t read through the whole thread.

 

Please read through the threads before posting. I dont want to use an isolator also deep cycles are fine for starting. Thats what optimas are.

Now back on track. I think I have decided to use two big solenoids. One on each battery. I know i can wire it with two separate switches but I would like to be able to keep it on one toggle if possible. I think I can do it with a few relays but im not sure on how to wire them in. Any ideas

 

Summit Racing Dual Battery Control Harness

Maybe check out some pre-made kits and use that to figure out what parts and stuff to use? Maybe check the installation instructions?

I know you dont want to use separate switches..but what was wrong with the marine dual battery switch? Are you trying to stay inside the cab to switch (solenoids) as opposed to opening the hood to switch or where you mount that manual switch?

 

not all optimas are deep cycle, the red tops are automotive batteries, the yellow tops are the deep cycle.

i run a red top in my lowrider does fine running my 2 12v compressors, i'm going to add a second one in the back though because the volts do drop if i play with the switches alot and run the compressors for awhile.
I'm just going to ground it to the chassis and connect my power wire to it and run it in parallel

 

Yeah, I looked at a few kits including that one. They all seem to switch on/off the second battery. So basically Im doing the same thing but on each battery. I looked at those marine switches but I want something in the cab. Those would be to big and hard to hide and have it accessible. So I might just have to use two switches and make sure they dont both get turned off while driving.

Another question I had was how many amps does the solenoid have to be ratted to. i have a 145amp alt but I know im not drawing that many amps. Would an 80amp for each battery be good enough or do I need to go bigger?

 

I have no advice for your particular question, however, your idea has sparked my interest. In the past, I have ran a dual battery set-up in one of my full size trucks, but they were both hooked up to totally seperate alternators. (One to operate the trucks standard operations and the other one ran all the lights, winch, stereo, c.b., etc.) My question is, what model of Blazer is this set-up going in and where are you planning on mounting the second battery? Just being curious.

 

Its going in a 99 2dr. Im mounting it in one of the side compartments.