Dual Battery

[loulblades]

The isolator (solenoid or diode type) should be sized to handle the alternator.

I have a 190A alternator and am using a 200A isolator. Not that the second battery will most likely see that much, but I guess that will depend on when I stop adding lighting (spot lights etc) and what I want to have turned on at the same time.

When I originally sized things for the second battery I was going to be adding an electric winch. Since I changed to hydraulic, the sizing is not as critical but I still wouldn't use an isolator that couldn't handle the alternator.

 

[Goebz]

If I recall correctly, and I can confirm this in the service manual, the OEM dual-battery setup just paralleled the batteries.

Here's what I used:

http://www.powerwerx.com/emergency-vehicle/battery-integrator.html

Can you post the page from the service manual that shows how to mount the driver's side tray? I bought it from the dealer and looked at his pic on the computer. It is supposed to go OVER the Evap Can but the can is way too tall. I can slide it down in the clamp but I still need 3-1/2" to get battery to clear hood.

I want it to look factory so I dont want to mess around with relocating the can unless it says to do that.

Anybody got a pic of the 2nd battery tray on a 95 HOE installed?

 

[ravingmadman]

+1. My evap can is in the middle of everything. Boo. Pics?

 

[loulblades]

Can you post the page from the service manual that shows how to mount the driver's side tray? I bought it from the dealer and looked at his pic on the computer. It is supposed to go OVER the Evap Can but the can is way too tall. I can slide it down in the clamp but I still need 3-1/2" to get battery to clear hood.

I want it to look factory so I dont want to mess around with relocating the can unless it says to do that.

Anybody got a pic of the 2nd battery tray on a 95 HOE installed?

My service manual is for a 96. The extra battery mounts on the driver's side where a storage box had been.

Looking at the Wrangler Power Products website shows the 95 on the driver's side also.

I notice that on my 04 the aux battery mounts on the passenger side.

 

[Goebz]

Wrangler sent me their inst sheet. No pics but it states that the can must be removed from the original mounting and that it mounts TO the battery tray. That should solve it. If the vcan comes out the tray can go into the captured nuts in the fender and radiator bar. I just gotta get the can mounted to the tray.

Should be on it tomorrow while a budby chases wires on my front diff 4wd actuator. Have new actuator installed and transfer case is working, just actuator not kicking front diff in. I didnt know about the tech update to the new elect motor actuator and replaced the thermal one. He is going to chase wires with a test light to see if there is power.

Will post pics if I can figure that out.

What is the best Dual wiring system? Painless with relay or Wrangler with isolator? I have an isolator I can rig up but I read that they allow .4 - .6 v loss. Relay is way to go just physically wears out sooner.

 

[loulblades]

Relay doesn't drop voltage like the diode isolator. I have read on one of the high powered stereo sites that the voltage spikes you can get on relay closure could possibly cause havoc with amplifiers and other sensitive electronics.

Again here is the relay I used that senses the alternator output to close the relay. You can also set it up to close manually.


http://www.powerwerx.com/emergency-vehicle/battery-integrator.html

BTW the brown wire at actuator should have power when the key is on and the black/white wire should have power when 4WD engaged.

 

[99Yuk]

I ended up buying a 150amp relay. It was on sale...
http://www.princessauto.com/hydraulics/components/electrical/8262800-12-vdc-relay

Now I just need to buy the connecting wires... And free time..

 

[loulblades]

So I guess you are using a switch to isolate the batteries when the truck is not running so you can run accesseries when not discharge the starter battery.

You could make a voltage sensing circuit that would close the relay once the alternator output reaches > 13 volts.

 

[99Yuk]

Actually I wasn't going to go that fancy.

Accessories are going to be wired full time the second batt.
Then I was thinking of using the IGN to turn on the relay for charging the second batt.

I think the IGN is good because as you turn the key, the STARTER would have access to both batts for starting(good in winter). And of course when driving the ALT would charge both batts.

And when the key is off, the relay isolates the first batt and the second batt would be used to power the toys.

That's the plan.

BTW, I'm not sure the proper way to wire this up, but again my plan was to leave everything with the ALT and STARTER stock, and move the power leads of the toys from the first batt to the second batt. Add a new ground wire from the second batt to the chassis. And finally add a wire from the pos on the first batt through the relay to the pos on the second batt. That would make both batts parrallel to each other isolated/joined with the relay.

Being as it's my first duall Batt setup, I'm not sure if I'm missing anything in the plan or not?

 

[loulblades]

If turning on the key to use accessories and that also turns on the relay it kind of defeats the purpose of having the batteries isolated. I think the idea of having an isolated battery setup is so the accessories can be used without running down the main battery.

As far as wiring, my 96 had 2 wires on the + terminal of the battery, one goes to the starter and alternator the other to the fuse/breaker box. I cut the end off the wire that goes to the box and connected it to one side of the relay. I made a jumper to go from the + terminal of the main battery to the other side of the relay (actually just bought a battery cable). Then used a cable from the fuse box terminal to the new battery. Of course then added a ground cable for the new battery.

Also keep in mind if you would run the second battery down real low, you can't start the truck witout getting some juice from the main battery so having the switch to turn on the relay in that situation is beneficial. That's why I have the switch and the voltage sensing setup.