Dual batteries in F-250? - Pirate4x4.Com : 4x4 and Off-Road Forum

kajeepxj · 11-10-2004, 12:47 PM

I recently came across a random, rather large battery from a buddy. It is brand new and he nabbed it from his dealership. I really have no need to run a dual setup in the jeep, so I was thinking about doing it in the tow rig. What all needs to be done? I was thinkin about a battery box in the truck box to keep it in.

Mechanos · 11-10-2004, 12:59 PM

If you're planning on using it for a dual setup in parallel, then both batteries need to be the same size and age for keep them happy. Now if you're talking about running dual isolated batteries, then that's ok.

kajeepxj · 11-10-2004, 01:11 PM

Alright thats good info. I really was just planning on running another battery to power whatever things I might need to power when camping during the winter. AKA an electric heater persay, or some other things of that nature. Woudl it be better to run isolated or in parallel?

mondtster · 11-10-2004, 01:53 PM

I would run it isolated. That way you won't kill the battery in the truck when you are using the other battery for lights and that sort of stuff. The battery isolators aren't terribly expensive either...

That is exactly how I am planning on doing it in my truck. That way I won't kill the truck's battery when I'm using my power inverter.

Mechanos · 11-10-2004, 03:13 PM

Definately run it isolated.

TNScrambler · 11-10-2004, 06:41 PM

As stated, if they are different sizes then yes run it isolated....however if you are wanting to convert to dual batteries and run them parralell, then you could get factory battery trays etc... from a powerstroke truck '94.5 through '97 assuming that you have a truck that body style.

Justin

kajeepxj · 11-11-2004, 08:59 AM

Yeah I have a 96, so those battery trays might work. However, the only thing I am foggy on is how I would keep it charged if it is isolated. I have a friend that knows how to do it but I'm bored at work and wouldn't mind learning what the deal is.

mondtster · 11-11-2004, 09:11 AM

With a battery isolator, you have 2 outputs with one going to each battery, and one input coming from the alternator. There are usually diodes in the isolator so that the power from one battery won't cross over to the other battery, but will allow the power from the alternator to be directed to both batteries.

Think of it in terms of plumbing. There are 2 check valves that won't allow water to back feed, but will allow water to go in both places, if that makes sense...

Maybe someone else will have a better explanation for you if you don't understand this one...

kajeepxj · 11-11-2004, 09:19 AM

I gotcha. So where is the isolator? At the alternator? If I had a battery box in the truck box, would I be running battery cables (2 ga. or so) all the way to that battery? If I had an inverter to run things such as a portable heater or whatever, do you just use a switch to determine which battery you are drawing power from?

mondtster · 11-11-2004, 01:09 PM

http://www.jcwhitney.com/autoparts/C...&searchbtn.y=9

That is a link to a battery isolator that you can get. I'm not sure of the quality of that one though, since I don't know what brand it is.

Basically, you put the battery isolator on the wire coming out of the alternator, and then you run a cable from each battery so that they both charge when the truck is running, but the batteries are still separated. If you are planning on having the battery in the bed of the truck, you will need to run a wire back there from the isolator so that the battery will charge, but otherwise all the other things that you plan to run off the second battery can go straight to it.

No switch is necessary to determine which battery is used with your inverter or heater, because the isolator does that too. Your original battery will only function to start and run the truck, while the second battery will only run your accessories. That is one of the best parts of the isolator, because you won't be able to kill your truck's battery and leave you stranded.

11-10-2004, 12:47 PM	#1 (permalink)
kajeepxj Registered User Join Date: Jun 2002 Member # 12374 Location: Atlanta, Ga Posts: 321	Dual batteries in F-250? I recently came across a random, rather large battery from a buddy. It is brand new and he nabbed it from his dealership. I really have no need to run a dual setup in the jeep, so I was thinking about doing it in the tow rig. What all needs to be done? I was thinkin about a battery box in the truck box to keep it in.

11-10-2004, 12:59 PM	#2 (permalink)
Mechanos Pirate4x4 Addict! Join Date: Aug 2001 Member # 6704 Location: Roosterville, Missouri Posts: 6,986	If you're planning on using it for a dual setup in parallel, then both batteries need to be the same size and age for keep them happy. Now if you're talking about running dual isolated batteries, then that's ok. __________________ It's IHeavy aka TORC KC0UIC -.- -.-. ----- ..- .. -.-. Nothing is foolproof to a sufficiently talented fool.

