External voltage regulator

[Dafaseles]

So, this may be a stupid question, but for the life of me, I can't find the solution.
So, I have installed a Mechman 400a alt with the 4 pin harness with the PCM bypass. For a battery, I have a Limitless Lithium Cyber 12k LifePo4 battery. I was hoping to get a constant 14.7 volts from this setup but am getting constant 15v.
The Limitless website states not to charge the battery over 14.8v, so, in the name of safety, I need to find a new 4 pin harness and external voltage regulator to set my desired output voltage. For the life of me, I cannot find anything online. I'm probably just r*tarded, and can't find it, or maybe I'm searching for the wrong thing. Or maybe, .2 volts isn't that big of a deal, though, I've read differently (that doesn't mean what I read is accurate), but with the LifePo4 having the reputation it does for not being the safest chemistry, I'm just trying to cover all my bases.
Any help on this would be appreciated.

 

[djdilliodon!]

So, this may be a stupid question, but for the life of me, I can't find the solution.
So, I have installed a Mechman 400a alt with the 4 pin harness with the PCM bypass. For a battery, I have a Limitless Lithium Cyber 12k LifePo4 battery. I was hoping to get a constant 14.7 volts from this setup but am getting constant 15v.
The Limitless website states not to charge the battery over 14.8v, so, in the name of safety, I need to find a new 4 pin harness and external voltage regulator to set my desired output voltage. For the life of me, I cannot find anything online. I'm probably just r*tarded, and can't find it, or maybe I'm searching for the wrong thing. Or maybe, .2 volts isn't that big of a deal, though, I've read differently (that doesn't mean what I read is accurate), but with the LifePo4 having the reputation it does for not being the safest chemistry, I'm just trying to cover all my bases.
Any help on this would be appreciated.

give mechman a call and see if they have external regulators available. Many times the alt builders have them and offer them as an option.

 

[Dafaseles]

give mechman a call and see if they have external regulators available. Many times the alt builders have them and offer them as an option.

I'm going to email them now. It's not on the website though is my worry.

 

[Popwarhomie]

If your current alternator is an internal it will have to be sent back and changed to external setup.

Mechman can set it up to have a 14.8 volt max output without having to go external regulator.

 

[Dafaseles]

If your current alternator is an internal it will have to be sent back and changed to external setup.

Mechman can set it up to have a 14.8 volt max output without having to go external regulator.

Oh OK. That kind of ***** having to send it back. It is what it is though. Gotta get it done right.
I still want the external regulation though. In the future I want to change to 15.5 (or whatever) volts and run LTO

 

[djdilliodon!]

Oh OK. That kind of ***** having to send it back. It is what it is though. Gotta get it done right.
I still want the external regulation though. In the future I want to change to 15.5 (or whatever) volts and run LTO

i wish my car all I had to worry about is voltage. My car has a stupid setup where the alt puts out nothing if load isn’t detected via the fuse box lol. Voltage will sit in the low 12’s. If you put the head lights on then you get full power or you unplug the connector at the alternator and get the Christmas display of lights on the dash 😂.

 

[Dafaseles]

i wish my car all I had to worry about is voltage. My car has a stupid setup where the alt puts out nothing if load isn’t detected via the fuse box lol. Voltage will sit in the low 12’s. If you put the head lights on then you get full power or you unplug the connector at the alternator and get the Christmas display of lights on the dash 😂.

So does mine. It's a 2011 Silverado.
So, when I bought this alt, I spoke to Tony at mechman. GM hasn't changed its alternator mounting since something like 1986. So any year alternator will fit (I think it's just the V8's though). My truck, having a regulated voltage controller, (stock, uses a 2 pin harness to connect to the truck) I can use an alternator for an older module truck with the 4 pin connector. I just had to connect the exciter wire to a 12v switched source. They also have a sort of 2 pin bypass module. I plug that into the stock 2 pin harness, and it fools the truck into thinking it's still in control of the voltage. No battery light and it works perfectly. So I was fortunate in that aspect. Being in California, if I have a battery light on the dash, it'll fail smog.

 

[Popwarhomie]

Oh OK. That kind of ***** having to send it back. It is what it is though. Gotta get it done right.
I still want the external regulation though. In the future I want to change to 15.5 (or whatever) volts and run LTO

Just get 14.8 max and then when you go LTO add two diodes inline to get 15.5.

 

[Dafaseles]

Just get 14.8 max and then when you go LTO add two diodes inline to get 15.5.

Using diodes exceeds my knowledge right now, so please excuse my inexperience.
I would just solder them in line I would assume? And what diodes would you suggest if you don't mind me asking?

 

[Popwarhomie]

Using diodes exceeds my knowledge right now, so please excuse my inexperience.
I would just solder them in line I would assume? And what diodes would you suggest if you don't mind me asking?

Mechman actually sells a plug with diode built in.

H104 Indicator light harness for 1996-2004 GM Truck

mechman, mechman alternators, high output alternator, mechmanalternators, motor swap, universal, custom, car audio, bass, basshead, subwoofer, amps, voltage, alternator, alt,

www.mechman.com

 

[Dafaseles]

Mechman actually sells a plug with diode built in.

H104 Indicator light harness for 1996-2004 GM Truck

mechman, mechman alternators, high output alternator, mechmanalternators, motor swap, universal, custom, car audio, bass, basshead, subwoofer, amps, voltage, alternator, alt,

www.mechman.com

Well, that makes it easy.
So just installing that in between the alternator and the 4 pin harness will up the voltage to 15.5 ish? It doesn't say much in the description on the website

 

[Popwarhomie]

Well, that makes it easy.
So just installing that in between the alternator and the 4 pin harness will up the voltage to 15.5 ish? It doesn't say much in the description on the website

Sorry I linked the wrong one.

P101-L Voltage boost harness for GM 4 pin regulators for a 1 volt increase for Lithium batteries

mechman, mechman alternators, high output alternator, mechmanalternators, motor swap, universal, custom, car audio, bass, basshead, subwoofer, amps, voltage, alternator, alt,

www.mechman.com

 

[Dafaseles]

Sorry I linked the wrong one.

P101-L Voltage boost harness for GM 4 pin regulators for a 1 volt increase for Lithium batteries

mechman, mechman alternators, high output alternator, mechmanalternators, motor swap, universal, custom, car audio, bass, basshead, subwoofer, amps, voltage, alternator, alt,

www.mechman.com

Oh yeah, I saw that. I wonder if my truck can even handle 15.5-16v without step downs. Probably not.
So I emailed mechman, and basically, I didn't let the alternator warm up enough. It's supposed to be 15v at cold start up, then drop to 14.5 when warm. I was just idling in the driveway with the hood open. I thought I let it run for a good while, but probably not. I just kept seeing 15 volts when I would test it, and got really nervous.
So I have another question. Maybe stupid.
Do you think sending 15v to the battery until it warms up is absolutely terrible for the battery? Like, catastrophic failure bad? I really don't know how much of a difference .2 volts can be. I suppose it can be not much, or a hell of a lot

 

[metalheadjoe]

Just get 14.8 max and then when you go LTO add two diodes inline to get 15.5.

Zenrr diodes?

 

[some dude]

Why is voltage higher when cold?
I see 14.2V on my bass knob when near freezing. On warmer days it's around 13.6.
Voltage always falls a few tenths once engine is warm.