power consumption of "off" head unit. - diyAudio
Go Back   Home > Forums > General Interest > Car Audio
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 18th March 2008, 12:48 PM   #1
Dan2 is offline Dan2  South Africa
diyAudio Member
Join Date: Sep 2005
Default power consumption of "off" head unit.

does anyone know how much current is drawn from a head unit when it is off?? (just to keep the memory)

i want to run my head unit off a computer power supply, but i need to make a plan with (probably) batteries to hold the memory of the frontloader. it is going to be portable so it won't be plugged in all the time.
  Reply With Quote
Old 18th March 2008, 01:17 PM   #2
Did it Himself
diyAudio Member
richie00boy's Avatar
Join Date: Nov 2003
Location: Gloucestershire, England, UK
They may vary between models so why not just measure yours? Should take all of 30 seconds with a multimeter.
www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, modules and more.
  Reply With Quote
Old 18th March 2008, 04:11 PM   #3
diyAudio Member
Travis Clarke's Avatar
Join Date: Oct 2006
Location: Alpharetta, (near Atlanta) GA, USA
Send a message via Yahoo to Travis Clarke
Yes, you should probably see somewhere between 25-50mA (.025-.050 A) on average. Just my experience with it.

That's one of the useful bits of information to have when troubleshooting a vehicle in which the battery keeps getting drained. Some customers would never believe it wasn't the head unit draining it until I proved it (and had a number to start with for the typical current draw).

Note: I do mean truly off, when ONLY the BATT wire has voltage applied, not the ACC wire too.
  Reply With Quote
Old 20th March 2008, 06:48 AM   #4
Dan2 is offline Dan2  South Africa
diyAudio Member
Join Date: Sep 2005
ok thanks guys.

as i said i want to have a battery hooked up to keep the memory - i once did an experiment with a capacitor (my old car had a bad battery so the HU's memory would get lost sometimes when starting) connected to the batt wire. the cap dropped down to about 1V (in my test) and then i turned the radio on and the memory was still there.

So i want to parallel some rechargeable batteries (which will be charged when the radio is plugged in) and connect them to the radio. do you think it would work??
  Reply With Quote
Old 20th March 2008, 07:20 AM   #5
diyAudio Member
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
Put a diode in series with the line to the radio/nicd's so that when you start the car,they don't drain-back into the starter motor,etc..
A big cap should work in place of the nicds.
Some kind of big Schottky diode,or fast-recovery type would be best (lower forward-voltage drop)
  Reply With Quote
Old 21st March 2008, 11:45 AM   #6
Dan2 is offline Dan2  South Africa
diyAudio Member
Join Date: Sep 2005
well i had a different solution - i got another car!!! Actually the reason i sold my old Corolla was 'cos someone gave me a really good offer for it.

i still want to know what the lowest voltage is i can use for the batteries.
  Reply With Quote
Old 23rd March 2008, 08:38 AM   #7
Dan2 is offline Dan2  South Africa
diyAudio Member
Join Date: Sep 2005
how would i build the battery charger?? cos i know you get nicd chargers, NiMh chargers etc. whats the difference and what goes into a charger??
  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
What Does Fostex "Rated Input" and "Music Power" mark02131 Full Range 5 13th October 2012 05:18 AM
car head-unit to run home power amplifiers tinkerbell Everything Else 1 29th December 2006 11:31 PM
Fostex "rated input" and "music power" hugz Full Range 12 16th March 2006 04:33 PM
Dukane IB3250 ("two-fifty") high current consumption handy Solid State 0 9th August 2004 04:14 PM
can one buy a head phone "wireless" converter cord? joywrex Parts 0 14th June 2003 04:41 PM

New To Site? Need Help?

All times are GMT. The time now is 09:22 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2