Just wondering what everyone thinks is the point to where a dual battery system is necessary?

I've got 6 rock lights (going to convert to LED soon), a cb radio, two KC 100 watt KC slimlites, and two 12" subwoofers with a 1000 watt amplifier running on one optima red top battery...

I've got five 130 watt KC slimlites waiting to be set up for my roof rack. Is this too much for one battery? Would it still be too much if I unplugged the subs and amplifier?

Thanks, Mark

 

[SUB][/SUB]Depends. An easy way to test is by turning on your jeep, disconnecting the battery, and then turning everything on one by one(this includes your A/C). That will tell you whether your even over the threshold of what your alternator can supply. If your jeep dies, the load was too much. If not, it will stay on and your battery won't even matter.

Beyond that, if you are looking to have a winch, I would strongly advise you to bite the bullet, and look into getting a dual battery setup. A winch will really push your battery, and there is no reason to not have a spare at that point.

 

the answer is none as long as your using LED. standard incondesent(yeah not in my mental spell checck) lights and you top out fast!

 

agree to the led vs incandescent bulbs (although ive got 4 on mine now) but as far as the sound system goes you can add a capacitor to that system to take some strain off the battery

 

DO NOT TO THIS!!! No offense to the poster, but modern vehicles ARE NOT designed to have teh battery disconnected while in operation! This was ok years ago, and the tried and true way to test if the alternator was working at all, but do not do this to a modern vehicle controlled by a computer. If the Jeep dies, it may not even be due to alternator overload, it may be the computer. It is the internet, and I am just another dude with a username and keyboard, so dont take my word for it, talk to a reputable mechanic or even better, the dealership before doing anything like this. Likely, either can connect it to even a laptop with the correct softwware and answer your question. Again, no offense to the person who posted this, but DO NOT do this!!

 

I would have to second this, my mustang and Honda civic would
Not run without a battery when the alternator was good. New cars need the battery for other purposes I guess besides just starting.
Have no idea why, it might just be there to complete the circuit after it has done its starting job.

 

All caps? Seriously man?

Anyway, all I can say, is you want answers for mechanical problems, sure, go to a mechanic, or mechanical engineer. They can be very knowledgeable. And they, by design *dabble* in electronics/electrical work. Want answers for electrical/electronic questions? Go to an electrical/electronics engineer. I'm sure this thread itself has one creeping about in here ;P And, no offense was taken. But really, calm down

Would not run? As in you couldn't drive them, or it wouldn't even stay on after the disconnect? Driving would be a definite no-no, for what I hope are obvious reasons. Staying on, at idle, shouldn't be an issue however, unless the factory installed what they love to call "features". Such a feature could be useful, I suppose, but for some of us... It's about as useful as ESP on a JK. ;P


OP:
When it comes to your problem: When it comes to electrical issues, especially with loads, the only way to really know is to put the system to the test. Electronics and electrically systems all work on "theory", and that must be kept in mind at all times. Just because the math looks right, and everything *should* work, does not mean it will. Especially when you take into account that the people who build systems usually put into place an integrated system of amplifiers/attenuators to keep the system in check. Which, by the way, is usually, lol, around +/- 15%. Now, while 15% itself isn't much.. Try to envision what would happen if every component on just one card, or sub-circuit, was to gravitate up to the +15%, and the rest towards the -15%. Suddenly, your system isn't gonna work. This, of course, is mainly a simplified answer.

When it comes to solutions:

So how do we go about testing your Jeep to see if you need a second battery? Well, as I said, the **easiest** way to do this is to do as I said before. Disconnect the battery. It is the most crude, but it is very easy. And the great part about this is automotive systems are *designed* for sudden power losses. Otherwise changing a car's battery would be a dealership-level event. There are extremely ridiculous examples I can make, but I don't see the need. I'm hoping my point has been made. ***Please Note*** That as this is the simplest way to test, this is also the most error prone. Will it damage your vehicle? Absolutely not. Can it be inaccurate enough that you might find yourself in a situation where you are out in the middle of nowhere with a dead single battery system that was running all of your accessories? Absolutely. This method is "Step 1 Troubleshooting"...Treat it as such.

Another method would be to use a multimeter to read the system, at full load, at the battery. Then, turn off everything. Test again. The "at full load" reading should be higher than the battery when the vehicle is off. This is due to the fact that when the vehicle is on, the alternator is adding itself into the system in parallel with the battery. This is what allows it to not fry the entire system, and also charge the battery with the "excess power" it makes. This would happen to be my favorite. However, it requires a good multimeter.

Another method you could utilize is to build yourself a test bench that mimics your Jeep's electrical footprint. This is insane, and I do not recommend it. Once again, tolerances can make this pointless.

There of course, are quite literally an impossibly large number of ways to test your system to see if your running within envelope. The above are just the ones that I believe were worth, and easiest to mention.

 

[QUOTE=SoCalGSXR;3095755] Well, as I said, the **easiest** way to do this is to do as I said before. Disconnect the battery. QUOTE]

The other guys are RIGHT!!! If you don't believe us, go out and try it for yourself. The Jeep will not opperate with the battery disconnected. PERIOD!

To the OP. The BEST way to find the full load capabilities is to use your brain. Compare the full load calculations of your new equipment to the full load cababilities of your electrical system. Don't forget to count the load of the opperational Jeep itself. This goal can be accomplished with math alone.

The full load capabilities = the alternating Amp rateing + the Amp/hr Rateing of the battery.
The actual load = 60 Amps for the operational Jeep + total load of new accessories.

 

I'd say if you have this much lightning, you'd need at least 2 batteries...



Seriously though, it seems like your current set-up going to LEDs should be ok though unless you run the stereo and lights at once, then a second one would be more of a recommendation.

 

Honestly, I think you'll be fine so long as you aren't running EVERYTHING at once. I can't even fathom a situation where you would need ALL of these operational at the same time. If you need your rock lights on for a spotter, you wouldn't be using the Slimlites(cause you'd blind them). You probably shouldn't be cranking the music either if you need to listen to a spotter's instructions. Just my 0.02.