Go Back   Ford Truck Enthusiasts Forums > Super Duty/Heavy Duty > Super Duty & Heavy Duty
Sign in using an external account
Register Forgot Password?


Super Duty & Heavy Duty 1999 to current Ford F250, F350, F450 and F550 Super Duty with diesel V8 and gas V8 and V10 engines SPONSORED BY:

Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!





 
Reply
 
LinkBack Thread Tools Search this Thread
  #1 (permalink)  
Old 12-05-2011, 04:20 PM
rjfetz1 rjfetz1 is offline
Elder User
 
Join Date: Apr 2006
Posts: 794
rjfetz1 is gaining momentum as a positive member of FTE.rjfetz1 is gaining momentum as a positive member of FTE.
Adding a second battery

I've done some research and decided to go with an isolator and second battery. The second battery is mainly for the plow as it draws so much juice it isn't funny. I am mounting the battery on the frame rail on the passengers side in a plastic battery box. I will run 1 gauge to the isolator & 1 gauge to a ground on the motor.

2 questions - What's the general opinion of doing this? good? bad idea?
Does any one know the exact size of my alternator? I can get a 120 or 160amp isolator and would prefer the smaller size for mounting purposes. I have an 08 5.4.
Thank you for your input.
__________________
2008 F250 S/C 5.4
Reply With Quote
  #2 (permalink)  
Old 12-06-2011, 12:08 AM
Kajtek1's Avatar
Kajtek1 Kajtek1 is offline
Postmaster
 
Join Date: Apr 2006
Location: CA Bay Area
Posts: 3,524
Kajtek1 has a very good reputation on FTE.Kajtek1 has a very good reputation on FTE.Kajtek1 has a very good reputation on FTE.
I had several bad experiences with insulators on my motorhomes. Not only they drop the voltage, but couple of them had leaks and drained batteries.
Way better is battery combiner, or in your case simple relay activated by ignition should work. Those 200 amp continuous duty relays are hard to buy, but last time I combined several 70 amp relays that sold very cheap on ebay.
Reply With Quote
  #3 (permalink)  
Old 12-06-2011, 07:58 AM
Krewat's Avatar
Krewat Krewat is offline
Super Moderator
 
Join Date: Jul 2002
Location: Long Island USA
Posts: 34,299
Krewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputation
Get an isolator that's rated at least twice the max amperage of your alternator. That way it's not stressed too much, the voltage drop won't be as bad.

Overheating the thing will cause it to short out the rectifier. So mount it somewhere it can get air flow, the engine compartment might NOT be the best thing for it especially when you're plowing.

A starter solenoid makes a good high-amperage switch if you don't go with an isolator.
__________________
- art k. - Moderator for the Superduty, V10, 6.2L and FE forums
'13 Taurus SHO 3.5L Ecoboost w/Perf Pkg
'01 F250SD SC SB XLT V10 4x4 Volant CAI Hedman headers 5-star custom tunes on SCT X3
'97 Cougar XR7 30th Anniv Edition 4.6L
'74 F250 Highboy FE390 deceased!
I've been wrong before, I'll be wrong again. Just wait and see. ®
Reply With Quote
  #4 (permalink)  
Old 12-06-2011, 11:07 AM
nitrogen's Avatar
nitrogen nitrogen is offline
Posting Guru
 
Join Date: Dec 2007
Location: Carstairs Alberta
Posts: 1,376
nitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to behold
the only time you need an isolator is if you are planning to operate your electrical load extensively while the engine is not running. now unless you have figured out a way to plow snow without the engine running, that really should not be an issue for you. Save the money and aggravation and just hook the second battery up direct
__________________
2005 F350 Lariat crew 4x4
traded F350 XLT supercab 4x4 what a stinker
Reply With Quote
  #5 (permalink)  
Old 12-06-2011, 01:45 PM
rjfetz1 rjfetz1 is offline
Elder User
 
Join Date: Apr 2006
Posts: 794
rjfetz1 is gaining momentum as a positive member of FTE.rjfetz1 is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by nitrogen View Post
the only time you need an isolator is if you are planning to operate your electrical load extensively while the engine is not running. now unless you have figured out a way to plow snow without the engine running, that really should not be an issue for you. Save the money and aggravation and just hook the second battery up direct
I would love to do it that way...but I heard my starter is not "wound" for dual batteries and therefore will be short lived. I am trying to find more info on my starter.
__________________
2008 F250 S/C 5.4
Reply With Quote
  #6 (permalink)  
Old 12-06-2011, 02:38 PM
mwsF250 mwsF250 is offline
Postmaster
 
Join Date: Jun 2008
Location: Wayyy NoCal, USA
Posts: 2,564
mwsF250 has a great reputation on FTE.mwsF250 has a great reputation on FTE.mwsF250 has a great reputation on FTE.mwsF250 has a great reputation on FTE.mwsF250 has a great reputation on FTE.
Quote:
Originally Posted by rjfetz1 View Post
I would love to do it that way...but I heard my starter is not "wound" for dual batteries and therefore will be short lived. I am trying to find more info on my starter.
Good luck trying to find anything. You won't. You were given some seriously clueless mis-information. Unless the giver was assuming you were going to wire the two batteries in series? But that doesn't make sense either as the starter frying would be the least of your worries if you dumped 24+ volts into the system.

