h/o alternator frustrations, wat would you guys do?

[mcbob 0]

ok so i figured id give em a try and ordered a h/o alt from db electrical. suppose to be 200a at 1200 rpm n 105a at idle, but wats idle to them? im running a sundown sae 1200 v2 at 1 ohm so around 1500w rms. when im driving down the road the most ive seen voltage drop is about .5 volts on very low hard hitting songs. that part is wat i do like. wat i dont like is when i pull up to a stoplight or stop sign voltage sits at 13.1 with nothing on, 12.6-9 with my lights on. if im in park at idle voltage will sit around 13.9 but if i do anything, roll down a window, turn on the air or heat it drops dramatically, windows pull it down to low 13s(thats one window at a time, rolling down multiple windows at idle kills it brings it to like mid 12s. n air or heat put me at about 12.7. but jus the weight of my foot on the gas puts it at 14

is there anything i can do to better it at idle? the alternator shop here said i cant go any smaller on the pulley because there wont be enough surface area for the belt. i really like how the voltage is when im driving but im concerned that im going to kill my batteries(stock duralast upfront and kinetik hc1400 in the trunk). i just keep thinking of senarios that make it seem like i should just get my money back, run stock alt, and just set turn my amp down. i was thinking wat is goin to happen on a really hot or cold day. i dont think ill be able to run my a/c or heat at idle without draining my batteries which really sucks cause it gets f'n cold here in the winter and now its gettin f'n hot. wat would you guys do? got til next tuesday to send it back for full refund

Edited May 25, 2010 by cheddarbob

[ingramk03 1]

I too had an h/o alt from DB Electrical, with same probs as you and wanted more output at idle. Finally got with Dave from DC Power Engineering and now have dual (2) 270XP alts putting out 400 amps at idle. Needless to say, the difference is like night and day, love it. Call them and see what they can do for you, be forwarned, they are pricey, but what can we say.....we chose this expensive hobby.

[Randal Johnson 544]

I'm asking a question here. ok ...

Is the alternator suppost to charge the batteries during or after heavy use? stereo or regular vechicle activities?

I'm wondering how it (alternator)can stop voltage drop when its job is to charge the batteries.

I have five batteries, 2 in front, 3 in rear, on a 200 amp alt. Over a year with no problems.

I'm asking this because it might help the op to understand his problem. Plus I would like to the way this works. I'm an electronics tech. but I'm kinda drawing a blank on this one for some reason. Can somebody please help?

[ChaosWarlord26 5]

An Alternator job is not to charge batteries. But more or less to maintain charge. The alternator is supposed front the amperage needed to run the electrical and the battery/batteries are there for a reserve. So yes in theory if you keep dropping your batteries voltages you will eventually kill them and your alt as well because it was not made to recharge over and over....

[Randal Johnson 544]

oh ... ok, thanks sir.

guess I was just all bass akwards today

Edited May 25, 2010 by Cablguy184

[Wackzirth88 4]

Yea I was just expecting It to be more steady. Thought it would be better then my stock alt in all aspects, not just when I'm driving.

[slim2fattycake 85]

Get real idle output. Go with DC Power. I get 150 amps at idle out of my 4 cylinder.

[GlassWolf 5]

I'm asking a question here. ok ...

Is the alternator suppost to charge the batteries during or after heavy use? stereo or regular vechicle activities?

I'm wondering how it (alternator)can stop voltage drop when its job is to charge the batteries.

I have five batteries, 2 in front, 3 in rear, on a 200 amp alt. Over a year with no problems.

I'm asking this because it might help the op to understand his problem. Plus I would like to the way this works. I'm an electronics tech. but I'm kinda drawing a blank on this one for some reason. Can somebody please help?

the alternator charges the battery(batteries) when the engine RPM is above idle, and voltage is higher than that of the batteries themselves. When the car is running, and above idle, the alternator supplies current to the car, and the battery should be in a charging state.

some notes on electrical systems

check the link above, under the "Electrical" heading. Some of those links may prove informative.

[Wackzirth88 4]

I'm goin to try to bump the idle up a tad see if that helps any. If it doesn't help it's probably going back

[Wackzirth88 4]

Ok bumped the idle up a bit. Seems to be alot better. I drove around til the engine got hot turned on my headlights, voltage now sits 13.5-7 at stops with music a lil over half volume. With the heat all the way up lights on sits at 13.2 at idle. Driving with lights and air on all the way 13.4-6....since I didn't mention in op voltage is 14.3-4 when car first starts once the engine heats up it's 13.9-14.1

Edited May 27, 2010 by zack w