Thread: System Restarts whenever I start my car

Either get a bigger battery, or get a second battery exclusivly for the carputer, and some sort of aux battery controler, to make sure that it charges, and doesn't drain when the car is being cranked.

Have your battery load tested. Sounds like it is losing capacity.

I had my DC-DC psu temporarily plugged into my cig lighter for power. whenever I started the car the computer would reboot. As soon as I found another power source the problem went away.
Some cars turn off all ignition sourced power to start the engine. If you take a look your radio probably cuts off too when you start the engine. I have no idea how old my Batt/Alternator are. All it took for me was getting power from the right place!

I agree with Falcon62Travis....Most car do just that.

Falcon62Travis/cenwesi have probably hit the nail on the head..... but with most cars it does take a bit of battery juice to kick over an alternator..... but seriously is it really such a bit problem anyway?

You guys all have it wrong. I found a simple solution, you don't need to buy a big battery, you don't need to spend 100 bucks on a aux battery, (all though that would work and be effective if you don't mind lugging around another battery!) If your using a DC to DC converter or a DC-AC inverter, chances are it has some threshold voltage at which it shuts down. If you are restarting during your engine start, it is because the voltage drops below that threshold voltage of 8 volts, or 10 or 4 or whatever it happens to be. If you look at it on an oscilliscope during an engine start, you could see what it looks like. The solution I used was to feed my DC-DC converter with a little one way tank circuit low pass filter consisting of a high current Schottky barrier diode and a large filter cap. The schottky barrier diode has a forward operating voltage of .4-.5 volts or so, but it's not a problem. When I start the car the tank capacitor makes up for the loss in voltage. It's pretty easy to make but if you want, I'll make you one for 10 bucks or so.

Before I used this method, MpegBox would restart every time I started my car, even if I just started it as fast as I could with a little jerk of the key.

This will only work as long as your battery doesn't get too drained from powering the mp3 player. I can go and get gas, or run into a mini mart but if I leave the thing sucking 3 amps for more than 10 minutes with the car off, I'm pretty much screwed if I want to start my car. But then again I have a little honda accord battery that has been completly killed a few times.. :-)

Hope this helps.

Jeff_

Yeah, Jeff knows what he's talking about. That's exactly why your PC keeps kicking off/on. In fact, the voltage fluctuations could really mess with electronics if your ignition system didn't temporarily cut out when you turn the key. Going straight to the battery negates the ignition cutout. I, too, plan on hooking straight to the battery.