4k watts daily batt or alternator first?

[marcotheclepto 10+ year member]

i can either afford to get some batteries kinetic 2000 3 of them if i drive down to fla to pick em up or i can order a mechman alt. I want this system installed by october get license back then, but i still need to beef up electrical build sub box and add some fiberglassing up front for my mids.

what would you do?

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[audioarsonal 10+ year member]

Batteries first.

 

[Annnarbor84 5,000+ posts]

x2 on the batts. You will have to keep charging them though. I charge mine probably twice a week.

 

[DBBOOM 10+ year member]

Batteries first.

 

[audioarsonal 10+ year member]

x2 on the batts. You will have to keep charging them though. I charge mine probably twice a week.

As long as you drive your vehicle for more then just a few minuites per trip the factroy alt will charge them just fine.Most factory alts put out 120-140 amps so that is plenty to charge 3-4 batteries.But it doesn't hurt to throw them on an external charger occasionally.

 

[Annnarbor84 5,000+ posts]

As long as you drive your vehicle for more then just a few minuites per trip the factroy alt will charge them just fine.Most factory alts put out 120-140 amps so that is plenty to charge 3-4 batteries.But it doesn't hurt to throw them on an external charger occasionally.

Your case may be diff, but I slow charge mine every week. And they need it. When I test to see if my batts need charged, I dont look at their voltage, I could care less. What I do is throw them on a load tester. If they are ran down they will not load test for shit, and then I know it is time to charge.

 

[audioarsonal 10+ year member]

I can tell if I have a good charge just by watching my voltage drop.From my experiance a factory alt is suffecient as long as you don't bang your shit and only drive for 10-15 min per trip.Your case may be differant were you make shorter trips.

As I said an external charger won't hurt but is not needed.

 

[marcotheclepto 10+ year member]

hmm thanks for input i was thinking same think as far as batteries first, no trip will be shorter than 17-18 mins(house to work) and most will be upwards of 30 mins school to work or 45 mins home to school. et cetera i dont have a battery charger at the house, will this be an issue? if its for say a months time? also is it difficult to change alternators out? expensive to have someone else do it for you? im kinda cheap and like to do things myself but have limited tools and experience on this subject.

 

[audioarsonal 10+ year member]

A good battery charger that puts out 30-40amps is going o be kinda pricey 100-200 depending on brand and features.A little 12amp one will do but it will take forever to get a decent charge on them.You can take a roady every once and a while to give them a good charge as well.I think you'll be fine with 2-3 batteries as well as the stock one for electrical back up and your alt should have no problem keeping up.I would suggest an high ouput alt though somewhere down the road.

 

[audioholic 5,000+ posts]

I can tell if I have a good charge just by watching my voltage drop.From my experiance a factory alt is suffecient as long as you don't bang your shit and only drive for 10-15 min per trip.Your case may be differant were you make shorter trips.As I said an external charger won't hurt but is not needed.

You aren't making alot of sense. That 90-140 amp stock alt wont be charging the batteries if his stereo is pulling over 300 amps (4000 watts / 12 volts). Yes music is transient, but with that big of a stereo even 1/2 or 3/4 volume will pull more than 140 amps. And that would be assuming the car itself uses none of the alt's power, which it obviously will. Even if his drive time is 10-15 mins, that's still 10-15 mins of draining more from the batts than the supply produces. The suggestion to put the car on an external batt charger regularly while sitting in the driveway is the only real way to avoid the need for a H.O. alt.
My answer to the OP is.... both. 4kw is not the size system to be skimping on supply power. If you can afford a 4kw system, you should be able to afford the charging system to support it.

 

[audioarsonal 10+ year member]

You aren't making alot of sense. That 90-140 amp stock alt wont be charging the batteries if his stereo is pulling over 300 amps (4000 watts / 12 volts). Yes music is transient, but with that big of a stereo even 1/2 or 3/4 volume will pull more than 140 amps. And that would be assuming the car itself uses none of the alt's power, which it obviously will. Even if his drive time is 10-15 mins, that's still 10-15 mins of draining more from the batts than the supply produces. The suggestion to put the car on an external batt charger regularly while sitting in the driveway is the only real way to avoid the need for a H.O. alt.
My answer to the OP is.... both. 4kw is not the size system to be skimping on supply power. If you can afford a 4kw system, you should be able to afford the charging system to support it.

The only way that will happen is if he drives around playing tones all day.Like you said music is transient so current draw won't be constant after impeadance rise and at 1/2 volume he could expect to see maybe 1800 watts.I don't think thats going to be that big of a strain.Yes the alt may be strained slightly for a short time but the batteries will back that up hence the suggestion of batteries first.

 

[marcotheclepto 10+ year member]

You aren't making alot of sense. That 90-140 amp stock alt wont be charging the batteries if his stereo is pulling over 300 amps (4000 watts / 12 volts). Yes music is transient, but with that big of a stereo even 1/2 or 3/4 volume will pull more than 140 amps. And that would be assuming the car itself uses none of the alt's power, which it obviously will. Even if his drive time is 10-15 mins, that's still 10-15 mins of draining more from the batts than the supply produces. The suggestion to put the car on an external batt charger regularly while sitting in the driveway is the only real way to avoid the need for a H.O. alt.
My answer to the OP is.... both. 4kw is not the size system to be skimping on supply power. If you can afford a 4kw system, you should be able to afford the charging system to support it.

its not like i dont plan to use a HO alt, i just cant afford to get both now. ive been building this system since may, offa mcdonalds pay and just turned up too short when the time came for my license to be reinstated. was suspended for 6 months so i decided to buy a larger system while my car was idle. i will be putting both into the car but would rather not go without a system until i can afford both and i will not be full volume 24/7. i plan to order the alt ~ 3 weeks after putting in whole system, (i only make btwn 150 and 200 a week)

 

[tymoto21 10+ year member]

get the batts... invest in a indash volt meter (maybe $20), and watch your voltage if it drops low turn it down a bit and let the batts charge. you will prob not even need to get the external charger, but it would be nice to have.

 

[marcotheclepto 10+ year member]

get the batts... invest in a indash volt meter (maybe $20), and watch your voltage if it drops low turn it down a bit and let the batts charge. you will prob not even need to get the external charger, but it would be nice to have.

know where i could grab one? any way to steal one offa a capacitor? got an old 8 f cap with one from my first "system" //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[audioholic 5,000+ posts]

The only way that will happen is if he drives around playing tones all day.Like you said music is transient so current draw won't be constant after impeadance rise and at 1/2 volume he could expect to see maybe 1800 watts.I don't think thats going to be that big of a strain.Yes the alt may be strained slightly for a short time but the batteries will back that up hence the suggestion of batteries first.

First off, you are guessing at 1800 watts. Second, even if your 1800 watt (average) guess was correct, at 12 volts that's 150 amp current draw, on a stock alt that is likely less than that, and also must support the car itself. You are trying to convince us that a stock charging system/alt can support a 4kw system due to transients and imp rise, this just tells me you have little to no experience with such a situation. Third, adding more batts to a system whose power supply is insufficient will only prolong the inevitable, dead batts.
Impedance rise does not affect input current draw for the amplifier, only supplied power to the speakers themselves.

Extra batts will help the situation, but it will still require additional charging with the stereo not playing. That means either regularly driving without the stereo on, or as others suggested, charging the system over night with an external batt charger.