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aftermarket hu constant power current draw

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=131422
Printed Date: May 03, 2024 at 11:14 AM


Topic: aftermarket hu constant power current draw

Posted By: jaxzin
Subject: aftermarket hu constant power current draw
Date Posted: May 16, 2012 at 8:01 PM

I own a Kenwood KDC-MP435U head unit. Is it normal for the constant power to draw 20ma on this unit?


Just trying to diagnose either a bad battery or current drain on my vehicle. Thanks for the input



Replies:

Posted By: i am an idiot
Date Posted: May 16, 2012 at 8:21 PM
I have not checked one lately, but that wire does power the microprocessor to keep time on the clock and keep all of your settings and preset stations.




Posted By: jaxzin
Date Posted: May 16, 2012 at 9:02 PM
i am an idiot wrote:

I have not checked one lately, but that wire does power the microprocessor to keep time on the clock and keep all of your settings and preset stations.



Let me take that back. So here is the deal. Having issues with a autozone duralast gold battery that is only 6 months old. Battery sat for about 3 weeks since I mostly drive my motorcycle.

Attempted to start this past weekend and it started but the starter turned very slowly. After a quick 20 min drive the battery seemed fine. Once I got home I put a auto shut off 2A trickle charger on it for about 7 hours and the battery worked great for the next few days.

I go out to start it a day after I used it and the battery was dead. Even though it showed 12.5V with a meter....a load test confirmed it was weak. So I charged it again and I tested for current drain. It's sitting right at 75ma but that shouldnt drain it overnight. When I disconnect the radio fuse it drops down to right at 55ma.

I'm thinking the battery has a intermittent bad cell but Autozone won't replace it because every time it goes bad on me by the time I make it to the store it is charged up and tested good.




Posted By: sparkie
Date Posted: May 17, 2012 at 6:01 PM
A 75ma draw is way too high. The generally accepted maximum current draw limit is 50ma. Most new vehicles shouldn't exceed 25ma with only factory equipment. Do you have anything else installed like an alarm or remote starter? I don't believe a 20ma draw from your radio is normal. A clock and radio memory should only draw a few ma. What is your vehicle. Are you using a module to interface the radio into your vehicle?

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sparky




Posted By: jaxzin
Date Posted: May 17, 2012 at 11:32 PM
sparkie wrote:

A 75ma draw is way too high. The generally accepted maximum current draw limit is 50ma. Most new vehicles shouldn't exceed 25ma with only factory equipment. Do you have anything else installed like an alarm or remote starter? I don't believe a 20ma draw from your radio is normal. A clock and radio memory should only draw a few ma. What is your vehicle. Are you using a module to interface the radio into your vehicle?



I was able to do some more testing with a better 3.5 digit meter. Vehicle is a 04 chevy colorado. 560ma draw when battery is first connected, after about 1 minute it drops to 78ma...then after about 30 minutes it drops to 28ma.

I have a Hornet 727T alarm piggy backed off of the factory alarm. The whole radio circuit draws the 20ma. Im not sure how much just the radio itself draws. Either way I am good with 28ma. I interfaced this with a harness from crutchfield when I bought my radio.

I don't have any type of serious draw. With my A/C on max, highbeams on and stereo thumping my voltage at the battery at 2K RPM is right at 14V so my alternator is good.

What i do think I have is a intermittent open cell in this POS Autozone battery. I'm going to drain out a few of the cells and fill them with flat sprite and some salt so I can get a new one.... : )




Posted By: sparkie
Date Posted: May 18, 2012 at 6:28 PM
Check the battery terminals on your truck. The new style battery terminals found on your truck don't always tighten correctly. Make sure that the nut which tightens them, has a tapered and curved bottom on them to force the clamping terminal to squeeze tighter as you turn it. Some of these trucks had a flat bottomed nut which doesn't work correctly. When checking your truck for a battery draw, wait for at least 30 minutes to get a reading. If you have Onstar and it is active,then the readings will jump up every 15 minutes or so and then go back down.


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sparky




Posted By: rjcapt
Date Posted: May 22, 2012 at 9:26 PM
Whatever you do, don't hook the battery leads up reversed (pos to neg) and try to charge it that way. It will instantly ruin your battery.....of course if autozone replaces ruined batteries....I'm just saying what I wouldn't do....

Pete





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