Barely negligible, and only just enough to accommodate the A/C in the first place!

 

get a kinetik cell. if you need a # i got your man,, better hurry tho..

play it loud,. and get a charger... keep the battery charged is all you can do.

 

Your barley running any power you should be perfectly fine.

 

i ran more power than that with no problems but i do have a red top

 

i run my 2000watts plus my highs on my honda bat for 45mins straight no cranking problems.

 

alright thanks guys!

keep opinions coming

 

There is no way you ran 2000+rms for 45 minutes unless you have a huge battery bank, and still that is a long shot. You either aren't running that much power or it was turned down quite a bit.

 

well what a waste of a convo when you didnt even do it lol.....but at least you know in the future

 

"2000watts plus" in pyramid wattage does not equate to real wattage.


post up your specs. I have a feeling you were maybe running 200w, if that.

 

The whole myth of the "AC being on charges the battery better at idle due to increased RPM's" is in most cases, completely untrue.

As a 12 year Master ASE and Ford Senior Master Technician, I can tell you this from experience and training, AND give you factual tests to prove it.

The compressor drags the engine down when it comes on for the AC. The computer increases the idle air bypass around the throttle plate to keep engine speed from going below a certain threshold so that the vehicle continues to run smoothly and not stall due to the increased MECHANICAL load. However, the increased ELECTRICAL load from the blower motor and the electrical magnetic clutch on the compressor and the electric cooling fans all draw anywhere from 30 to 60 amps all of the sudden. An alternator can barely keep up with the loads to keep the battery above the 12.7 volt range at idle with this occuring on most any vehicle.

Want proof? Warm your car up then let it idle for a couple of minutes with no load. Watch your voltmeter and see that the battery voltage is about 13.X volts. Then, turn on the ac and let the engine settle for about a minute to knock off the battery surface charge. You will see the voltage drop below 12.7 volts (although usually it will should still remain above 12 if your electrical system is healthy). Once you take the engine RPMs up to about 1500 or so, the alternator will then be spinning fast enough to generate the voltage necessary to keep up with the load and keep the electrical system voltage in the 13's (or more).

Try this-if you don't have a voltage readout on your capacitor, hook up your voltmeter to your battery while you have your system turned up but with the engine off. Time how long it takes for the battery voltage to get down to 11.5 or so and that is a quick dirty time estimate for how long you can safely go without running the vehicle before starting it back up. There are some other factors that may affect the time it will take to drop (tempurature, recent charging load, battery age, etc). But this will get you a general time line...