Skip to main content ↑ ↓
Topic: Will my cat die? (Read 2434 times) previous topic - next topic

Will my cat die?

i got a simple quick question, which i think I already know the answer to but i need to ask anyway. Will my cat die if i were to have a 1200 watt inverter hooked straight into the battery powering a (from what i can tell 400watt) home theater system in my trunk.

I would be turning this inverter off when the car was not running, but will it take too much juice for the alternator to fill er back up?

and any other problems that you may see happening in the electrical?

Thank you alot

Re: Will my cat die?

Reply #1 –
I can't even begin to understand why you do something like that. :hick:

Re: Will my cat die?

Reply #2 –
your car will explode, and we will feel the shockwave across the world
It's Gumby's fault.

Re: Will my cat die?

Reply #3 –
Ok, a 400-watt home thatre system would probably only peak at 400 watts - the RMS would likely be closer to 40-50 watts, but let's assume anyway that you are using 400 watts worth of that 1200 watt inverter's capacity.

400 watts at 120 volts is 3.63 amps

at 100% efficiency that 3.63 amps at 120 volts translates into 36.3 amps at 12 volts. No electronic circuit is 100% efficient, so let's round up to 40 amps. With the engine not running your battery would not last long with a 40 amp draw.

Even with the engine running you've got a fuel pump (15 amps), an EEC-IV computer and sensors (20 amps), a blower motor (20 amps), headlights (15 amps) and park lights (15 amps). As you can see you'd be really stretching your stock 65 amp alt by adding another 40 amp draw. If you do install the home theatre system I would strongly recommend a 130-amp 3G alt upgrade and a spiral cell battery at the very least
2015 Mustang GT Premium - 5.0, 6-speed, Guard Green - too much awesome for one car

1988 5.0 Thunderbird :birdsmily: SOLD SEPT 11 2010: TC front clip/hood ♣ Body & paint completed Oct 2007 ♣ 3.55 TC rear end and front brakes ♣ TC interior ♣ CHE rear control arms (adjustable lowers) ♣ 2001 Bullitt springs ♣ Energy suspension poly busings ♣ Kenne Brown subframe connectors ♣ CWE engine mounts ♣ Thundercat sequential turn signals ♣ Explorer overhead console (temp/compass display) ♣ 2.25" off-road dual exhaust ♣ T-5 transmission swap completed Jan 2009 ♣

Re: Will my cat die?

Reply #4 –
Just buy a "car" stereo system, and be done with it. :hick:
95 Ranger Splash 2.3
88 Tbird Sport :ies::ies:
5.0 SO, stainless shorty headers, w/ Magnaflow lers. KYB struts, KYB shocks. 5lug conversion from sn95 Mustang, subframe connectors, drilled and slotted rotors, 03 Mach 1 wheels. sequential taillights.140 speedo

Re: Will my cat die?

Reply #5 –
Maybe he wants to be like Pimp My Ride and some of the ridiculous shiznit they put into cars.  "You got a home feater in yo' CAAAR!"

Re: Will my cat die?

Reply #6 –
that's fo shizzle!!  :grinno:
95 Ranger Splash 2.3
88 Tbird Sport :ies::ies:
5.0 SO, stainless shorty headers, w/ Magnaflow lers. KYB struts, KYB shocks. 5lug conversion from sn95 Mustang, subframe connectors, drilled and slotted rotors, 03 Mach 1 wheels. sequential taillights.140 speedo

Re: Will my cat die?

Reply #7 –
no im cheap and have an inverter, speaker wire, a home stereo, and some free time :-p, im prolly gunna end up buying a car stereo anyway

Re: Will my cat die?

Reply #8 –
Ahhh, idle hands are the tools of the devil. :evilgrin:  No good can come of this :hick:

Re: Will my cat die?

Reply #9 –
Quote from: Thunder Chicken

Even with the engine running you've got a fuel pump (15 amps), an EEC-IV computer and sensors (20 amps), a blower motor (20 amps), headlights (15 amps) and park lights (15 amps). As you can see you'd be really stretching your stock 65 amp alt by adding another 40 amp draw. If you do install the home theatre system I would strongly recommend a 130-amp 3G alt upgrade and a spiral cell battery at the very least


Woah hold on here... Since when does the fuel pump draw 15A or the EEC 20A. ?????  While I've not actually measured the EEC draw I'd be suprised if it were more than 4-5 amp, and most of that is going to be the injector current draw. I have run the Walbro pumps on a power supply and found they have a 2-5 amp draw depending on fuel pressure...

Re: Will my cat die?

Reply #10 –
I'm actually going by what they're fused at (in most cars), not their actual draw (which I've never measured). With the EEC-IV I can actually see it being fairly high, though, when you consider the injector drivers, reference voltages, relay drivers, solenoids, etc. As for the fuel pump I don't know what they draw but I do know they draw enough current to burn the wires inside the tank - a rather unpleasant surprise when I replaced the tank hanger a few weeks ago.

I know the car will run on less than 30amps because that's what my remote starter ignition output is fused at. It will blow the fuse if the heater is on, though (or at least it used to until I installed the 75 amp relay). I also know they'll run on as little as nine volts, as I discovered just before my recent replacement alternator...

The radio, HVAC and signal lights will not run at such a low voltage, it turns out. When they first quit I though I had burned another ignition switch, but when I shut it off and tried to restart it I knew the culprit
2015 Mustang GT Premium - 5.0, 6-speed, Guard Green - too much awesome for one car

1988 5.0 Thunderbird :birdsmily: SOLD SEPT 11 2010: TC front clip/hood ♣ Body & paint completed Oct 2007 ♣ 3.55 TC rear end and front brakes ♣ TC interior ♣ CHE rear control arms (adjustable lowers) ♣ 2001 Bullitt springs ♣ Energy suspension poly busings ♣ Kenne Brown subframe connectors ♣ CWE engine mounts ♣ Thundercat sequential turn signals ♣ Explorer overhead console (temp/compass display) ♣ 2.25" off-road dual exhaust ♣ T-5 transmission swap completed Jan 2009 ♣

Re: Will my cat die?

Reply #11 –
I was running 1600 watts RMS in my car for a while with minor dimming with the stock 65 amp alt. I really dont think it would be a problem.