Alternator suggestion?

[jeeper2269 10+ year member]

If I am running the following amps, what size alternator do I need?

Vehicle is a 2021 Jeep Wrangler

Amp 1 - Teramps Smart 3 (3k watts will possibly be running an FI Neo 3.5)

Amp 2 - US Accoustics Barbara Ann (700 watts to fronts)

Upgraded battery a year ago to a

DieHard Platinum AGM Battery: H7 Group Size, 850 CCA, 1000 CA, 140 Min Reserve Capacity, For High Electrical Demands​

Click to read more...

 

[Doxquzme Premium Member]

Depends on the use but a Li-on battery with an isolator between the primary and 2nd batter would probably be a better solution.

Amazon product ASIN B0BYK87LT2
If you decide on an HO alt, email Nicholas Starks at Apex Alternators, he'll send you a quote. If I recall, they start at 250A but a 340A would be fine.

apexalternators@gmail.com

Great service, great products.

 

[jeeper2269 10+ year member]

Depends on the use but a Li-on battery with an isolator between the primary and 2nd batter would probably be a better solution.

Amazon product ASIN B0BYK87LT2
If you decide on an HO alt, email Nicholas Starks at Apex Alternators, he'll send you a quote. If I recall, they start at 250A but a 340A would be fine.

apexalternators@gmail.com

Great service, great products.

Thank you

I appreciate the info

 

[jeeper2269 10+ year member]

Depends on the use but a Li-on battery with an isolator between the primary and 2nd batter would probably be a better solution.

Amazon product ASIN B0BYK87LT2
If you decide on an HO alt, email Nicholas Starks at Apex Alternators, he'll send you a quote. If I recall, they start at 250A but a 340A would be fine.

apexalternators@gmail.com

Great service, great products.

as far as use goes, this is my daily driver. I just listen to hard rock, metal, some country. The old FI Q 12 has been running off a teramps hd 3000.1 and I haven't run into any issues with the stock alternator. Since I got the larger battery, the headlights don't dim at all with hard bass lines. I have seen the voltage drop a bit though, I think in the low 13s or so IIRC

 

[Doxquzme Premium Member]

as far as use goes, this is my daily driver. I just listen to hard rock, metal, some country. The old FI Q 12 has been running off a teramps hd 3000.1 and I haven't run into any issues with the stock alternator. Since I got the larger battery, the headlights don't dim at all with hard bass lines. I have seen the voltage drop a bit though, I think in the low 13s or so IIRC

I, like you, are right on the cusp of what might require an HO Alt upgrade. I'm eyeing this product as it appears to be about 25% less that the comparable XS power product's that I have looked at.

Glowe Voltage - Series 2

Double the power. Half the cost. The future is now.

glowevoltage.com

Not sure about your situation, the idea of paying someone to install the Alt or actually doing the HO ALT upgrade, not appealing to me at all. At the end of the day, for me at my age, i'm paying someone to do the ALT upgrade, the 2nd battery is something that I can (will) do. price difference is negligible at that point.

 

[metalheadjoe 10+ year member]

as far as use goes, this is my daily driver. I just listen to hard rock, metal, some country. The old FI Q 12 has been running off a teramps hd 3000.1 and I haven't run into any issues with the stock alternator. Since I got the larger battery, the headlights don't dim at all with hard bass lines. I have seen the voltage drop a bit though, I think in the low 13s or so IIRC

If your headlights don't dim, you don't need to upgrade anything.
If your voltage doesn't drop below 13v, you don't need to upgrade anything.
Your amp will shut off from low voltage before your battery is too low to start.

Look into LiFePO4. You can run it in parallel with your battery without an isolator.

 

[djdilliodon!]

That truck if I’m not mistaken has a pretty big alternator stock.

 

[metalheadjoe 10+ year member]

That truck if I’m not mistaken has a pretty big alternator stock.

A jeep is definitely not a truck, but every newer vehicle comes with a very big alternator.

 

[djdilliodon!]

A jeep is definitely not a truck, but every newer vehicle comes with a very big alternator.

Is it a car

 

[djdilliodon!]

I’m wrong, it’s classified as a suv. What ever happened to simply just cars and trucks? They got vehicles like they got pro nouns now

 

[HardofWhoring]

Depends on the use but a Li-on battery with an isolator between the primary and 2nd batter would probably be a better solution.

Amazon product ASIN B0BYK87LT2
If you decide on an HO alt, email Nicholas Starks at Apex Alternators, he'll send you a quote. If I recall, they start at 250A but a 340A would be fine.

apexalternators@gmail.com

Great service, great products.

Thank you

I appreciate the info

No, it wouldn't. If you draw more than you recharge you're eventually going to kill your battery. A battery is a storage bank, and an alternator charges.

So if we take 3700watts total:

3700w / .8 (for 80% amp efficiency, which is a rough average, but you can find yours) = 4625w draw.

4625/ 14.4 voltage (The standard running voltage, but newer vehicles aren't always standard) = 321 amp draw.