The starter wouldn't care if you had 1 or 200 batteries. It's going to draw as much current as it needs from whatever source you give it.
__________________
'99 F250 V10 Super Cab Long Bed 4x4. '06 short block, PI conversion, modded airbox, 5 Star custom tune, FM50BB, 315/75-16 GY Duratracs, mild lift, 4.30 LSD, Ride-Rite bags, on board air, Rancho RS9000 w/MyRide, under bed subwoofer, 160 amp Quick Start large case alternator
Why, yes, I am some kind of geek engineer. Thank you for asking.
Reply With Quote
  #7 (permalink)  
Old 12-06-2011, 03:00 PM
Kajtek1's Avatar
Kajtek1 Kajtek1 is offline
Postmaster
 
Join Date: Apr 2006
Location: CA Bay Area
Posts: 3,524
Kajtek1 has a very good reputation on FTE.Kajtek1 has a very good reputation on FTE.Kajtek1 has a very good reputation on FTE.
There is big difference between dual batteries and dual battery banks.
Having dual batteries is common on diesels and with basic know-how it is no big deal.
Dual battery banks are used when second bank is being discharged with engine off and you want preserve starting power in the first bank.
That applies to motorhomes and Police cruisers that use lot of lights with engines off.
I am not familiar with snow plow, but as nitrogen indicate, not likely you really need it.
Reply With Quote
  #8 (permalink)  
Old 12-06-2011, 03:04 PM
Sebs Sebs is offline
Senior User
 
Join Date: Oct 2007
Posts: 122
Sebs is starting off with a positive reputation.
I haven't heard that one before! Just hook them together in parallel - positive to positive and ground the negative. Nothing bad will happen.
Reply With Quote
  #9 (permalink)  
Old 12-06-2011, 03:53 PM
rjfetz1 rjfetz1 is offline
Elder User
 
Join Date: Apr 2006
Posts: 794
rjfetz1 is gaining momentum as a positive member of FTE.rjfetz1 is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by Sebs View Post
I haven't heard that one before! Just hook them together in parallel - positive to positive and ground the negative. Nothing bad will happen.
This is what i was thinking about just doing.

Some research I found on the isolator says it would "charge" both batteries equally and seperate accessories (my case plow) from the truck battery?

My whole reason for doing this is to prevent the lights/defroster from dimming everytime I use the plow. I can't believe it is good for the truck to draw so much current over & over & over and having motors and lights dimming.
__________________
2008 F250 S/C 5.4
Reply With Quote
  #10 (permalink)  
Old 12-06-2011, 04:07 PM
Sebs Sebs is offline
Senior User
 
Join Date: Oct 2007
Posts: 122
Sebs is starting off with a positive reputation.
Quote:
Originally Posted by rjfetz1 View Post
Some research I found on the isolator says it would "charge" both batteries equally and seperate accessories (my case plow) from the truck battery?
As Nitrogen said, isolators are typically used for running things from a second battery when the engine is off. You can run that battery down and still start your engine with the other battery. When the engine is running both batteries are connected together and the plow would be pulling current from both anyway. So I see no need for an isolator or relay. The lights are dimming because the plow is pulling a huge current load from the battery. With two batteries in parallel, you have twice the capacity to pull current from so the battery voltage shouldn't dip as much and you'll see less light dimming. It may not go completely away but should be improved. Make sure the plow is connected as close to the battery post as possible - preferably at the post.
Reply With Quote
  #11 (permalink)  
Old 12-06-2011, 08:37 PM
nitrogen's Avatar
nitrogen nitrogen is offline
Posting Guru
 
Join Date: Dec 2007
Location: Carstairs Alberta
Posts: 1,376
nitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to beholdnitrogen is a splendid one to behold
yup sebs and mw are dead on. pos to pos =2x the amperage available, same volts. even perfect connections have a voltage drop, so the more connections between the battery and the alternator the lower your voltage at the battery. wiring in an isolator just adds another level of connections. they will charge better and more equally without an isolator in my opinion.
__________________
2005 F350 Lariat crew 4x4
traded F350 XLT supercab 4x4 what a stinker
Reply With Quote
  #12 (permalink)  
Old 12-07-2011, 05:14 AM
rjfetz1 rjfetz1 is offline
Elder User
 
