NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Other Technical Forums > Jeep CJs and Wranglers > Wrangler JK and JL (2007 - Present)
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

Wrangler JK and JL (2007 - Present) Technical forum for new-generation Jeep Wrangers.

Reply
 
Thread Tools Rate Thread Display Modes
  #31  
Old July 20th, 2017, 19:07
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 697
Re: upgrading alternator wiring

Quote:
Originally Posted by Green XJ Jeep View Post
If you are going to go that far over the rated output then there is no need for any forn of circuit protection.
That is not that far out. If the alt fails, it will blow the fuse.

Failure is failure.
Reply With Quote
  #32  
Old July 20th, 2017, 19:40
donthelegend donthelegend is offline
NAXJA Member
 
Join Date: Apr 2010
Location: St. Louis, MO
Posts: 388
Re: upgrading alternator wiring

Quote:
Originally Posted by Jeep Driver View Post
There is nothing there that I said that was wrong or incorrect.


He will not be fine with 125 amp breaker.


There is plenty of scenarios in which he will be a full load, or that the alt will sense a full load.

Cruising the back roads at night with AC, aux lights, Efan, head unit with amp......etc.........

Jump starting another vehicle.

Or any thing else that will drain the battery...........like running a wench.

Mine puts out 100amps at idle..........not 5amps here and 30amps there.........100amps.

No, it doesn't. That's not how electronics work. It puts out up to 100 amps at idle. Go throw a clamp on meter on there if you don't believe me but without running a winch, a ton of lights, or a big stereo, that alternator isn't putting out anywhere near 100 amps at idle most of the time. Now start your winch and absolutely the alternator will produce that 100 amps but for normal conditions, it's not making 100 amps.

My comments on a 125 amp breaker/fuse being fine were based on the assumption that he doesn't actually need more than 125 amps out of his alternator... Because most people don't and unless you've upgraded the stock alternator, it's not capable of putting out more than that anyway.

You can certainly argue that an individual needs more than 125 amps, in which case they need a bigger breaker/fuse, but most parts stores reman'd alternators barely make their rated current near max rpm, and at or near idle, where most people tend to run winches or jump start other cars, they're only capable of making a fraction of that, and once again the lower rated fuse is not going to cause a problem.

I'm not saying I recommend putting a 125 amp breaker on a 160 amp alt, but it's not instantly going to trip, and is not going to hurt anything either.
Reply With Quote
  #33  
Old July 21st, 2017, 11:17
Green XJ Jeep Green XJ Jeep is offline
NAXJA Member 4950
 
Join Date: Mar 2011
Location: Spanaway Wa
Posts: 560
Re: upgrading alternator wiring

Some needs to tell power master to put "@ 100% load" on their alternator tags.
Reply With Quote
  #34  
Old July 21st, 2017, 18:01
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 697
Re: upgrading alternator wiring

Quote:
Originally Posted by Green XJ Jeep View Post
Some needs to tell power master to put "@ 100% load" on their alternator tags.
Maybe you need to think a little harder.


Here's some homework for you-

You add up all the devices that are running on the average vehicle. Fuel pump, ignition, PCM, TCU, headlights, aux lights, AC, amp and radio, maybe a CB or other..........maybe a trailer, lights, Ebrakes, trailer battery,..........etc........Efan........wipers... .........whatever.

Add it all up......typical summer evening.......running full tilt.



Bet you'll be over 100 amps..........maybe 125 amps............continuous load.


Your alt is running full load all the time
Reply With Quote
  #35  
Old July 21st, 2017, 21:42
Green XJ Jeep Green XJ Jeep is offline
NAXJA Member 4950
 
Join Date: Mar 2011
Location: Spanaway Wa
Posts: 560
Re: upgrading alternator wiring

Quote:
Originally Posted by Jeep Driver View Post
Maybe you need to think a little harder.


Here's some homework for you-

You add up all the devices that are running on the average vehicle. Fuel pump, ignition, PCM, TCU, headlights, aux lights, AC, amp and radio, maybe a CB or other..........maybe a trailer, lights, Ebrakes, trailer battery,..........etc........Efan........wipers... .........whatever.