That's just the stereo (in addition to what the vehicle uses). This is at full voltage when the bass hits. In between those it's drawing a lot less, and usually recharging. Rock and country has a lot more recharge time compared to rap and techno/house/bass tracks. So that's something that is always relative when figuring out what you need. Plus your vehicle is designed to have a bit more than it's full need: ac, EFI, headlights, brakelights, horn, chargers, ECM, etc.. I would personally be looking for something 300-350 amps, 400 if you can even find it.

Now if you absolutely can't find an alt over 300, then what a second battery would do is give you more time, before you needed to turn your stereo down, and let it recharge.

An isolator is going to separate (isolate) the batteries so they are used one at a time. Most people who use them, do so because they have one battery they plan to use till it dies, and want to have a reserve battery. Most audio systems don't use em, because you are only using one at a time, and in relation to a large system, your vehicle doesn't use all that much power, so you might as well get one large battery or similar batteries and wire them together.


Also know, that when you go alt shopping, there's 3 numbers that matter, and two of them aren't price. Amp output at/or near idle, and RPM for full output. Not sure what your options are, but a good alt will do full output around 2K rpm, and most at idle. A cheap ebay alt won't do full output until over 3K rpm, and will do less at idle than your stock alt, (where do you cruise at)? That's the difference between a $200 alt and a $600 alt. Some places can even give you an actual curve. If they can't or won't give you those two numbers, then move on.

 

[jeeper2269 10+ year member]

No, it wouldn't. If you draw more than you recharge you're eventually going to kill your battery. A battery is a storage bank, and an alternator charges.

So if we take 3700watts total:

3700w / .8 (for 80% amp efficiency, which is a rough average, but you can find yours) = 4625w draw.

4625/ 14.4 voltage (The standard running voltage, but newer vehicles aren't always standard) = 321 amp draw.

That's just the stereo (in addition to what the vehicle uses). This is at full voltage when the bass hits. In between those it's drawing a lot less, and usually recharging. Rock and country has a lot more recharge time compared to rap and techno/house/bass tracks. So that's something that is always relative when figuring out what you need. Plus your vehicle is designed to have a bit more than it's full need: ac, EFI, headlights, brakelights, horn, chargers, ECM, etc.. I would personally be looking for something 300-350 amps, 400 if you can even find it.

Now if you absolutely can't find an alt over 300, then what a second battery would do is give you more time, before you needed to turn your stereo down, and let it recharge.

An isolator is going to separate (isolate) the batteries so they are used one at a time. Most people who use them, do so because they have one battery they plan to use till it dies, and want to have a reserve battery. Most audio systems don't use em, because you are only using one at a time, and in relation to a large system, your vehicle doesn't use all that much power, so you might as well get one large battery or similar batteries and wire them together.


Also know, that when you go alt shopping, there's 3 numbers that matter, and two of them aren't price. Amp output at/or near idle, and RPM for full output. Not sure what your options are, but a good alt will do full output around 2K rpm, and most at idle. A cheap ebay alt won't do full output until over 3K rpm, and will do less at idle than your stock alt, (where do you cruise at)? That's the difference between a $200 alt and a $600 alt. Some places can even give you an actual curve. If they can't or won't give you those two numbers, then move on.

Thank you for the detailed response. Lots of info and I appreciate it.

And to clarify, the current setup is the teramps MD 3000.1 powering an older ferrite version FI Audio Q 12.

I am being told the FI Neo 3 will be a significant upgrade from the older Q and I am still researching which teramps amp version would be best to match up. With this upgrade, I am not sure if the current electrical system will handle it as well as the old. I believe the stock alternator is 220 or 240. I did not originally get the tow package, so I am thinking it’s 220.

 

[some dude]

You will never draw 320 amps of current for your 3700 watts.

I ran a 2500 watt amplifier with a 60amp fuse for 2 years.

Now I'm at 3500 total watts, I have a 150amp alternator and a 80AH AGM. My voltage stays above 13v.


I say run your new equipment and see how your voltage does. You might find you don't need to upgrade anything.

 

[jeeper2269 10+ year member]

You will never draw 320 amps of current for your 3700 watts.

I ran a 2500 watt amplifier with a 60amp fuse for 2 years.

Now I'm at 3500 total watts, I have a 150amp alternator and a 80AH AGM. My voltage stays above 13v.


I say run your new equipment and see how your voltage does. You might find you don't need to upgrade anything.

thank you

it will be great if I don't have to hassle with all of that

 

[Doxquzme Premium Member]

I completely agree with Some Dude. I run 3 amplifiers on a system that after evaluating the average current draw, did not need the 250A upgrade. I run a AudioControl ACM 4.300, a Focal FDP 4.600 and a DS18 Hooligan 3K, a DM810, a 2nd battery, a 40AH AGM and a 10 farad stinger hybrid cap (because I had it laying around) and even when showcasing it for the few times a year that someone wants to see what it can do rarely hit above a 60 amp draw. Regular daily driving, 15 to 25 with 40 amp peaks if that. for most people this is a good video that explains what to expect.



Are there times in the summer when I have the AC and everything going, sure, but it's momentary and again, 95% of the time, the momentary extra out put inmost cases would best addressed by additional storage capacity (Li-on if you can afford it - also costly but easier to accomplish) as opposed to the expensive proposition of putting in and upgraded alternator.