Electronics help needed

[Sleeper]

I am having a problem with the power inverter that I am using. It has a low input voltage shut down feature, so when I start the car it shuts itself off killing my laptop. Is there some way I can make some sort of simple electronic device that will keep the inverter feed voltage from dropping when I crank the motor? (capacitor, condensor?)

Thanks
Paul

 

[Sleeper]

ttt

 

[UNGN]

Run a fused line directly to the battery + and ground it to the body somewhere along the way and put a female cigarette lighter plug on it. Use a 3 to 5 amp fuse to keep it safe and store the plug end in your glove box or run it under the center console. Shouldn't cost more than $6 to make.

If your battery goes under 11V trying to start a 8:1 compression 231 cid V6, its time for a new battery

 

[TURBOV6]

You probally got to get one with a better power supply like one with a fully regulated power supply, by having this no matter what voltage it sees the output will not change but it depends how low the voltages drops. Actually a capacitor might help. I would think something in the 50,000uf 20volts should be adequate. Check out a local electronics parts supplier (not radio shack) and ask them what value you should use.

 

[Sleeper]

Thanks for the replies guys. I will try the direct battery connection first and see what happens.
BTW Battery is new

Paul

 

[Sleeper]

Just curious... If I run a larger rating in the cap, say 1 farad. Will this just buy me more time during the drop out? (motor takes a couple of seconds to kick over)

My battery is in the trunk and I suspect that I am going just below the inverters shut off voltage(10.5v) because of the voltage drop due to the batt location. (Eventually I will run a bigger cable)

Paul

 

[TURBOV6]

A 1 farad will increase the time when it discharges but for the amount the inverter draws the 1 farad will be too big (useless) maybe a 1/2 farad is more than enough for you.

And for the battery cable running to the trunk what size is it? And inadequate wire size will cause voltage drop. Minimum size I would think would be a 0 guage welding cable. And make sure you get a really good ground at the trunk and match same guage of ground as the power side.

This could be you problem with the battery cable or grounding problem.

 

[Sleeper]

TurboV6
Thanks for the info. I am running a #2 welding cable for now, (It is a relatively short run considering the size of my car[ see sig]) but plan to upgrade. Trunk ground is good.
Question for you. Is wiring a cap in a DC circuit different ? How should I do this? (Don't want to mess up)

Thanks
Paul

 

[TURBOV6]

#2? 2 guage? It still might be allitle small, can you get a battery tester? Check current and voltage at the battery? When you do this do the same at the alternator see if there is any voltage or current drop.

And for the cap you will have to ground the cap (close as possible to the cap) and the positive will go paralell to the invertor. But will or will not help something else might be wrong. Invertor, bad ground, ect...

Do you have a cap to do a test with it?

 

[Sleeper]

Sorry, I meant # 2 guage. I'm going to do a little voltmeter testing at the batt and alt to check for a voltage drop.
Thanks for the wiring info. I have to go out to the electronics surplus place and buy a cap.

Paul