Add it all up......typical summer evening.......running full tilt.



Bet you'll be over 100 amps..........maybe 125 amps............continuous load.


Your alt is running full load all the time
At full load or duty cycle yes a person is going to max out their alt. Just like your alternator when it was tested, it was put under full load and the max amps it was capable of delivering at idle was 100.

An alternator is not going to produce max amps all the time.

Maybe you should quit embarrassing yourself and actually read on how charging systems actually work.
Here let me help,
https://www.lifewire.com/understandi...ratings-534785

Here is a vid that kind of shows it. If you look at idle its only putting out 50 amps until a load is applied,
https://www.youtube.com/watch?v=Q3HKivSo_TY

Last edited by Green XJ Jeep; July 21st, 2017 at 21:52.
Reply With Quote
  #36  
Old July 21st, 2017, 21:59
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 697
Re: upgrading alternator wiring

Quote:
Originally Posted by Green XJ Jeep View Post
At full load or duty cycle yes a person is going to max out their alt. Just like your alternator when it was tested, it was put under full load and the max amps it was capable of delivering at idle was 100.

An alternator is not going to produce max amps all the time.

Maybe you should quit embarrassing yourself and actually read on how charging systems actually work.
Here let me help,
https://www.lifewire.com/understandi...ratings-534785

Here is a vid that kind of shows it. If you look at idle its only putting out 50 amps until a load is applied,
https://www.youtube.com/watch?v=Q3HKivSo_TY
Quoting from your own article, again, making MY point.

In this case, your alt is UNDERcharging and yet the alt is at full tilt most of the time.

Any extras on most of our Jeeps and we are drawing 100amps.


Quote:
50/120A 13.5V

Since we know that both ISO and SAE standards call for a format of "IL / IRA VTV" actually pretty easy to interpret this rating.

First, we’ll look at IL, which, in this case, is 50. That means this alternator is capable of putting out 50A at the “low” test speed, which is either 1,500 RPM or “the idle speed of the engine,” depending on which standard you’re dealing with.

The next number is 120, which is “IR” or the amperage output at the “rated” test speed. In this case, this alternator is capable of putting out 120A @ 6,000 RPM.

Since this is the “rated” test speed, this number is usually used for the alternator’s rated output.

The last number is 13.5V, which is “VT” or the voltage that the alternator was held at during the test. Since an alternator’s output can vary both up and down from 13.5V in real world situations, it’s actual output limits will vary from the idle and rated numbers.


In this case, stop and go traffic...............your alt will never keep up.
Reply With Quote
  #37  
Old July 21st, 2017, 22:06
Green XJ Jeep Green XJ Jeep is offline
NAXJA Member 4950
 
Join Date: Mar 2011
Location: Spanaway Wa
Posts: 560
Re: upgrading alternator wiring

Quote:
Originally Posted by Jeep Driver View Post
Quoting from your own article, again, making MY point.

In this case, your alt is UNDERcharging and yet the alt is at full tilt most of the time.

Any extras on most of our Jeeps and we are drawing 100amps.






In this case, stop and go traffic...............your alt will never keep up.
Your whole argument is, an alternator is going to produce max amps all the time regardless of demands. Which is completely false.
At full load yes, sitting in the driveway warming up or idling in traffic with no auxiliary devices running it most definitely will not.
Reply With Quote
  #38  
Old July 21st, 2017, 22:07
Green XJ Jeep Green XJ Jeep is offline
NAXJA Member 4950
 
Join Date: Mar 2011
Location: Spanaway Wa
Posts: 560
Re: upgrading alternator wiring

You must have completely missed this,
Alternator Output Supply and Demand

With all of that in mind, it’s also important to understand that the output of an alternator is tied to the demands of the electrical system in addition to its inherent capabilities and the speed that its input shaft is rotating at any given moment.
In essence, while maximum alternator output is dependent on the rotational speed of the input shaft, the actual output is load-dependent. That basically means that an alternator will never generate more current than is called for by the momentary demands of the electrical system.
What that means, in the real world, is that while an underpowered alternator can cause problems by not meeting the needs of your electrical system, a substantially overpowered alternator represents a lot of wasted potential. For instance, a high output alternator might be capable of putting out upwards of 300A, but it won’t actually provide more amperage than a stock 80A unit if that’s all the electrical system ever tries to draw.
Reply With Quote
  #39  
Old July 22nd, 2017, 00:04
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 697
Re: upgrading alternator wiring

