Power cutout

damo642 · 09-30-2005, 03:50 PM

when the car is turned off ie running on the battery my carputer dies if the vloume goes up very loud . this also happens when the car is idling in traffic lights and the volume is loud.now i am aware that the system is drawing too much current.
So how do i stop this from happening?

Damo642

Bugbyte · 09-30-2005, 05:34 PM

Check the voltage while idling. Turn up the volume, measure the voltage. It sounds like your amplifier is drawing a lot of juice and your alternator can't keep up.

damo642 · 09-30-2005, 05:40 PM

yes you are right -
but my question is how do i avoid this problem
my laptop is running witout a battery so when the power cuts out the laptop reboots from scratch.

Damo642

Strgazr · 09-30-2005, 05:54 PM

1st, turn it down. Especially while idling at traffic lights. The people around you don't want to listen to your music anyway.

2nd, get a high output alternator.

DJiK · 09-30-2005, 07:07 PM

3rd, put a battery in... I mean, you already have a laptop, might as well use a battery with it. That'll also keep your computer on when you're starting the car.

damo642 · 10-01-2005, 07:45 AM

i cant put in the laptop battery because that is the principle i use in order for the laptop to start automatically when the ignition is turned on...

can i get a current limiter or...............

damo642

Scouse Monkey · 10-01-2005, 08:18 AM

find another way to get the laptop to start - eg wire up a relay to the power button

damo642 · 10-01-2005, 10:08 AM

i dont want to wire up a relay because that will mean that i need to open the laptop and mod the hardware - this is a no-no for me because its just too risky and not worth it..... although i know i could do it

there must be other options.......

Damo642

Scouse Monkey · 10-01-2005, 10:27 AM

well there is a solution to you there but if you are afraid to open your laptop then you are gonna have to go with something more messy.

How are you currently controlling the power settings on your laptop?

the normal way is to set to standy and then hibernate after so long on battery. I dont see how you can do it without a battery unless you just kill the power. I would look for a port replicator/docking port with a power button or maybe one of those keyboards with a soft power button can be hacked.

turbocad6 · 10-01-2005, 11:01 AM

can't you just use a tank battery in the lead to the laptop..... sounds like its just the intermitant voltage drop that's your problem..... a stiffining cap at the amp may also do the trick....

damo642 · 10-01-2005, 02:08 PM

The way i have the laptop setup is a pin holding a shortcut button on the front of the laptop (used to boot the laptop straight into windows media player) in place because when the battery is removed it auto boots as soon as it gets power. This does not work when the batery is in.

Usually the way i turn off the laptop is by pulling out the key which kills the power immediately. I know this is not ideal but it works perfect for me.
the battery for the laptop has about 15 connections on it - i reckon if i block some of them off i may be able to get the method i use with the batery left in. However i dont have the pin config for the battery on the laptop (Toshiba 2805-s603).

If any of you guys know the standard for these let me know...

BTW i must post some pics of my sys soon -it cost less than 500 euros (because i already had a laptop) and i running flawlessy apart from above issue since June.

Any ideas to my solution .............

Damo642

turbocad6 · 10-01-2005, 02:15 PM

use a small battery in the power circiut won't change anything from the way you have it set up really, just may need to use a diode or a second relay to isolate....

again, a few farads of a cap at the amp may also solve your problem......

......but the way you are doing this isn't ideal & I'd reconsider hooking this up through the power switch...... you are asking for trouble with xp by just killing it every time you power down..... does it survive crank????

numbers · 10-01-2005, 02:41 PM

Your laptop turning off is hardly the problem at hand. Either your sound setup draws WAY too much power and is pulling your entire electrical system with it (this is bad) or you have your laptop powered from the same wire as your amp(s) and you need a bigger gauge wire to lessen the voltage drop. (this isn't necessarily bad, but it might be if the wire or a connection is getting too hot)

Is your laptop powered by the same power wire as your sound system?

You need to measure the voltage at the battery with your music turned way up. If the voltage drops a lot, then you probably have no business driving a car with a sound system that powerful on the street. If it doesn't drop all that much, then you must have your laptop and system on the same wire and you need to run a much larger gauge wire.

turbocad6 · 10-01-2005, 03:09 PM

I'm guessing he's pulling the voltage down too low..... he doesn't seem to want to consider upgrading the alternator & is just looking to "put a bandaid" on it......

yeah, the real problem is his amp is drawing more that his electrical system can handle comfortably.... that'd be my guess.....

damo642 · 10-01-2005, 03:50 PM

where do i start on this reply!! alot of posts in a short time....

"......but the way you are doing this isn't ideal & I'd reconsider hooking this up through the power switch...... you are asking for trouble with xp by just killing it every time you power down..... does it survive crank????"

XP survives the crank no problems whatsoever - works every time -> boots to mediacar in about 45 seconds.

----"a few farads of a cap at the amp may also solve your problem..."

will this work no probs??? how big of a capacitorwould i need??

----"Is your laptop powered by the same power wire as your sound system?"

yes it is using the same power cable....
if i run a second power cable from the ignition key i dont see how this is going to help?

the problem is not from overheating - the only time i have issues is if the car is a low revs ie stoped in traffic or turned off and the amplifier booming!!!

sometimes it does happen at low vol but rarely - i do have the laptop using a wirelesscard and network card and the usb is charging my smartphone....

i am in fairness using alot of juice from the carbattery.....

"I'm guessing he's pulling the voltage down too low..... he doesn't seem to want to consider upgrading the alternator & is just looking to "put a bandaid" on it......

yeah, the real problem is his amp is drawing more that his electrical system can handle comfortably.... that'd be my guess.....
"

this guy hits the nail on the head here .. but it still doesnt solve my problem

"you need to run a much larger gauge wire."

so if i run a "fatter" power cable to the laptop/amplifier you are telling me that i wont have these problems anymore?????

Damo642