Dual Batteries installation.

I waited till my old battery started to fail so I could install a second battery.. I have heard pros and cons about using electronic dual battery kits that are very expensive and I have seen a lot of vehicles with dual batteries hooked up in a parallel configuration with out those kits. There are a lot of factory vehicles that do not use the kit or any isolation kits. I have done this with several chevys in the past that went well over 250,000 miles with no problems and I installed this one 3 weeks ago.

Set up is very easy on the front right side looking under the hood there is a battery tray the factory installed but never used.

Parts list

• Battery hold down and bolt. You can get them from an auto parts store or the dealership it is the same part used for your existing battery
• Two new batteries. It is best if you replace both batteries at the same time.
• 36 inch negative battery cable.

• 65 foot positive cable.

1. Installation is pretty easy replace the old battery but do not attach the cables yet.
2. Install the second battery in the front battery tray and bolt it in.
3. If you have any large draw items like a winch or big stereo system you should attach it to the second battery.
4. Attach the 6 foot positive cable to the original battery block be sure to attach it to the battery side of the fuse block.
5. Attach the other end of the cable to your second battery you can run it along the fire wall or across the top of the motor.
6. Attach the negative cable to an empty bolt hole on the cylinder head
7. Both positive cables should be connected now if you didn't already so, it is time to attach both negative battery cables to their respective battery posts.
8. Re check all connections to be sure they are tight and you are ready to go.

In the future I may install a cut out switch that will cut the power from the main battery when I run my winch or decide to run a stereo and lights when camping so the other battery will be unaffected.

Love duals. Factory parallel setup on ssvs, ppvs is both positives goto starter and neg from second to alt bracket. Thats how i did mine. But yours works.

wrong way in my opinion but it's functional

Doubeleive said:

wrong way in my opinion but it's functional

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Why is it wrong to you?

It is the same way hundreds of factory units have been done for as far back as I can remember.

1. This method doubles your available cranking amps
2. Spreads the draw over two batteries instead of one taking twice as long to kill a battery.
   
3. Lengthens the battery life of both batteries dramatically.
4. Allows for an isolation switch to be installed between them if you want to later.
5. Very simple to connect or disconnect.
6. Either Battery can be pulled out of the parallel allowing it to run as a single unit by just disconnecting a negative cable. This would come in handy if one battery shorts out because with a simple disconnect the bad battery can not affect the good one.
   
7. Costs $400 less than a system that can not do some of the above.
8. If you want you can install an isolation switch in the dash too.

Tozan said:

Why is it wrong to you?

It is the same way hundreds of factory units have been done for as far back as I can remember.

1. This method doubles your available cranking amps
2. Spreads the draw over two batteries instead of one.
   
3. Lengthens the battery life of both batteries dramatically.
4. Allows for an isolation switch to be installed between them if you wan to.
5. Very simple to connect or disconnect.
6. Either Battery can be pulled out of the parallel allowing it to run as a single unit by just disconnecting a negative cable.
7. Costs $400 less than a system that can not do most of the above.
8. If you want you can install an isolation switch in the dash.

Click to expand...

the positive power wire should not go over the top of the engine it will be subject to lots and lots of heat and if there was a fire for any reason it's going to quickly become a electrical fire on top of it, it may also cause electrical interference (not likely but possible if not properly shielded), it should go either under the rear of the engine or be routed along the firewall. I don't think you going to see a manufacture run a main power lead in that manner it is dangerous. however unlikely something could happen its just not a good idea.
the oem wire for a second battery setup runs under the motor and attaches to the starter linking the two battery's together and providing more CCA.

Doubeleive said:

the positive power wire should not go over the top of the engine it will be subject to lots and lots of heat and if there was a fire for any reason it's going to quickly become a electrical fire on top of it, it may also cause electrical interference (not likely but possible if not properly shielded), it should go either under the rear of the engine or be routed along the firewall. I don't think you going to see a manufacture run a main power lead in that manner it is dangerous. however unlikely something could happen its just not a good idea.
the oem wire for a second battery setup runs under the motor and attaches to the starter linking the two battery's together and providing more CCA.

Click to expand...

I agree it could have been run better as you stated BUT... I am in Green river Utah population 900 people right now. The only store within a 100 miles did not have a longer Positive cable or I would have run it differently... I will run a longer one along the fire wall when I get back to civilization... lol

The hazards as you mentioned above are speculative at best and a battery cable would not cause any electrical interference. Connecting the batteries to the starter could give more cranking power but, it would be very negligible at best.

In my opinion it will also make it more difficult to isolate into separate systems later. This way allows an easy hook up for my winch and off road lights and other accessories so, I am not cluttering up the main battery connection. This is also much easier to install because I don't have to crawl underneath to connect to the starter... I will admit crawling under mine is very easy compared to getting under a stock one but hey I am an old man. lol

But, thanks for your input.

I've had the exact setup for over 7 years. Same batteries, knock wood. Wires over the engine and I live in Vegas so fires, none. I have a 1800 watt system. I've heard you need isolators, you need a solenoid and blah blah..glad you put fuses though. Great job

My 6.5 Turbo diesel has the second battery lead going over the fan shroud. Ive also seen Ford and Dodge run them like that on Diesel trucks. Personally, i think your setup is just fine

For the last 6 months since I bought this truck, I have been using the empty second battery location for food runs transporting Jack in the Box etc so it stays hot and doesnt smell up the rig.
Gonna lose that when my battery dies and I replace with 2 new ones and cables......waiting for battery to die......

gpracer1 said:

For the last 6 months since I bought this truck, I have been using the empty second battery location for food runs transporting Jack in the Box etc so it stays hot and doesnt smell up the rig.
Gonna lose that when my battery dies and I replace with 2 new ones and cables......waiting for battery to die......

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Lol, really? I've never even thought of that before. I wonder what people must think if they see you putting food under your hood! I can relate tho.