Quote:
Originally Posted by Green XJ Jeep View Post
Your whole argument is, an alternator is going to produce max amps all the time regardless of demands. Which is completely false.
At full load yes, sitting in the driveway warming up or idling in traffic with no auxiliary devices running it most definitely will not.

No, my whole argument is you dont even know what demand is at any given moment.

The argument began when the other posted stated that the OP would likely be OK with a 125 breaker and a 160 alt.


My argument is that a 160 alt will put out 160, at some point, or, all day long, if demand is there, like jump starting another car/truck.
A failing battery will cause a full load on the alt......whatever, whenever.
Reply With Quote
  #40  
Old July 22nd, 2017, 09:22
techno1154's Avatar
techno1154 techno1154 is offline
NAXJA Member
 
Join Date: Apr 2003
Location: In the islands
Posts: 2,447
Re: upgrading alternator wiring

Quote:
Originally Posted by donthelegend View Post
No, it doesn't. That's not how electronics work. It puts out up to 100 amps at idle. Go throw a clamp on meter on there if you don't believe me but without running a winch, a ton of lights, or a big stereo, that alternator isn't putting out anywhere near 100 amps at idle most of the time. Now start your winch and absolutely the alternator will produce that 100 amps but for normal conditions, it's not making 100 amps.

My comments on a 125 amp breaker/fuse being fine were based on the assumption that he doesn't actually need more than 125 amps out of his alternator... Because most people don't and unless you've upgraded the stock alternator, it's not capable of putting out more than that anyway.

You can certainly argue that an individual needs more than 125 amps, in which case they need a bigger breaker/fuse, but most parts stores reman'd alternators barely make their rated current near max rpm, and at or near idle, where most people tend to run winches or jump start other cars, they're only capable of making a fraction of that, and once again the lower rated fuse is not going to cause a problem.

I'm not saying I recommend putting a 125 amp breaker on a 160 amp alt, but it's not instantly going to trip, and is not going to hurt anything either.
That quote from the alternator manufacturer is only a test on a test bed. It is not an indication of the amount of power the alternator will put out on a regular XJ or any vehicle for that matter that have the minimum load applied to it. Case and point, My XJ came with the standard 90 AMP alternator which was perfectly fine running everything the XJ came with at idle. Then I added dual electric fans that require 50 AMPS and everything went to hell after that. I could make the alternator on my XJ put out all 160 AMPS at 2,000 RPM by jumping the switched ground on the back of the alternator to a permanent ground at which point the voltage would get to 18+. And yes, I have done that in the past when I was having some electrical problems.

I too have added a 160 AMP alternator and if the fans are not running the AMP draw is less than 40. Now if throw in plenty of AMP gobbling equipment in the XJ the AMP draw will increase only these equipment are actually working and even so, the alternator will only deliver the amount of AMPS necessary to operate these equipment properly. For most of us it will be less than 100 AMPS. In my case I added another battery of more than 900 CCA's to help to smooth things out at start up.

There is absolutely nothing wrong with a circuit breaker. They are the preferred electrical protector over a fuse in house AC and for the protection of critical implements that need to be on,...think of marine/boats, airplanes etc.. Keep in mind that breakers do go bad and trip prematurely unlike a fuse. Also, they could be bad right out of the box. The only disadvantage I see for a breaker in the XJ is the amount of space they need to mount them.
__________________
Patrick

#594
1996 XJ; 4.0L; AW4; NP231; SYE; D30 and D44; ECTED; 4.10 gears; 30X9.5 -15 BFG/AT/KO; 3" lift; Rusty's LCA; JKS ADJ UCA; Kevins ADJ Track bar; Drawtite Front Receiver; Dual Electric Fans; Dual Battaries.
Reply With Quote
  #41  
Old July 22nd, 2017, 10:26
donthelegend donthelegend is offline
NAXJA Member
 
Join Date: Apr 2010
Location: St. Louis, MO
Posts: 388
Re: upgrading alternator wiring

Quote:
Originally Posted by Jeep Driver View Post
Maybe you need to think a little harder.