11-10-2004, 03:13 PM	#5 (permalink)
Mechanos Pirate4x4 Addict! Join Date: Aug 2001 Member # 6704 Location: Roosterville, Missouri Posts: 6,986	Definately run it isolated. __________________ It's IHeavy aka TORC KC0UIC -.- -.-. ----- ..- .. -.-. Nothing is foolproof to a sufficiently talented fool.

11-10-2004, 06:41 PM	#6 (permalink)
TNScrambler Registered User Join Date: Mar 2002 Member # 10818 Location: Knoxville, TN Posts: 842	As stated, if they are different sizes then yes run it isolated....however if you are wanting to convert to dual batteries and run them parralell, then you could get factory battery trays etc... from a powerstroke truck '94.5 through '97 assuming that you have a truck that body style. Justin __________________ random parts stashed in various locations that might someday become part of a Jeep ;)

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11-10-2004, 01:11 PM	#3 (permalink)
kajeepxj Registered User Join Date: Jun 2002 Member # 12374 Location: Atlanta, Ga Posts: 321	Alright thats good info. I really was just planning on running another battery to power whatever things I might need to power when camping during the winter. AKA an electric heater persay, or some other things of that nature. Woudl it be better to run isolated or in parallel?

11-10-2004, 01:53 PM	#4 (permalink)
mondtster Registered User Join Date: Dec 2003 Member # 25349 Location: Waterloo, IA Posts: 3,648	I would run it isolated. That way you won't kill the battery in the truck when you are using the other battery for lights and that sort of stuff. The battery isolators aren't terribly expensive either... That is exactly how I am planning on doing it in my truck. That way I won't kill the truck's battery when I'm using my power inverter.

11-11-2004, 08:59 AM	#7 (permalink)
kajeepxj Registered User Join Date: Jun 2002 Member # 12374 Location: Atlanta, Ga Posts: 321	Yeah I have a 96, so those battery trays might work. However, the only thing I am foggy on is how I would keep it charged if it is isolated. I have a friend that knows how to do it but I'm bored at work and wouldn't mind learning what the deal is.

11-11-2004, 09:11 AM	#8 (permalink)
mondtster Registered User Join Date: Dec 2003 Member # 25349 Location: Waterloo, IA Posts: 3,648	With a battery isolator, you have 2 outputs with one going to each battery, and one input coming from the alternator. There are usually diodes in the isolator so that the power from one battery won't cross over to the other battery, but will allow the power from the alternator to be directed to both batteries. Think of it in terms of plumbing. There are 2 check valves that won't allow water to back feed, but will allow water to go in both places, if that makes sense... Maybe someone else will have a better explanation for you if you don't understand this one...

11-11-2004, 09:19 AM	#9 (permalink)
kajeepxj Registered User Join Date: Jun 2002 Member # 12374 Location: Atlanta, Ga Posts: 321	I gotcha. So where is the isolator? At the alternator? If I had a battery box in the truck box, would I be running battery cables (2 ga. or so) all the way to that battery? If I had an inverter to run things such as a portable heater or whatever, do you just use a switch to determine which battery you are drawing power from?

11-11-2004, 01:09 PM	#10 (permalink)
mondtster Registered User Join Date: Dec 2003 Member # 25349 Location: Waterloo, IA Posts: 3,648	http://www.jcwhitney.com/autoparts/C...&searchbtn.y=9 That is a link to a battery isolator that you can get. I'm not sure of the quality of that one though, since I don't know what brand it is. Basically, you put the battery isolator on the wire coming out of the alternator, and then you run a cable from each battery so that they both charge when the truck is running, but the batteries are still separated. If you are planning on having the battery in the bed of the truck, you will need to run a wire back there from the isolator so that the battery will charge, but otherwise all the other things that you plan to run off the second battery can go straight to it. No switch is necessary to determine which battery is used with your inverter or heater, because the isolator does that too. Your original battery will only function to start and run the truck, while the second battery will only run your accessories. That is one of the best parts of the isolator, because you won't be able to kill your truck's battery and leave you stranded.