Let the record reflect that I am an electrical misfit. With that out of the way. I am looking to get an inverter for tailgating purposes. i.e. small TV, blender lap top etc...... attached to battery by alligator clips.

While maintaining the stock battery and not going with a dual setup how long do you think that battery power would last without the engine running. I would like to watch the TV without worrying about not making it home.

I know that there are variables and an exact number cannot possibly be established but a ball park.

 

The time will depend on how much power all the devices are drawing. You know like for example you can run a cell phone charger for a few days and still be able to fire up your vehicle, but if you have the stereo blasting then it only may be a few hours.

You'll probably have to just play it by ear and see how long you can do your thing before the vehicle won't start and just learn from experience.

I would recommend you buy one of those portable jump starters, bring it along with you to your tailgate party and that way you have a back up jump starting source in case your JK doesn't start. They're only like $60. I have one which I leave plugged in and charging in my garage and they come in very handy, for a needed jump start or to inflate my tires, or to just use as a portable power device that I can plug devices into the included cigarette lighter socket.

One thing that you should be aware of is that the stock battery is not a deep cycle battery....so discharging it too far can damage the battery and make it fail completely. So with typical batteries like the stock one, you can normally discharge them up to 50% of their full charge level and be able to fully recharge them....if you allow them to get drained further than that, then you run the risk of damaging the battery so that it will never fully recharge or hold a charge again. A "Marine" battery is called a deep cycle battery because you can drain those up to 80% of their full charge level without damaging them. So you might want to consider buying a marine rated battery if this is something you plan on doing often.

Go get yourself a Sears Diehard "Platinum" Marine battery ($189). This will allow you to run your stuff much longer than the stock battery, and help prevent yourself from damaging the battery in the event that you do deep discharge the battery. Some have reported running these batteries without the vehicle running for well over 6 hours with the stereo blasting, and doing similar things you listed on camping trips, with their Wrangler firing right up after that time. You don't really need a dual battery set up, but you do need to make sure you have the right battery for your intended use....where currently the stock battery is the wrong battery for your intended use.

 

You might also want to pick up a solar charger so that you can at least have some power going back into the battery as you are using it.

 

I left my radio playing at a tailgate for several hours, when the battery started to discharge the music began to cut in an out - signalling the battery was low. turned everything off and still able to start the jeep without a jump.

Most good inverters will have a low battery indicator and/or turn off when your battery is running low to prevent killing your battery.

so there are some safe guards built into most vehicles/products these days to prevent running battery down too low.

 

Good info so far.......thanks guys

 

We pretty much go all out for our tailgates down here on Saturdays. And started with an invertor and quickly moved up to a generator. One of the silent invertor styles.400-900 dollars. I highly recommend it if you have the room. They are not that big. Like a large breifcase and pretty quiet.

How long do you plan on tailgating? If you don't mind starting your car every so often or like stated earlier get a deep cycle.

 

We usually tailgate for about 4 hours. How quiet are the generators you are using?

 

The inverter style generators are pretty quiet. They don't run at full rpm all the time, like the older ones have to. If you are pulling only a small load, it will run only fast enough to power the inverter at that load.

 

They are very quiet and if you put them on the other side of the jeep with the exhaust pointed away you really wont hear much at all. I even have 3 boards with some dynamat type material on them. I put one on the ground below the generator and the other two teepeed over the exhaust side. We dont even hear it. mine last all day without a refill as well. so no need to bring extra gas. The invertor styles are safe for electronics and they have idle controls that fluctuate with the draw.

If you are going to tailgate often get the generator first. much better peace off mind.