hey like all 5th geners, i left my headlights on again... :| anyway. i was wondering when the car is recharging does it charge any faster if you're driving at 3000 vs 1000 etc. also, hypothetically if you had your car on and was just rolling downhill at 60mph, would it automatically charge your car because the engine is in gear and turning at 3k rpm or do you need to gas it to actually charge better?

 

A battery is used mainly to start a car. Then the alternator takes over, it recharges the battery from whats used starting. The battery will only accecpt a constant amp rating. The alternator runs about 85% to 90% and uses the battery as a backup. After a car starts you can pull the battery and it will still run. Voltage regulator inside the alternator controls output to the car.

 

hey thanks for the info. i can draw my own conclusions from your points, thus enabling critical thinking skills

 

Just go buy a A/C charger/trickle charger at Sears or Walmart. I usually just leave it hooked up overnight in the garage on very low charge - with automatic shutoff.

 

Good man.. knows all about the charging system.. you should learn more about drag wings now h:



jfwy man.
:chuckles:

 

If you somehow got a car to do that without self-starting, yes, the alt would be charging the battery.

 

There time i shake my head at some of the stuff on here. Then theres time i hear something i did not know. It's make it worth will to stick around. :wiggle: :bigok:

 

don't EVER EVER EVER pull the battery with the car running. you will most likely fry something electrical in your car. the car will be fine, until the voltage draw increases slightly. with no battery to draw from, the alternator will immediately begin to output much higher amps, and again with no battery to buffer that output, voltage could rise to the 16.0v level, which can mean death for things like ECMs, PCMs, cruise control module, basically most of the IC driven systems that depend on voltage convertors to change the normal 12.0v-14.4v to a steady 5v needed for the ICs to run. throwing above 16.0v at a voltage convertor is almost always above it's operating threshold, and they go pop. bad.

honda alternators can and do output different amps at different times, even shutting off occasionally when there is minimal draw and the battery appears fully charged. don't believe me? hook up a voltmeter to your car and drive around for a few minutes with no accessories on. it will drop to 12.0v once in a while and then will go back up once you hit brake lights or drive long enough for the ignition coil and other little draws to use a little juice outta the battery.

as for driving at different rpms, yes a higher rpm will allow more amps to be produced by the alternator, but only when needed.

for example, if the voltage regulator is setting the alternator output at 20A to combat the draw by various electrical devices (headlights, parking lights, radio, etc) and it is able to produce 20A at idle, then running at 3000 rpm will not make any more power output. however, if you have a massive stereo system and you are doin a huge bass note for extended period of time (lets say 100A draw), you'll find that at idle your volts will be down closer to 12.0v or lower, as the battery is now being drawn since the alternator cannot produce enough power, even though the voltage regulator is trying to set output to 100A. spinning the engine up to 3000 or more rpms in this situation should alleviate the power loss, as the alternator is spinning fast enough to produce the extra requested amps.

this is just an example...as far as i know, no honda alternator is capable of producing 100A at any rpm. that's what hi-output aftermarket alternators are for.

as for the original question...if the engine is spinning, the alternator will produce power, gas pedal pressed or not...the ignition must be on though. the drained battery will charge faster if you are at higher rpms...that's why it's a good idea to take a lap around the block before you shut off a car that was just jumpstarted...this is better than letting a cold car warm up by idling. idling a warmed up car would be fine to charge...but...if the car is already warm...then it just was run...and the battery obviously would still have some juice - headlights won't kill a car THAT fast.

 

I typed it in a little wrong. You can pull the battery if it is not part of the circuit. My bad.

 

ok now that we got the complete understanding on alternators and batteries, i wanna asks something else...
how does jump starting a car work? you roll your car down a hill and leave the ignition on and when you get about 20 mph? you pop it in 2nd and release the clutch and the car starts? why does it start? and what do you do after it starts, press the gas? or is it kinda easy to figure out?