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Discussion Starter #1
Can this be done...

Can I run dual batterys and have the added battery be charged by the alt but only run accessories and not drain the stock battery?

IE.
Can I get an optima and wire it so that it charges like the regular battery but have it so I can run lights/cbradio/amp etc.. and not have to worry about the truck not starting where if I killed it only that battery would die?

How do I do that
and where can I get the battery tray for my truck to go on the passenger side at the firewall?
 

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the tray can be ordered at gm
I have the part #'s on my home comp but I'm sure someone here has them
When I do my dual batt setup I plan on wiring a 3 way switch to a relay to a solenoid to give me off,on,auto(on when the ign is on)
the switch will be a 3way low amp toggle switch
the relay will be your standard 30 12v auto relay
and the solenoid will be a 300amp continuous duty from a rv store
 

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GMFS slowest truck :read:
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you could also buy a battery isolator to do exactly this. Run 1 wire from alt to isolator, 1 wire from each batt to isolator...it charges them but won't let them run together. They can be had almost anywhere, Ebay, some parts stores, RV stores, etc.
 

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Wanna B Jack o all Trades
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RedneckDude said:
you could also buy a battery isolator to do exactly this. Run 1 wire from alt to isolator, 1 wire from each batt to isolator...it charges them but won't let them run together. They can be had almost anywhere, Ebay, some parts stores, RV stores, etc.
yes but you get a .7 volt drop across the whole system. With a solenoid you dont get that and can still do the same
 

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OGMFS Member
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Get you a diode/heatsink type isolater like a Cole Hersey. They are design to not let the voltage drop that Forklift is talking about.I install these on ambulances!They can handle a ton of heat/abuse. If you plan on going high amp alt in the future, make shure to get an isolater rated for the amperage of the alt. It would suck to have to but another isolater in the future.I try to stay away from the relay/solenoid type isolater, Ill post a pic later and you will see why I prefer them.
 

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ratt rons right...the cole hersee unit works great with a 4-way marine switch, bat 1, bat 2, all, and off makes it so you can lock it up and not worry about theft. Go the 200 volt alt. and the 200 volt isolater from ratt ron and you will be happy. Cole Hersee recomenders their switch ( 185.00 ) but perco makes one rated at 300-350 volts that is waterproof for about 20.00 at most boat shops...ratt ron rules
 

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Rollin with Saget
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ratt ron, can u post up pics of that? lately ive been thinking of a dual battery setup. at night especially my system dims like mad. got the lights on, the stereo on, the compressors on... my voltage drops like crazy; even with the alt from u. right now i have a red top on my truck. what i would like is close to no voltage drop. that way, i can get my ac fixed, and be able to drive with the ac on and not worry about the power not being there.
 

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Why even put the batterys in the engine bay?

My mechanic was saying I should mount it on the frame rail under the truck and then just have a post under the hood for negative and positive if I need to jump the batteries. Cleans up the inside and then I can install a small terminal block as well as auxiliary fuse box. Lord knows I need it with my Strobe lights, HID lights, Led lights, fog lights, driving lights and who knows what else I'll install.

Just an option and just wondering why no one has done it yet. I cant install a second battery under the hood my Tomar strobe light power supply is there.

Dave.
 

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slamdfullsize said:
ratt ron, can u post up pics of that? lately ive been thinking of a dual battery setup. at night especially my system dims like mad. got the lights on, the stereo on, the compressors on... my voltage drops like crazy; even with the alt from u. right now i have a red top on my truck. what i would like is close to no voltage drop. that way, i can get my ac fixed, and be able to drive with the ac on and not worry about the power not being there.
Damn sorry forgot to post the pic, I'm off today so it will be tomarrow before I can get the pic up. Rob did it just start doing this?:bawl: Call me first thing in the morning I will send you a new one right out.:rocking: :head:
 

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Rollin with Saget
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ratt ron said:
Damn sorry forgot to post the pic, I'm off today so it will be tomarrow before I can get the pic up. Rob did it just start doing this?:bawl: Call me first thing in the morning I will send you a new one right out.:rocking: :head:

just start doing what? dimming? i really dont know, ive never noticed it as bad as it has been lately. but i mean when im driving at night with my lights on, comp on, and stereo on; it always has dimmed some, but mainly at stop lights.


and i dont have ur number nemore... pm me with it and ill give u shout when i get a chance... itll prolly be wednesday before i get a free afternoon
 

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Rob, pm sent.Here is a pic of the 2 isolators. The small solenoid looking thing is what Stinger sells as a isolator, most people in this bussiness call it a continuous duty solenoid.the big blue bastard is the ONLY isolator I use.
100_0478.gif
 

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Rollin with Saget
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ratt ron said:
Rob, pm sent.Here is a pic of the 2 isolators. The small solenoid looking thing is what Stinger sells as a isolator, most people in this bussiness call it a continuous duty solenoid.the big blue bastard is the ONLY isolator I use.
100_0478.gif


how much is the big blue bastard?
 

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The isolators really depend on how many amps your alternator puts out. If it is stock a regular one will suit your needs 100-150 amps and run from $50-100. For higher output alternators you will need a larger one and they wil cost more the 250 amp one that I had on my tahoe was $240 shipped.
 

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slamdfulsize: I cant post prices.:hmm:
Yukon 400: If yours is like the big blue(diode/heatsink) I could have saved you 80$ to the door.:shake:
 

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Rollin with Saget
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ratt ron said:
slamdfulsize: I cant post prices.:hmm:
Yukon 400: If yours is like the big blue(diode/heatsink) I could have saved you 80$ to the door.:shake:

word...

i swear ill call u, long day at work today, just got home a few minutes ago.
 

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I want to run dual batteries also. A red top under the hood and a yellow under the bed in the back for compressors and amps. The stinger one will work I'll just get some voltage drop? Is the voltage drop on both batteries or the second one?
 

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The voltage drop will be acoss both batteries, but if your alternator is able to supply enough power that is not a problem getting the batteries charged. Are you talking about the sr200 or the s2402? The sr200 is just a solenoid, and the s2402 is the diode type battery isolator.
 

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meow
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Hurray for thread digs!

I've thought about running dual batteries as well. I have a high output alt (thanks to rat ron :D) and just a regular battery. I want to do it for:

1. Reliability - Always knowing that it will start even if 1 battery dies
2. Lights - My lights dim and I loose volts with no stereo on :think: (pretty sure its a ground issue) but will be upgrading stereo within the next year
3. Theft - Would like an alarm system to run on a back up battery in case the connection is cut to pirmary battery.

Does anyone have a good tech article on isolators? i.e. what to look for and pricing? Or would it be simpler to just run a dual setup? I remember seeing a "dual battery kit" for chevys, but can't find anything. I already have the 2nd battery tray if your wonderin' :rolleyes:
 

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Typical Smart-Ass
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ratt ron, can u post up pics of that? lately ive been thinking of a dual battery setup. at night especially my system dims like mad. got the lights on, the stereo on, the compressors on... my voltage drops like crazy; even with the alt from u. right now i have a red top on my truck. what i would like is close to no voltage drop. that way, i can get my ac fixed, and be able to drive with the ac on and not worry about the power not being there.
Get a good 2 farad or more capacitor and it should take care of the dimming issue. I'm not saying don't run 2 batteries, it would still be a good idea. Just a thought.
 
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