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Adding a 2nd battery

mz

Full Member
Joined
Dec 8, 2011
Messages
20
I have been having some battery issues not quite resolved yet, but it made me think that I could rig up a 2nd battery so I wouldn't get stranded anywhere. I would like to put all electronics of the truck on a 2nd battery and run my main one just as a starting battery. I have 2 batteries and a stinger sr200, and all the wires.(from an my bass days). How would I hook this up? 2004 Chevy avalanche z71.
 
There are lots of posts about adding a second battery. There is a kit made by Painless that has the wires and connections you need and several members have used that kit to do their setup. You can probably even find photos in the older posts too.
http://chevyavalanchefanclub.com/cafcna/index.php/topic,47730.0.html This old thread has info and photos.
 
Is this a good idea? I was gonna place my starting battery in the new location (passenger side) and route it straight to the starter and alternator, then where the original battery was I would place a deep cycle battery with it hooked to the electrical system like normal and then go to a singer sr200 to get charged while the truck is running, and tie the batteries together. I thought this would be a great way to separate the 2. Will this work properly? Any problems with doing it this way?
 
mz said:
Is this a good idea? I was gonna place my starting battery in the new location (passenger side) and route it straight to the starter and alternator, then where the original battery was I would place a deep cycle battery with it hooked to the electrical system like normal and then go to a singer sr200 to get charged while the truck is running, and tie the batteries together. I thought this would be a great way to separate the 2. Will this work properly? Any problems with doing it this way?


It will work.. That's how the Painless and Wrangler aux battery kits tie the batteries together in the stock location with a 200amp solenoid. Your just reversing the location of the batteries, just make sure you move the power cable that goes to the fuse box to the main battery. You can do this by connecting it into the red J-Box that the alternator goes to now and running a another cable from the stinger sr200 to the aux battery.

This is also a good time to up-size the main cables and run extra grounds to the frame and up-size the alternator charge wire, AKA the Big 3.


Edit.. Also you may want to put in 2 new batteries that are the same. When connecting 2 batteries together you typically want them to be the same type and age..
 
is it not good to keep the fuse box off of the main battery? I was thinking of doing it that way so that nothing but the starter and alternator would be on the main(starting battery)
 
It will work either way.. But depending on what you plan on running off the aux battery it could cause problems. If you run down or isolated the aux battery for any reason the ECM would be looking at the wrong battery and your voltmeter would be off. IMO you should keep the fuse box on the main battery..
 
Whatever you do make sure you ground both batteries to both the frame and the engine block....

Normally a second battery is used to run additional equipment and leave the original battery in place to run everything else. You CAN run into issues with voltage differences in your vehicle if you don't do something right.

Always make sure your alternator is hooked to a battery... It uses the battery to smooth out the output and you can cause serious injury to components due to voltage spikes without it.

You CAN do as suggested and add a second battery that can give you a jump if your main battery dies... You can also get a "battery buddy" that enables your battery to disconnect its self if the voltage drops too much.

Just realize you want your secondary battery to be fully charged if you use it to jump your truck. When you parallel two batteries it can make the internal resistance higher making it harder to start the truck if at least one of the batteries is not fully charged.

I have two batteries in my truck and I only use the second one to run my amplifiers and computer. (As in PC)
 
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