Is my stock alternator enough?

[Kangaroux 5,000+ posts]

Don't mean to hijack this thread, but I have the same question. I'm going to be running an Audipipe 1500d (820 watts rms @ 2 ohm) and the Pioneer amp in my sig (50w rms @ 4 ohm)
My car either has a 60-amp or 75-amp alternator, haven't checked. However, is either one enough?

def. have the big 3 done and put a deka or two in the back if you dont have the cash to be buying a HO alt.

 

[ejschultz 10+ year member]

I'm surprised the supercharged engine doesn't have a more powerful alternator on it.

And for the 60-75amp alternator guy, figure around 1 kW RMS and you're going to need approximately an 83 amp alternator for just the system, not taking into consideration what the engine is going to require to run.

 

[ejschultz 10+ year member]

One other thing, the math that has been done thus far in this thread has been assuming the amps are 100% efficient. Since there's no ideal amps out there, 100% efficiency doesn't exist. You'll have to add on some additional current draw to the calculated currents. One thing you could do is look at your amps and add together their recommended fusing. For example, in my Caprice, my V12 amps have a total of 80 amps and 60 amps, mono and 4 channel respectively, of fusing. That adds up to 140 amps. That the maximum the amplifiers will pull when properly wired assuming they're not going to be playing a fully clipped signal. I'd imagine Alpine rated the fuses with a little headroom as well to prevent blown fuses all the time so I'd imagine that I could probably drop like 30 amps off that for normal, unclipped, full tilt music. Playing tones rather than music will get you a lot closer to the rated current because your amp will be providing a more continuous power. On music, you will probably never get full power from your amps.

 

[Chriszle 10+ year member]

1600rms/12 volts = 13 amps /.70 (70 percent efficiency of amp)=190 amps. 190 amps is the maximum current the amps should draw at full tilt in a burp scenario(if you dont drop below 12 volts). If your listening to music only you can cut that number in 1/2 (some people say 1/3). If your careful and you monitor your voltage drop, you may be able to get away with a stock alternator if your planning on listening to music only, but I would not recommend cutting it that close. If I was in your shoes, I would at least get a decent battery in back. An upgraded alternator is always the best choice because it will provide your amps with good voltage.

 

[-01limited- 10+ year member]

Both my Caprice and my Jeep have factory HO alternators. Neither came with the HO options, I just upgraded for my systems. They both provide enough power too. You'll probably still get some dimming with a HO alternator and that's just because the voltage regulator (on a CS130D it's an internal regulator) cannot instantly change to keep up with the demand of your system. Once the voltage regulator senses a voltage drop, it then kicks the alternator up a notch to keep up with the demand of the system. People always complain about dimming even with HO alternators. No alternator alone will ever completely kill voltage drop due to the voltage regulator not being ideal. I thought I'd throw that out there for you to keep in mind.

Shed some light on these factory HO alts? the one in my jeep is a 130, do they have bigger ones than that stock?

 

[O.G. D-Wet 10+ year member]

Word. Alt and batt. I know it sux dishin out the money but it's worth it cuz ur gonna Wunna upgrade ur system anyway lol probly end up runnin multiple HO alts like sum of these nuts in here lol

 

[dgaf 10+ year member]

Word. Alt and batt. I know it sux dishin out the money but it's worth it cuz ur gonna Wunna upgrade ur system anyway lol probly end up runnin multiple HO alts like sum of these nuts in here lol

This

I went ahead and put a 280amp alt in my truck, maybe could have gotten away without it, but I plan to change things up in the future, this way I'm covered for whatever I wanna do later.

Also, I bought a new alternator, the place I took it to get installed, asked why I didn't just upgrade the stock alt. I didn't know that was an option, he said yea, they can take out the stock one, open it up, and upgrade the guts. I asked how much, he said roughly one dollar per amp, including labor/install. That would have been about 200 bucks cheaper for me had I known that was an option. If you don't know a shop that will do it, call the best audio shop in town, and ask who they use to upgrade and install alternators, go to who they recommend. I went to two crappy shops before I did that, both places couldn't install it, finally took it to the shop the audio place recommended, they knew everything and were awesome.

 

[ejschultz 10+ year member]

Shed some light on these factory HO alts? the one in my jeep is a 130, do they have bigger ones than that stock?

I'm not quite sure what the factory options are for the WJ. Do you have the 4.0 or the 4.7 in there? Check out nagca.com/forum or jeepforum.com/forum. People there will be more than willing to help you out with stuff like that. They're not as in to audio though so you could probably school some of them to that respect.