Join Date: Apr 2006
Posts: 794
rjfetz1 is gaining momentum as a positive member of FTE.rjfetz1 is gaining momentum as a positive member of FTE.
OK, 2 batteries, no isolator it is then! Thank you all very much for your input.
__________________
2008 F250 S/C 5.4
Reply With Quote
  #13 (permalink)  
Old 12-07-2011, 09:02 AM
aaronbrace aaronbrace is offline
Senior User
 
Join Date: Feb 2005
Location: Hudson, NH
Posts: 160
aaronbrace is starting off with a positive reputation.
For what it is worth I agree with the above. I am not familiar with 'isolators' used in vehicles but my assumption would be that they are nothing more than a big diode (or bank of diodes). As soon as you throw a diode in you are going to lose .7Volts from the natural forward voltage drop of a diode.

I would also strongly suggest you ensure that both batteries, the existing and the new, are of a similar age. If the existing one is more than 1-2 years old I would replace it at the same time. Otherwise the newer battery will be pulled down to the older one and spend a bunch of its time trying to charge it.

This is a common problems for battery banks on big UPS systems and Solar systems so I thought I would mention it.

---Aaron
Reply With Quote
  #14 (permalink)  
Old 12-07-2011, 10:01 AM
TRENT310's Avatar
TRENT310 TRENT310 is offline
Posting Guru
 
Join Date: Jan 2010
Location: Whitecourt AB, Canada
Posts: 1,493
TRENT310 has a brilliant futureTRENT310 has a brilliant futureTRENT310 has a brilliant futureTRENT310 has a brilliant futureTRENT310 has a brilliant futureTRENT310 has a brilliant futureTRENT310 has a brilliant futureTRENT310 has a brilliant futureTRENT310 has a brilliant futureTRENT310 has a brilliant futureTRENT310 has a brilliant future
TRENT310
Quote:
Originally Posted by aaronbrace View Post
This is a common problems for battery banks on big UPS systems and Solar systems so I thought I would mention it.
Even more important on 48-52V systems because most of those banks are made out of 2V single cells and in a big series string instead of multi-cell batteries in parallel... one open or shorted cell messes everything else up.
__________________
2011 F-350SD - SRW XLT FX4 CCLB: 6.7L PSD, 6R140, 3.55:1 EL, Job 2 (Daily Driver)
With BDS 6" 4-Link & Rear Leafs, Fox 2.0 IFP, Toyo MT 38x13.50R18 on 18x9 Fuel D525, Bulletproof Prerunner Bumper, EGR/DPF/SCR delete.

1994 RAM 2500 - SLT Laramie 4x4 RCLB 5.9L 6BT NV4500 (Project)
2009 Tundra - SR5 4x2 RCLB 5.7L 4.30:1 (Sold)
Others: 1995 F-350HD DRW 4x2 CCFB 7.3L-T444E PSD // 2004 F-350SD SRW 4x4 CCLB 6.0L-VT365 PSD.
Reply With Quote
  #15 (permalink)  
Old 12-07-2011, 10:15 AM
Krewat's Avatar
Krewat Krewat is offline
Super Moderator
 
Join Date: Jul 2002
Location: Long Island USA
Posts: 34,299
Krewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputation
One problem is when you use that plow a lot, you WILL drain both batteries if the alternator isn't big enough to keep up with it.

If you're going to just wire in another battery, get a real voltage gauge and keep an eye on it. You could potentially shut down the truck and not get it started again
__________________
- art k. - Moderator for the Superduty, V10, 6.2L and FE forums
'13 Taurus SHO 3.5L Ecoboost w/Perf Pkg
'01 F250SD SC SB XLT V10 4x4 Volant CAI Hedman headers 5-star custom tunes on SCT X3
'97 Cougar XR7 30th Anniv Edition 4.6L
'74 F250 Highboy FE390 deceased!
I've been wrong before, I'll be wrong again. Just wait and see. ®
Reply With Quote
Old 12-07-2011, 10:15 AM
Reply

Go Back   Ford Truck Enthusiasts Forums > Super Duty/Heavy Duty > Super Duty & Heavy Duty

Tags
2nd, adding, backup, batteries, battery, connect, duty, ford, heavy, install, parallel, plow, plowing, small, truck

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On
Forum Jump



All times are GMT -5. The time now is 10:30 PM.


Powered by vBulletin® Version 3.7.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.5.2 ©2010, Crawlability, Inc.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup