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Discussion Starter · #1 ·
I was working outside and thought I'd listen to my sat radio. So I turned on the RER in my WK and listened for about an hour and afterward I needed to run an errand but my battery didn't have enough juice to turn over the engine. Now I have a new (6 month old) 1000 CCA battery so I know the battery is fine.

My thinking is that the RER's LCD backlight display probably uses more power than necessary. Is there a way to shut down the display and just get audio?
 

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While I don't doubt what happened to you, I am a little surprised that the battery would die in that amount of time with the radio on!

I don't think the LCD display was the cause - even if you could turn it off the amount of power that it uses is quite trivial - my guess is at most 20 watts...probably much less.

You could always measure the draw with the stereo on and off, to see if that is the culprit, but, I would think you could run it alone for more than an hour without killing the battery.
 

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Project Six Shooter V2 / ROUSH Prototype Tech
2000 Grand Cherokee 4.0 w/Select-trac
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While I don't doubt what happened to you, I am a little surprised that the battery would die in that amount of time with the radio on!

I don't think the LCD display was the cause - even if you could turn it off the amount of power that it uses is quite trivial - my guess is at most 20 watts...probably much less.

You could always measure the draw with the stereo on and off, to see if that is the culprit, but, I would think you could run it alone for more than an hour without killing the battery.
I don't think I could go 20 mins with out killing mine and im sitting at 1100 cca
 

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Discussion Starter · #5 ·
I recall reading on wkjeeps that you are supposed to pull the RER fuse if parking for 2 weeks or more.
 

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Well, I know LCD screens use next to nothing in the way of power.

I also know that I have run my back seat VES with both the back and front LCD screens on battery for over three hours without starting the jeep and didn't have any problems starting it up afterwards.

Granted, that's with the REC, but I can't see the two systems having that big of a difference.
 

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All Depends on power output from the AMP... People don't realize the draw amplifiers have at the bottom end and that an AMP is essentially putting out A/C current. The amount of voltage comming out depends on the volume but you can kill a battery in 15-20min no problem at higher volumes with a subwoofer in the vehicle.

Turning off the display won't give you any more run time, low volumes will.
 

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Discussion Starter · #8 ·
thanks guys for the replies. I did have the volume up a bit because I was outside the vehicle. I wonder if the hard disk in the RER is drawing power when the radio is on too.

Is there a way to measure the amperage or voltage draw using a simple multimeter?
 

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2005 Jeep Grand Cherokee
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If you have the key on its not just the radio killing the battery. With the key on all of the modules are on. There are numerous run/start relays that are energized. There is a lot going on.
 

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Discussion Starter · #10 ·
push the menu button and then selevt turn off display. it will still display the clock so I doubt it helps power wise.
this seemed to work well, there was a menu option called "Screen saver" that just leaves the clock on. :)
 
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