Here's some homework for you-

You add up all the devices that are running on the average vehicle. Fuel pump, ignition, PCM, TCU, headlights, aux lights, AC, amp and radio, maybe a CB or other..........maybe a trailer, lights, Ebrakes, trailer battery,..........etc........Efan........wipers... .........whatever.

Add it all up......typical summer evening.......running full tilt.



Bet you'll be over 100 amps..........maybe 125 amps............continuous load.


Your alt is running full load all the time
I'd gladly take that bet considering the stock XJ alternator is only rated at 90 amps and does just fine for most people even with additional lights, radios etc.

Of course the OP has now stated that he's not working on an XJ so specific loads beyond the XJ platform I can't really comment on... But you're way off base for an XJ.
Reply With Quote
  #42  
Old July 23rd, 2017, 15:38
Green XJ Jeep Green XJ Jeep is offline
NAXJA Member 4950
 
Join Date: Mar 2011
Location: Spanaway Wa
Posts: 560
Re: upgrading alternator wiring

Quote:
Originally Posted by Jeep Driver View Post
Maybe you need to think a little harder.


Here's some homework for you-

You add up all the devices that are running on the average vehicle. Fuel pump, ignition, PCM, TCU, headlights, aux lights, AC, amp and radio, maybe a CB or other..........maybe a trailer, lights, Ebrakes, trailer battery,..........etc........Efan........wipers... .........whatever.

Add it all up......typical summer evening.......running full tilt.



Bet you'll be over 100 amps..........maybe 125 amps............continuous load.


Your alt is running full load all the time
Bet your wrong.
In fact I know you are wrong, mainly because I do have an amp gauge, know how to work it and I can empirically prove you are wrong.

Try again please.
Reply With Quote
  #43  
Old July 23rd, 2017, 18:05
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 697
Re: upgrading alternator wiring

Quote:
Originally Posted by Green XJ Jeep View Post
Bet your wrong.
In fact I know you are wrong, mainly because I do have an amp gauge, know how to work it and I can empirically prove you are wrong.

Try again please.
Alright then, F-ing do it.
Reply With Quote
  #44  
Old July 23rd, 2017, 18:06
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 697
Re: upgrading alternator wiring

Quote:
Originally Posted by donthelegend View Post
I'd gladly take that bet considering the stock XJ alternator is only rated at 90 amps and does just fine for most people even with additional lights, radios etc.

Of course the OP has now stated that he's not working on an XJ so specific loads beyond the XJ platform I can't really comment on... But you're way off base for an XJ.
Again, to you, what are the loads?


Put some numbers down or STFU./
Reply With Quote
  #45  
Old July 23rd, 2017, 18:11
donthelegend donthelegend is offline
NAXJA Member
 
Join Date: Apr 2010
Location: St. Louis, MO
Posts: 388
Re: upgrading alternator wiring

Quote:
Originally Posted by Jeep Driver View Post
Again, to you, what are the loads?


Put some numbers down or STFU./
Clamp on amp gauge is gonna be here tomorrow... May take me a couple days but I'll post the actual numbers when I have them.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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 Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Upgrading the alternator.... Senior_XJ Modified Tech Discussion 3 September 7th, 2008 23:15
Upgrading an alternator? Double Down Modified Tech Discussion 41 March 27th, 2008 18:23
Higher Amp Alternator Upgrading ihscoutlover Modified Tech Discussion 0 January 16th, 2008 19:02
Upgrading Alternator - Which One? Spidey Modified Tech Discussion 6 January 20th, 2005 15:19
Upgrading the Alternator wilson0309 Modified Tech Discussion 18 October 21st, 2003 08:36


All times are GMT -7. The time now is 06:43.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014