ThisI went ahead and put a 280amp alt in my truck, maybe could have gotten away without it, but I plan to change things up in the future, this way I'm covered for whatever I wanna do later.

Also, I bought a new alternator, the place I took it to get installed, asked why I didn't just upgrade the stock alt. I didn't know that was an option, he said yea, they can take out the stock one, open it up, and upgrade the guts. I asked how much, he said roughly one dollar per amp, including labor/install. That would have been about 200 bucks cheaper for me had I known that was an option. If you don't know a shop that will do it, call the best audio shop in town, and ask who they use to upgrade and install alternators, go to who they recommend. I went to two crappy shops before I did that, both places couldn't install it, finally took it to the shop the audio place recommended, they knew everything and were awesome.

Yeah, you can rebuild alternators into a more powerful alternator. The only thing you want to check out when you do that is the case size. You might be able to get a stator, rectifier, and voltage regulator for a higher amperage, but if it's a smaller case alternator, you're going to cause the internals to heat up a lot and that'll cause premature failure. For a lot of alternators, you can find kits online to do it yourself. With most alternators, it's really not that hard to rebuild them. Sometimes, having the correct tools is a different story. If it's something you plan on doing, make sure you, or someone you know can press the bearings into place should you replace them. Also, you may need a set of e-Torx sockets for some alternators. Usually CS130/CS130D from Delco need e-Torx sockets. The internals on an alternator are rather simple to understand. You've got a stator, rotor, brushes, bridge rectifier, capacitor, voltage regulator, and...I think that's it. The rotor spins inside the stator creating a magnetic field. The brushes pick this up in the form of an AC voltage. The bridge rectifier flips the negative part of the sine wave to positive and the capacitor helps smooth it out to completely convert the AC to DC. The voltage regulator makes sure the alternator outputs current at the correct voltage. Pretty simple if you ask me.

 

[-01limited- 10+ year member]

I'm not quite sure what the factory options are for the WJ. Do you have the 4.0 or the 4.7 in there? Check out nagca.com/forum or jeepforum.com/forum. People there will be more than willing to help you out with stuff like that. They're not as in to audio though so you could probably school some of them to that respect.


Yeah, you can rebuild alternators into a more powerful alternator. The only thing you want to check out when you do that is the case size. You might be able to get a stator, rectifier, and voltage regulator for a higher amperage, but if it's a smaller case alternator, you're going to cause the internals to heat up a lot and that'll cause premature failure. For a lot of alternators, you can find kits online to do it yourself. With most alternators, it's really not that hard to rebuild them. Sometimes, having the correct tools is a different story. If it's something you plan on doing, make sure you, or someone you know can press the bearings into place should you replace them. Also, you may need a set of e-Torx sockets for some alternators. Usually CS130/CS130D from Delco need e-Torx sockets. The internals on an alternator are rather simple to understand. You've got a stator, rotor, brushes, bridge rectifier, capacitor, voltage regulator, and...I think that's it. The rotor spins inside the stator creating a magnetic field. The brushes pick this up in the form of an AC voltage. The bridge rectifier flips the negative part of the sine wave to positive and the capacitor helps smooth it out to completely convert the AC to DC. The voltage regulator makes sure the alternator outputs current at the correct voltage. Pretty simple if you ask me.

Mines got the 4.7 in it, I guess I could hop over on jeepforum. I've got an account just havent been over there that much since I've been on this forum.

 

[ejschultz 10+ year member]

What's your username over there? Try nagca.com too. It's a little smaller, but it's dedicated to Grand Cherokees.

 

[-01limited- 10+ year member]

What's your username over there? Try nagca.com too. It's a little smaller, but it's dedicated to Grand Cherokees.

Its the same as it is on here. I joined when I got my WJ.

 

[tc300 10+ year member]

Op, I have the same car... Have ran a mmats dhcx2200.1 for yrs wtih a redtop in trunk along with factory bat and alt with NO DIMMING!!

amp was ran at 1ohm.

Tho after i added a four channel amp there was some dimming on some songs. When I first had everything instaled I did buy a HO alt thinkn I was gona need It but didn't I do prolly need to replace the redtop and or the factory bat, I got five yrs use outa them so!!!

 

[tc300 10+ year member]

Also never really played it while the car was turned off much....

 

[ejschultz 10+ year member]

Its the same as it is on here. I joined when I got my WJ.

Mine's the same on there too. In fact, mine's the same on every forum I'm on. I joined up a few months before I got my ZJ.

 

[Xanthous 10+ year member]

Could you explain how an extra battery would prevent me from needing a new alternator? I need 1600rms, how do I know which battery to buy?

Is it okay if a ho 220 amp alternator to only put out 110 amps at idle?