Dual batteries help

[Trollhole]

So I'm gonna mount two Optimas underneath my seat. Using an 180amp alt.

What would be the best way to wire them?

I was thinking of using 2/0 welding cables

Since I'm so far away from the engine compartment I need some assurance that if the cable gets hit that I won't let all the smoke out of the wires.

I was thinking on using a circuit breaker at the batteries and then a couple of distribution blocks at the firewall splitting up power to the two fuse panel, winch and the starter.

Biggest distribution block I can find is ones with a 3/8 bolt. Will this be big enough?

When It comes to circuit breakers biggest I can find is 150 amps. Is this going to be enough when using the winch or starter? And is it ok to backfeed through a circuit breaker (alt).

The ALt is 180 amps. Does this cause an issue if I use only a 150 amp alt?

 

[Sharp38]

There are a bunch of ways to wire the two batteries. I have had pretty good luck using two golf cart 100 % duty cycle solenoids. Both solenoids are operated by the key (accessory side of the of the key for one an ignition side of the key for the other). When you turn off the key, both batteries are out of the circuit. When you start, you have one battery starting. When you run, you have both batteries in parallel, getting charged. In accessory, you have the other battery. One battery is hooked to the winch and other accessory circuits. The other is hooked to the starter. If you drain a battery using the winch, you still have the other to start the vehicle. Don Home Page Wolf Creek Rod Works

 

[mrlocksmith]

This is for my '60 but you can get an idea of what fuses I used.

https://forum.ih8mud.com/60-series-wagons/213526-write-up-fj60-dual-battery-install.html

Mark

 

[matt.mcinnes]

So I'm gonna mount two Optimas underneath my seat. Using an 180amp alt.

What would be the best way to wire them?

I was thinking of using 2/0 welding cables

Since I'm so far away from the engine compartment I need some assurance that if the cable gets hit that I won't let all the smoke out of the wires.

I was thinking on using a circuit breaker at the batteries and then a couple of distribution blocks at the firewall splitting up power to the two fuse panel, winch and the starter.

Biggest distribution block I can find is ones with a 3/8 bolt. Will this be big enough?

When It comes to circuit breakers biggest I can find is 150 amps. Is this going to be enough when using the winch or starter? And is it ok to backfeed through a circuit breaker (alt).

The ALt is 180 amps. Does this cause an issue if I use only a 150 amp alt?

Just run the welding cable inside the chassis rail I do with mine. Triple insulated triangular 1000V, very supple cable easy to bend not cheap but the best option by far. Never had an issue with either of mine and you know where my batteries are.


Matt

Edit, My kill switch is rated at 200A for 20sec Load. If your taking longer than 20 sec to start the truck you have issues and your going to kill your starter. I still however don't run the winch through it as there is nothing on the market that can cope with a high mount under full load. The odds however on doing a cable while winching is greatly reduced. Bonus the key is removable.

Try a good Nascar supplier, plenty of cheap kill switches in the Auto shops but comp regs are far stricter and higher quality is demanded.

 

[1973Guppie]

my dual batt's are wired up into a boat switch, which sits in the center tuffy console, from there the positive goes to the starter and the neg goes to the frame, from the starter I have a line going to 2 fuse blocks, one key hot and one always hot.

the boat switch method has worked very well for me. I can choose to use one or the other or both of the batt's.

Noah

 

[Trollhole]

my dual batt's are wired up into a boat switch, which sits in the center tuffy console, from there the positive goes to the starter and the neg goes to the frame, from the starter I have a line going to 2 fuse blocks, one key hot and one always hot.

the boat switch method has worked very well for me. I can choose to use one or the other or both of the batt's.

Noah

Do you have any sort of fuse between the batter and starter?

Am I just being anal? Should I just wire it straight from the batteries and forgo the fuse/circuit breaker to the front?

 

[mtweller]

Marshall, that is NOT ANAL!! My former job was forensic analysis and every vehicle fire we saw was a result of an unprotected conductor. A DC 300A time-delayed fuse is cheap insurance IMHO. You shouldn't be blowing that, and if you do, it may be because it saved your rig or your life.

