Does anyone know what the factory amperage draw is?

[iamduck82]

Does anyone know what the factory load on the charging system is while a TJ is running? I'm running a 136 alternator and am planning my accessories.... lights, winch, compressor, aux power for fridge.

I know all these things aren't running at the same time but was wondering what "extra" juice is pushed to the battery during normal operation.

 

[dbbd1]

That alternator should work fine for you, just make sure your battery is in good condition too.

Once, you start getting up to ridiculous light wattage output, then think about a larger alternator (and battery).

 

[iamduck82]

Thats what i'm getting at. I'm wondering what the "free" amperage is so i can plan accordingly for what i have right now.

if running and rolling down the road requires 65A i know i have 60A worth of auxillary with 11A left to charge. i dont plan on going crazy with accessories but i'd like to know my limits.

Compressor: 30A
Fridge/Cooler: 6-10A
Lights: 10-30A

 

[pagrey]

Thats what i'm getting at. I'm wondering what the "free" amperage is so i can plan accordingly for what i have right now.

if running and rolling down the road requires 65A i know i have 60A worth of auxillary with 11A left to charge. i dont plan on going crazy with accessories but i'd like to know my limits.

Compressor: 30A
Fridge/Cooler: 6-10A
Lights: 10-30A

At idle alternators don't put out anywhere near their peak current. Even an alternator rated at 160A might not give more than a few amps additional current at idle when compared to stock. Once your battery is charged the stock setup can probably dump 100A over what the Jeep needs and a high dollar one might be 140A but that's with the engine running 2k. At idle they will both behave pretty similar. The system doesn't have a simple overhead like you are describing especially at idle.

 

[iamduck82]

Folks,

Under normal use conditions what is the amperage requirement to support the jeeps electrical system?

i know an alternator at idle doesn't produce its advertised current.


The situation i described was not at idle. it was rolling down the road. This "situation" is also a mute point because i'm asking if anyone knows what the factory amperage draw is on a jeep under normal use conditions.

i'm looking for a baseline.

thanks guys.

 

[Mr. Bills]

The situation i described was not at idle. it was rolling down the road. This "situation" is also a mute point because i'm asking if anyone knows what the factory amperage draw is on a jeep under normal use conditions. . . .

If its a mute point don't expect a response.

Come to think of it, if its a moot point you probably won't get a response either.

 

[iamduck82]

If its a mute point don't expect a response.

Come to think of it, if its a moot point you probably won't get a response either.

lol... ok....

i'm just looking for what the standard draw on a jeeps charging system is. idling at the 7-Eleven or cruising down route 66. there is a base line draw on the system.

 

[Mr. Bills]

I don't claim to know anything about auto electrics or diagnostic equipment but it seems to me that you should be able to measure the alternator output of your particular jeep under various conditions. Some scanners and the Torque app come to mind.

I would think that a 136 amp alternator would be plenty for your purposes.

 

[toximus]

I don't claim to know anything about auto electrics or diagnostic equipment but it seems to me that you should be able to measure the alternator output of your particular jeep under various conditions. Some scanners and the Torque app come to mind.

I would think that a 136 amp alternator would be plenty for your purposes.

The regulator is built into the alt. There is no on board monitor for amp draw.

 

[Mr. Bills]

The literature for Torque Pro claims that it can read alternator output in certain situations. That's all I know. I don't own the Torque app but remembered reading that claim when I was searching for a scanner/app that could read transmission temperatures for a non-jeep vehicle I own. As I said, I don't claim to know anything about auto electrics and diagnostics.

What about voltmeters and ammeters? Surely, someone can explain to OP how to best test to determine the "load on the charging system" while his particular TJ is running, which will be more useful to him than a theoretical number or a figure from the FSM.

 

[pagrey]

What about voltmeters and ammeters? Surely, someone can explain to OP how to best test to determine the "load on the charging system" while his particular TJ is running, which will be more useful to him than a theoretical number or a figure from the FSM.

Any clamp type ammeter will give you the answer. The alternator charging cable or battery cable could be used. If you have some basic math skills and a voltmeter you can measure the resistance of the alternator cable and the corresponding voltage drop to get the answer. As you said, the point is moot.

 

[pagrey]

The regulator is built into the alt. There is no on board monitor for amp draw.

Oh really?

 

[TurboTJ]

Any clamp type ammeter will give you the answer. The alternator charging cable or battery cable could be used. If you have some basic math skills and a voltmeter you can measure the resistance of the alternator cable and the corresponding voltage drop to get the answer. As you said, the point is moot.

Good luck trying to measure the resistance of the cable with an Ohmmeter. It will be a small fraction of an Ohm which is below the resolution or accuracy of an Ohmmeter. On the other hand, if you measure the current with a clamp-on ammeter, and the voltage drop with a voltmeter (typically good down to millivolts) you can calculate the resistance.

 

[SSTJ]

Well, I’m just bumping this thread to find out if the OP ever found an answer. I’ve been wondering the same thing, so I was glad to find this post.

I guess another way of asking it is just to list all stock/factory electrical components that operate when the Jeep is running. Adding up their wattage/amperage would give the answer.

@iamduck82