Need urgent HELP on POWER prob

**BOND007BE** · 12-14-2003, 12:23 PM

hello , see my attachment , its a quick drawing of my setup
TANK CIRCUIT with second battery

ok , eveything works fine

without engine OK
with engine running OK and no reboot while starting.

BUT

whenever i activate another electrical device ex windshieldwipers , or when i elevate the windows the PC gets reset.

i tried the following.

1.bought me a power filter , but it in the power line , SAME problem
2.i connected the ground of the BATTERY to the ground of the second battery to see if there is any change . SAME POBLEM.
3. i removed (while running) the powon/off switch from mobo to see if there is no puls on it , SAME RESULT
4. disconecting the MAIN battery + from the second battery + so completely working from second battery SAME RESULT.

so i am despirate , any tips ?

noise on the ground ? because in my opinion thats the only thing in common.
can i put the power filter instead of the + into the ground line ?

**frodobaggins** · 12-14-2003, 12:50 PM

Make sure your diode isn't reversed
remove that capacitor or move it past your second battery

**lars46** · 12-14-2003, 09:46 PM

I would remove the capacitor. It is not needed when you have a second battery. One other thing, when you apply power to an uncharged capacitor, it pulls a lot of amps. Make sure the current draw when charging isn't more than the diode can take.

**Jackso** · 12-14-2003, 10:58 PM

I concur, you don't need the cap with the setup you have. Also as stated above, check the diode direction and probably replace it once you remove the cap. It may have gotten dammaged when a high current device started if it was installed backwards.

**Mikesz** · 12-14-2003, 11:46 PM

You can also test the capacity of that second battery by disconnectiong the feed from your main battery and time how long the second can sustain the system on its own. Check to make sure the diode is not damaged. You can check it with an ohm meter. Positive lead on car side negative lead on computer side it should have low resistance. Negative lead on car side positive on computer side it should have high resistance.

You might also want to have your main battery and alte1nator load tested before one lets you down. Operating the windows should not cause a significant voltage dip that would restart a computer, nomatter what powersupply.

mike

**Ricky327** · 12-15-2003, 12:27 AM

4. disconecting the MAIN battery + from the second battery + so completely working from second battery SAME RESULT.

WOW you got some strange problems. Good testing as you already tried to eliminate the potential cause.

If this is the case Ill say you may have some connection problems, a short, faulty external device.

Disconnect as much extra external components from the PC. I doubt it very much if its interference causing your PC to reset. The idea is to almost isolate your PC from the car electrical until you find what causing it by reconnecting each part bit by bit as you test them.

Also try un-grounding the whole PC from the car and see the effect...that should work by now.

Best thing is to get the PC working in this configuration first...running the PC from a separate supply. Im sure your car window cant reboot your PC its completely isolated and running from the house

**shakes** · 12-15-2003, 12:28 AM

i agree with mr frodo ... check that the diode isn't backwards...

if you've got a good tank battery it would be able to power the comp and keep it running for a while on it's own ...

however i don't know that it would survive a crank if the diode were backwards ...

hook up a voltmeter to the battery and watch if there is a dip in power when you roll the window up ... if so that's not a good sign.

**Ricky327** · 12-15-2003, 12:32 AM

however i don't know that it would survive a crank if the diode were backwards ...

Having the diode backward almost mean the main battery is not connected at all...The pc would just run off the second battery.

**Jackso** · 12-15-2003, 12:36 AM

"Having the diode backward almost mean the main battery is not connected at all...The pc would just run off the second battery."

Almost, except it would allow the car to draw from the tank battery at that point. Depending on how old the car is and how nearly dead the window motor is, it could cause enough dip in power to cause a reboot, my driver side will dim the lights if the car isn't running.

**Ricky327** · 12-15-2003, 12:37 AM

hook up a voltmeter to the battery and watch if there is a dip in power when you roll the window up ... if so that's not a good sign.

Yes do this, but since you said you are still having the same problems when running with the second battery...do a voltmeter check when running only from the second battery. So you know whats causing the reset, a dip or interference.