I don't care how much you insulate wiring, vibrations over time can wreak havoc!

 

[1973Guppie]

Do you have any sort of fuse between the batter and starter?

Am I just being anal? Should I just wire it straight from the batteries and forgo the fuse/circuit breaker to the front?

no, I don't, the boat switch is usually set to OFF when parked, but to your point it would be a good idea for sure, never had any problems, I did make sure that the cables are very well insulated where they go through the floor

 

[Trollhole]

NEW PERFORMANCE TEKNIQUE 300A CIRCUIT BREAKER 300 AMP - eBay (item 350061042779 end time May-26-08 20:12:49 PDT)

Hmmm

 

[Trollhole]

I've ordered the parts to wire it like this minus the alt disconnect.

Alternator Field Disconnect - Resources - Blue Sea Systems

went with 2/0 cable and some distribution blocks. Also using two red top optimas.

 

[WES1977]

how about putting the cables in flexy conduit?

 

[Trollhole]

how about putting the cables in flexy conduit?

Definitely going to do that.

 

[WES1977]

did you move your fuel tank? and installing under the pass seat?

 

[Trollhole]

did you move your fuel tank? and installing under the pass seat?

No fuel tank is in stock location.

I planning on sinking the batteries under my seat and running the cables either on my side of the tranny tunnel up around the back of the heater or under the floorboard up to the back of the motor and then back over. If I run it in flexable conduit and secure it down I shouldn't have an issue.

I did have the idea of running it under one of the floorboard up the drain for the non working cowl vent and putting my distribution blocks in there and seal it up with a piece of plexiglass.

Problem is I'm using 2/0 wire and 2 strands isn't going to fit a 3/4 line.

I'll figure it all out.

Question on grounding. SHould I run a ground all the way to the front? Or just ground to the frame underneath the batteries?

 

[WES1977]

Question on grounding. SHould I run a ground all the way to the front? Or just ground to the frame underneath the batteries?

Frame to the easiest place imho.

 

[dbenke]

Make sure and run a ground to the motor somewhere

 

[Coolerman]

Make sure and run a ground to the motor somewhere

x2!

The alternator needs a good low resistance ground. A large ga jumper from the frame to a starter mounting bolt will do the trick. Or if you are really anal and don't want to scrape the paint off your alternator mounting bracket then also add a ground to the case of the alternator.

 

[Coolerman]

There are a bunch of ways to wire the two batteries. I have had pretty good luck using two golf cart 100 % duty cycle solenoids. Both solenoids are operated by the key (accessory side of the of the key for one an ignition side of the key for the other). When you turn off the key, both batteries are out of the circuit. When you start, you have one battery starting. When you run, you have both batteries in parallel, getting charged. In accessory, you have the other battery. One battery is hooked to the winch and other accessory circuits. The other is hooked to the starter. If you drain a battery using the winch, you still have the other to start the vehicle. Don Home Page Wolf Creek Rod Works

I understand how you are using the Acc and ST positions on the keyswitch to activate the two solenoids, (pretty neat idea BTW)but I don't underestand how you hooked it up to allow charging both batteries while NOT allowing both batteries to power the starter or winch.

This is what you have?
You have Solenoid #1 in line between the starter and Battery #1 and Solenoid #2 between the winch and Battery #2, right?

Then you have the alternator connected to BOTH batteries so it can charge them. Unless you have a means of disconnecting the alternator when starting or winching, current will flow from BOTH batteries through the connecting wire(s) from the alternator to both batteries. Or am I missing something here?

 

[Trollhole]

Well my first snag.

I'm running TBI. If I rotate the switch will I lose programming on the computer?

 

[Coolerman]

Well my first snag.

I'm running TBI. If I rotate the switch will I lose programming on the computer?

Not if you run a small fused wire to the 'computer' directly from one of the batteries BEFORE it goes through the switch.